Baseline Environmental Conditions The methods used to collect and

Transcription

Baseline Environmental Conditions The methods used to collect and
Application for an Environmental Assessment Certificate
Waterpower Projects
- 685 -
Cloudworks
October 2011
Baseline Environmental Conditions
The methods used to collect and analyze baseline information regarding terrestrial wildlife, wildlife habitat,
and vegetation for all Three Proposed Projects are described in Section 3.0 of the Keystone EA in
Appendix K. The results of baseline studies for the Big Silver Creek Waterpower Project are summarized
below. A complete description of baseline conditions is provided in the Keystone EA in Appendix K, in
particular Section 4.4 and Section 1.4 of Appendix 1 of that report.
Ecosystem Composition of Project Area
The ecosystem composition and distribution of forest structural stages in the Big Silver Creek study area
are shown in Figure 15-9 and 15-10. The Project area is primarily composed of site series HM (2,687 ha)
and FF (1,095 ha) and structural stages 5 (1,858 ha) and 4 (1,958 ha). Site series HM and FF are
capable as living habitat for western toad and as nesting habitat for Spotted Owl, Northern Goshawk, and
Western Screech-owl in old forest stages. These habitats may also provide cover for grizzly bear, nesting
habitat for Band-tailed Pigeon, and living habitat for tailed frogs when adjacent to suitable creeks.
577000
578000
579000
580000
581000
582000
AD
583000
HQ HM
AD
HQ
AD
AD
HM
584000
RI
HM HM
5508000
HM
FF
HM
RD
HM
HM
HQ
FF
HM
5507000
FF
HM
Legend
HM HM
Intake
HM
HM HM
HM
FF
HM
AM AM
HM
FF
FF
HM
HM
Big
Silver
Creek- Big
Waterpower
Map
4.4.1.a
Silver
Project
Ecosystem
Composition
Ecosystem Composition
AM
HM
HM
AV
588000
HM
HM
HM
HMFF
HM
AV
FF
AV
HM
AV HM
587000
HQ
HM
HM
586000
HM
HM
HQ
FF
AD
PD
585000
DF
HM
HM
5509000
576000
5508000
575000
Powerhouse
5507000
574000
5509000
573000
Transmission Line Route
HM
HM
5506000
HM
HM
Penstock
FF
FF
HM
HM
FF
HM
DF
RO
HM
TA HM
HM
FF
FF AM
HM
RD UR
HM
HQ
HM
DF
Local Study Area Boundary
5505000
5505000
Potential Temporary Borrow/Laydown Area
RD
HM
DF
Headpond
HM
HM
RS
Penstock Tunnel
5506000
HM
Road - Gravel
AM
HM
River - Definite
DF
HM
Large Rivers/Lakes
HM
TA
HQ
TA
DF
HM
HM
FF
HM
FF
DF
5503000
HM
HM
HM
TA
TA
HM
HMHM
AM
HQ
5502000
HQ
HM
FF
FF
FFHM
HM
HM
FF
FF
HQ
HM
HM
HM
AM
FF
HM
FF
HM FF
FF
HM
FF
HQ
HM
ES
AM
HM
HM
DF
HM
RS
HM
FF
RD
FF HQ
AM
HM
FF
HM
5498000
HM
RD
RS
LA
DF
HM
FF
Kent
Harrison Hot Springs
Chilliwack
1
2
3
HQ
HM
FF
574000
HQ
HQ
Kilometres
Scale 1:50,000
Projection: UTM NAD83 Zone 10
HM
DF
UR
DF
573000
SS
RS
RS
HM
DF
DF
HM
RS
HM
575000
5497000
HM
0
HM
HM
HM
Maple Ridge
Pitt Meadows Mission
AM
DF
HM
RI
RS
HQ
HM
DF
5498000
HQ
HM
HQ
5499000
HM
HM
HQ
Hope
FF
DF
HM
HQ
HM
AM
HM
HQ
FF
HM
DF
FF
ake
k
HM
RI
HQ
e
re
HM
rC
RS
FF
FF
L
on
ris
AM
ar
AO
FF
HQ FF
HM
lve
Si
FF
HQ HM HM HM
FF
DK
HM
HQ
H
HM
Headpond
Study Area
g
Bi
HQ
RS
Note: See Appendix 1 for explanation of ecosystem codes
ex. HQ, FF
5500000
AM
AO
HM
RS
FF
FF
HQ FF
HQ
HM
FF
HM
FF FF
FF
FF
HM
HM
Figure 15-E
15-9
Figure
5501000
FF
7
FF
FF
FF
FF
6
FF
FF
HM
5501000
HQ
HM
HM
5500000
4;5
DF
5502000
HM
Structural Stage - TEM
1-3
HQ
HM
5499000
HQ
FF
AM
HM
RI
5497000
5504000
DF
RD
5503000
5504000
TA
DFTA
FF
576000
577000
578000
579000
580000
581000
582000
583000
584000
585000
586000
587000
588000
Produced for: Cloudworks Energy Inc.
Produced by: Keystone Wildlife Research
Date: July 18, 2011
566000
567000
568000
569000
570000
571000
572000
573000
574000
575000
576000
577000
578000
579000
580000
581000
GB
BE
DK
HM
HQ
RS
FF
FF
HM
DF
5505000
FF
HM
DK
HM
HM
HM
FF FF
FF
FF
RS
HQ
HQ
RS
FF
FF
FF
HQ
FF
FF
HQ
HM
HM
FF
HM HM
5504000
- Big Silver
Big Map
Silver 4.4.1.b
Creek Waterpower
Project
Transmission
Ecosystem
Transmission Line
Line Ecosystem
Composition
Composition
FF
5505000
HM
5506000
HM
HM
DF
HM
FF
FF
FF
Legend
Intake
Powerhouse
DF
FF
FF
FF
FF
HQ
FF
FF
DF
HM
DF
DF
DF
HM
FF
HM
FFHM
FF
HM
HQ
Transmission Line Route
5504000
5506000
HM
FF
DF
DF
Penstock
Local Study Area Boundary
HM
HM
HQHQ
HM
TA
DF
SS
DF
5502000
DF
DF
FF
FF
DF
FF
FFHM
HQ
HQ
HM
HM
FF
HQ RD
HQ
FF
Large Rivers/Lakes
HM
HM
HMHM
FF
AM
HM
HM
HQ
River - Definite
Structural Stage - TEM
5502000
HQ
DF
HQ
HM
HM
FF
HM
1-3
4;5
FF
HQ
FF
AM
OF
HM
HM
HM
FF
FF
HQ
Ha
rr
FF
HM RS
HM
HM
FF
HQ
RS
HM
HM HQ
HM
5500000
HM
FF
HM
HM
5501000
HQ
FF
HM
HM
HM
HQ
HQ
HQ
HM
HM
HM
is
on
La
ke
AM
AO
7
HM
AM
RS
DF
FF
6
HQ
AO
FF
HM HM
HM
HM
5501000
HM
5503000
FF
HQ
5500000
5503000
Road - Gravel
HM
AM
AM
Figure 15-10
Figure
15-F
AM
TA
HQ
LA
HQ
DF
HM
HQ
HM
HQ
HM
HM
HQ
5499000
5499000
HQ
HQ
DF
DF
AM
FF
FF HQ
Note: See Appendix 1 for explanation of ecosystem codes
ex. HQ, FF
HM
FF
Study Area
DF
HM
DF
HM
HQ
e
Lak
on
RS
HM
HM
RS
s
rri
SS
RS
5498000
HM
HM
Ha
5498000
HM
FF
DF
5497000
DF
DF
5497000
HM
DF
HM
FF
HM
HM
HM
RS
DF
HM
FF
HM
HM
HM
FF
HQ
HM
HM
HM
RS
5495000
HM
RS
567000
568000
569000
570000
571000
572000
573000
574000
575000
RS
FF
576000
Chilliwack
1
2
3
Scale 1:50,000
HQ
FF
RS
0
Kent
Harrison Hot Springs
Kilometres
HM
RS
566000
5496000
HM
HM
5495000
5496000
Maple Ridge
Pitt Meadows Mission
HM
Hope
FF
577000
578000
579000
580000
581000
Projection: UTM NAD83 Zone 10
Produced for: Cloudworks Energy Inc.
Produced by: Keystone Wildlife Research
Date: March 11, 2011
Application for an Environmental Assessment Certificate
Waterpower Projects
- 688 -
Cloudworks
October 2011
Wildlife Habitat Suitability Mapping for Project Area
The intake, penstock, powerhouse, headpond, and transmission line will directly affect 128 ha within the
Big Silver Creek Waterpower Project area. That area includes the following buffers:

Intake: 25 m either side, 50 m upstream

Penstock: 25 m either side

Powerhouse: 25 m either side, 50 m downstream

Roads (if not adjacent to powerline or penstock) 6 m

Transmission: 15 m either side.
The Big Silver Creek powerhouse is located within young subhydric forest, while the intake location
comprises currently young mesic forest. The habitat present along the Big Silver penstock route is mostly
young forest.
Wildlife habitat assessments for the seasonal life requisites for selected VECs were completed at ground
inspection form (GIF) plots in the Project area. In total, 99 GIF plots were completed in the Big Silver
Creek Waterpower Project area, and WHA assessments were completed for 80 of those plots. In 78 to 80
of the WHA plots, assessments were completed for red-legged frog, Northern Goshawk, Western
Screech-owl, grizzly bear, and Columbian black-tailed deer. In 34 to 59 of the plots, ratings were
completed for western toad, Bald Eagle, Band-tailed Pigeon, and Spotted Owl. The majority of the plots
were in structural stage 5 and in FF (03) and RS (05) site series.
Habitat suitability mapping for the Big Silver Creek study area is described in detail in Section 4.4.1 and in
Section 1.4 of Appendix 1 of the Keystone EA in Appendix K. Potential environmental effects may occur
where the Project footprints overlap suitable habitat. Habitat suitability of these areas is summarized
below.
Pond-breeding Amphibian Habitat Suitability
The Big Silver Creek transmission line overlaps with less than 1 ha of Moderate-rated habitat and less
than 1 ha of Low-rated habitat. The rest of the facilities are located on habitat rated Nil. There is at least
one wetland within 100 m of existing roads along the proposed powerline route on the west side of
Harrison Lake.
Northern Goshawk Habitat Suitability
The Big Silver Creek transmission line overlaps 7.5 ha of High-rated habitat. The penstock, powerhouse,
intake, headpond, and transmission line overlap 44 ha of Moderate-rated habitat. The remaining facilities
are in habitat rated Low and Nil. Previous timber harvest around Harrison Lake has reduced the amount
of low elevation, old-growth forest in the area. However, there are multiple polygons of High-rated habitat
on the west side of Harrison Lake along the transmission line. These areas are already fragmented by
existing access roads and the transmission line will be located adjacent to the road.
Application for an Environmental Assessment Certificate
Waterpower Projects
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Cloudworks
October 2011
Western Screech-owl Habitat Suitability
Project facilities overlap 33 ha of habitat rated Low. The rest of the facilities are located in habitat rated
Nil. Previous timber harvest has reduced the amount of low elevation, old-growth riparian forest in the Big
Silver area.
Spotted Owl Habitat Suitability
The transmission line will cross 9 ha of High-rated habitat and 4 ha of Moderate-rated habitat. The rest of
the facilities are in habitat rated Low and Nil. Previous timber harvesting has reduced the amount of low
elevation, old-growth forest in the area. Little to no nesting habitat is available in the Big Silver study area,
and Spotted Owls have not been detected in the area for many years.
Grizzly Bear Habitat Suitability
Habitat suitability for grizzly bear was rated up to Class 1 (High) for spring feeding habitat in the study
area.
Spring
The Big Silver transmission line overlaps with less than 1 ha of Class 2 (Moderately High) habitat and less
than 1 ha of Class 3 (Moderate) spring feeding habitat. All other facility footprints are located in habitat
rated Very Low to Nil.
Summer
The transmission line will intersect 3 ha of Class 3 (Moderate) summer habitat. The transmission line,
powerhouse, and penstock footprints will occupy 21 ha of Class 4 (Low) habitat. All other facilities cross
summer habitat that is rated Very Low to Nil.
Fall
The intake, headpond, and transmission line overlap with 3 ha of Class 1 (High) fall feeding habitat. The
transmission line will overlap with 2 ha of Class 3 (Moderate) habitat. The powerhouse, penstock,
headpond, and transmission line will overlap with 23 ha of Class 4 (Moderately Low) habitat. The
remaining area of the footprints occurs in habitat rated Class 5-6 (Very Low to Nil).
Rare Ecological Communities
The transmission line will overlap 5 ha of High-rated habitat and 25 ha of Moderate-rated habitat for rare
ecological communities. The rest of the facilities are sited in habitat rated Low or Nil. Timber harvest and
recreation in this valley has reduced the potential for rare ecological communities in this area.
Application for an Environmental Assessment Certificate
Waterpower Projects
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Cloudworks
October 2011
Rare Plant Species and Habitats
Rare plant surveys were completed in two days in September, totalling 15.5 search hours.
For the proposed transmission line, a 12.5 km stretch was surveyed on the west side of Harrison Lake
and a 3.5 km stretch on the east side. In addition, a linear distance of 2.5 km was surveyed in the area of
the proposed powerhouse and penstock sites.
Surveys were divided between the east and west sides of Harrison Lake. All areas surveyed were within
the CWHds1 variant, as the CWHms1 areas occurred only in a few inaccessible patches within the
Project area. Habitat features sampled included lakeshore beaches, slot canyons (waterfall spray zones),
conifer forest of varying degrees of canopy closure, a wetland, stream margins, rocky cliffs and slopes,
and human-disturbed sites.
In total, 221 taxa were recorded in the area, consisting of 37 lichens, 3 liverworts, 30 mosses, and 151
vascular plants. Of these, 28 are exotic, 150 are Yellow-listed, 2 are Red-listed, 1 is new to science, and
40 have no ranking (see Table 1.4l in Appendix 1 of the Keystone EA in Appendix K of this Application).
The BC status of one vascular plant is unknown as it is potentially new to science and should be treated
as sensitive and rare until its taxonomy is resolved. The non-ranked taxa are all liverworts and lichens.
Special Plants
Twenty plants of Rorippa sp. unknown were found scattered on a lakeshore beach 60 m away from the
proposed transmission line corridor on the west side of Harrison Lake. An additional population was
discovered in the Tretheway Creek Waterpower Project area on alluvial outwash at the mouth of
Tretheway Creek.
In the same lakeshore beach habitat, a germinant of the Red-listed species Berula erecta was found.
This is a previously unknown population and constitutes the second recorded population in the Chilliwack
Forest District (BC CDC 2008).
The moss Fontinalis hypnoides was found stranded in a muddy depression on this lakeshore beach
habitat. Fontinalis may grow attached to rocks, logs, or soil, or can detach and continue to grow as a
floating aquatic. It is one of our largest mosses, sometimes growing to lengths of sixty centimetres
(Lawton 1971). Other populations of F. hypnoides in British Columbia have been recorded in the Peace
Lowlands, the Nicola Valley, the Slocan Valley, and at Agassiz and Harrison Hot Springs. Some of those
populations have been eliminated by development, and others are very old records that have not been
relocated.
Previous disturbance by timber harvest, powerline construction, and the access roads that accompany
them have eliminated or degraded the quality of rare plant habitats that may have been present in the
past.
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Waterpower Projects
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Cloudworks
October 2011
Non-native Species and Disturbed Areas
The habitats along the proposed transmission line on the west side of the lake are mostly disturbed by
logging, an existing transmission line, and long-term intensive recreational use. Much of the area has
been clearcut, with some portions now in young regenerating forest. The overall plant and lichen diversity
was low and 13% of the species encountered were non-native (see Table 4.4.2b in the Keystone EA in
Appendix K of this Application). The vegetation of the cleared strip under the existing transmission line is
very poor habitat for rare plants, owing to the frequent brushing of trees and large shrubs. The
transmission line corridor is vegetated mostly with dense stands of shrubby plants, tree seedlings, and
pioneer species of grasses and forbs, some of them invasive exotic species.
Generalist Habitats
A small number of vascular plant species are extremely abundant and widespread in the understorey of
the CWH coniferous forests that cover the Project area. These species are tolerant of the dense shade
and acidic soils below closed or semi-closed coniferous canopies. The rock types of the area are acidic
and nutrient-poor, and therefore exclude a large portion of potential rare species, especially those that
depend on higher pH or higher concentrations of macronutrients. The riparian forest margins are
infrequently flooded and consist of shrub thickets dominated by Alnus, Rubus, Salix, Populus, and
Oplopanax, with an understorey of Claytonia sibirica, Dryopteris spp., Elymus glaucus, Maianthemum
dilatatum and Cornus canadensis.
Few rare plant species are ever found in addition to the basic coniferous forest understorey flora, and few
species are able to compete with this hyperdominant vegetation. Likewise, lichen diversity in the CWH
coniferous forests is low. Mosses and liverworts tend to dominate the available substrates.
Specialist Habitats
Non-forested Freshwater Wetlands
The non-forested freshwater wetlands in the Project area were few, but are home to a large number of
plants found exclusively in these habitats. There are a number of different wetland habitat types, each
with a specific ecology that favours specialist plant communities. A small marsh wetland on the west side
of Harrison Lake was surveyed. The habitat quality of this marsh has been marginalized by its close
proximity to the road that parallels the lake and an existing transmission line. A small population of the
recently de-listed plant Hypericum majus was found at this site. No other rare species were found in the
non-forested freshwater wetlands surveyed in the Project area.
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Waterpower Projects
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October 2011
Lacustrine Beaches
One beach in the Project area was a mosaic of sandy and cobbly areas, patches of graminoid vegetation,
and muddy areas that are periodically flooded, with driftwood strewn among them. This type of habitat
„patchiness‟ creates an assortment of microhabitats for rare plants. These beaches are usually sparsely
vegetated and are generally home to a wide variety of vascular plant species, where no species truly
dominate. Twenty plants of Rorippa sp. nov. were found scattered along the beach, and the Red-listed
species Berula erecta and Fontinalis hypnoides were found growing in the muddy area of the beach with
sedges.
Waterfall Spray Zones
Slot canyons with waterfall spray zones were encountered and surveyed on the transmission line route on
the west of Harrison Lake. However, no rare species were encountered.
Rare Ecological Communities
Twelve rare ecological communities could potentially occur in the CWHds1 variant in the Big Silver Creek
Waterpower Project area (see Table 1.4e in Appendix 1 of the Keystone EA in Appendix K of this
Application), but none were found during the field program. The Big Silver Creek study area contains 298
ha of High suitability habitat, and 1,438 ha of Moderate suitability habitat, with the remainder rated Low
and Nil.
Wildlife Surveys
Wildlife surveys were completed between May and August of 2007, between May and October of 2008,
and in May and August of 2010. VECs recorded within the Project area include Northern Goshawk, Bald
Eagle, Olive-sided Flycatcher, American Dipper, and Pacific tailed frog. A Great Blue Heron was detected
outside of the Project area near the mouth of Big Silver Creek and Harlequin Duck was detected outside
the Project area. Spotted Owl surveys were not conducted due to a lack of suitable breeding habitat
within areas that would be disturbed. Detailed wildlife survey results are provided in Section 1.4 of
Appendix 1 of the Keystone EA in Appendix K of this Application.
Songbird Survey
Six point-count bird survey stations were completed along the facilities alignment on May 29, 2007. An
additional 22 point-count survey stations were completed in the area of the proposed penstock on June
13, 2007, and 23 point-count stations were completed in the proposed transmission line area on June 14,
2007. In total, 212 individuals of 36 species were detected during the songbird surveys. Bird species
documented represent those that would normally be expected to be present in coastal forest habitats.
Along the transmission line route on the west side of the lake, 34 point-count stations were completed in
the Project area on June 11, 2008. In total, 278 individuals of 38 species were detected during the
breeding bird survey.
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Waterpower Projects
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October 2011
Bird species detected while completing other work (e.g., field-truthing) were recorded as incidental
observations. One Olive-sided Flycatcher was observed, a species listed as Threatened by COSEWIC in
November 2007. One Bald Eagle was recorded during the survey.
Northern Goshawk Surveys
Goshawk surveys were completed on June 13 and August 13, 2007 along the facilities alignment. No
goshawks were detected during surveys, and no other raptors were seen or heard.
Goshawk surveys were completed along the transmission line on the west side of Harrison Lake on June
11 and July 17, 2008. One adult male Northern Goshawk was observed on June 11. Additional survey
time was spent in the area where the goshawk was initially detected, but no goshawks were detected
during the second survey; however, high suitability goshawk breeding habitat was identified in the area of
the goshawk detection. One other raptor, a Red-tailed Hawk, was observed during the second survey.
Western Screech-owl Surveys
Western Screech-owl surveys were completed in the Project area on the nights of May 29/30, August
13/14, and August 26/27, 2007. No owl species were detected.
Harlequin Duck Surveys
Helicopter surveys for Harlequin Duck were conducted along the Big Silver Creek main stem to determine
pair status on May 10, 2007 and brood status on August 2, 2007. There were no bird observations during
the May 10 pair survey and no Harlequin Ducks were observed during either survey. A number of bird
species were seen during the brood survey, including 3 American Dippers, 4 Common Mergansers, 1
Great Blue Heron, 1 Mallard, 1 Red-tailed Hawk, 13 Spotted Sandpipers, and undetermined species of
hawk, duck, and passerines.
A second pair survey was conducted on May 9, 2008 in conjunction with Harlequin Duck surveys along
Shovel Creek. Several species were detected, including American Dippers, Buffleheads, and one Redtailed Hawk. A brood survey was not completed in 2008 due to poor weather conditions. One female
Harlequin Duck was observed along Big Silver Creek; however, this observation occurred outside of the
Project area (approximately 2 km northwest of Shovel Creek).
Pair and brood surveys were performed again on Big Silver Creek in 2010. On May 14, a pair survey
recorded 5 American Dippers and 1 Common Merganser south of the Project area along Big Silver
Creek, and 1 Harlequin Duck north of the Project area along Big Silver Creek. A brood survey on August
5 found 1 Great Blue Heron and 14 Spotted Sandpipers along Big Silver Creek within the study area, and
an additional 1 American Dipper, 1 Belted Kingfisher, 10 Common Mergansers, and 11 Spotted
Sandpipers south of the Project area along Big Silver Creek.
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Waterpower Projects
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October 2011
Raptor/Heron Nest Surveys
Aerial nest searches were conducted the same days as the Harlequin Duck surveys on May 10, 2007,
August 2, 2007, and May 9, 2008. An aerial survey also occurred before leaf-out on March 10, 2009;
however, no raptors, sign of raptors, or nests were observed along Big Silver Creek. Ground surveys
were conducted in conjunction with other field programs. No eagle, hawk, or heron nests or sign were
observed during summer field surveys.
Pond-breeding Amphibian Surveys
Two polygons were identified as potential amphibian breeding habitat in the Big Silver Creek Waterpower
Project area (see Map 4.4.3 in the Keystone EA in Appendix K of this Application). One of the wetlands
was classified in the field as a bog and no amphibians were observed there. The other wetland is
adjacent to the existing West Harrison FSR and observations there included 3 Pacific chorus frog egg
masses, as well as 4 adult and 60 northwestern salamander (Ambystoma gracile) egg masses.
Incidental Wildlife Observations
Black bears and deer were relatively common in the Project area, and one juvenile Sharp-shinned Hawk
(Accipiter striatus) and a Red-tailed Hawk were observed during 2008 field surveys, and appeared to be
hunting. One pika was also observed on the west side of the Project area. One tailed frog was observed
during electrofishing surveys by fisheries crews in Big Silver Creek on October 3, 2006.
Potential Environmental Effects
The potential effects of the Project on wildlife, vegetation, and rare ecological communities can be divided
into direct effects (e.g., mortality, habitat loss, displacement) and indirect effects (e.g., noxious weed
dispersal, increase in hunting/poaching). Potential environmental effects are likely to fall under three main
categories as described below.

Habitat alteration and fragmentation can include: vegetation and habitat removal; maintenance
of early seral habitat; fragmentation of habitats by roads, project facilities, or transmission line
rights-of-way; invasive species establishment; introduction of silt or other deleterious substances
to aquatic habitats; and introduction of harmful substances into the environment.

Disturbance and/or displacement resulting from loud construction-related activities (e.g.,
blasting, helicopter use, and excavation) can disrupt dispersal, nesting, denning, hibernation, and
foraging, in both the construction and operation Project footprints, as well as in adjacent habitats
that are not directly affected by the Project. Human activity may lead to wildlife displacement and
avoidance of high-suitability habitats by some species, and increased stress to wildlife that
remain in the area. This can result in fitness and energetic consequences for individuals and/or
populations of affected species.
Application for an Environmental Assessment Certificate
Waterpower Projects

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Cloudworks
October 2011
Access management and mortality: increased road use can lead to an increase in disturbance
or possibly an increase in vehicle-related wildlife mortality. Road upgrades and new road
construction can improve access into previously inaccessible areas, which can increase hunting
and poaching, and further displace wildlife due to increased recreational activity. Smaller, less
mobile species (small mammals, reptiles, and amphibians), juveniles/eggs, and species with very
small home ranges may suffer direct mortality related to construction equipment and clearing. In
addition, the presence of humans may provide attractants (i.e., garbage) that lead to problem
animals (e.g., black bears), which may result in problem animal mortality. Avian species may
suffer direct mortality from power line interactions such as collisions or electrocution.
During the operations and maintenance phase of the Project, concerns regarding habitat
alteration/fragmentation, displacement/disturbance, and access management/mortality will continue to
exist, but for the most part these interactions will have less potential for resulting in adverse effects than
during the construction phase, because the work force will be smaller and activities will be less frequent.
Nonetheless, potential operational effects include more long-term effects that can continue to degrade the
surrounding habitats, increasing pressure on species already rare on the landscape. Decommissioning
effects would typically be similar to those occurring during the construction phase.
Habitat Alteration and Fragmentation
Habitat Loss and Alteration
Much of the area around the Project has a long history of logging resulting in large areas with younger
forest. There are still a few patches of older forest remaining, but these are generally at higher elevations.
Habitat loss has been identified as the primary threat to species at risk in Canada and can have a
negative impact on both populations and communities (Venter et al. 2006; Eigenbrod et al. 2008a).
Removal of vegetation and earthworks may affect local populations of wildlife species with small home
ranges or specific habitat needs. Alteration and loss of habitat can also lead to an increase in predation,
decrease in security cover, decrease in food supply, changes in microclimates and hydrology, and
removal of some foraging areas.
Microclimate alterations can be associated with a change in shade, temperature, and moisture retention.
This could have a negative effect on rare plants and less mobile wildlife species such as amphibians and
Pacific sideband that rely on vegetation, litter fall, and CWD for thermoregulation, moisture and cover
(Gallant et al. 2007; COSEWIC 2006).
Blasting through rock cliffs, rock outcrops, and talus slopes could potentially remove thermal habitats for
snakes, and possibly result in direct mortality.
Two beaches located on the west side of Harrison Lake offer perhaps the highest quality of habitat for
rare plants. One beach is located on the north side of Tretheway Creek near the powerhouse, where
Rorippa sp. nov. was observed. This species was also observed south of Tretheway, close to the
proposed transmission line, along with the Red-listed Berula erecta.
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The population of Fontinalis hypnoides found on the lakeshore beach habitat is likely to be a part of a
larger population around the shores of Harrison Lake. One other sub-population of this species was
historically known at Harrison Hot Springs, at the south end of the lake, though the species is probably
extirpated there owing to development and habitat loss. The plants in the Project area were not rooted
where they were found, but were stranded there as water levels receded. Thus, this can be seen as a
transient occurrence. The plants were infertile, so this was also a non-reproducing occurrence. The
source populations of these plants are likely to be found nearby on submerged substrates such as logs or
rocks.
Loss of riparian vegetation and extreme changes in water levels within the diversion reach between the
powerhouse and intake sites may result in negative impacts to a variety of riverine specialists, including
Harlequin Ducks (Heath and Montevecchi 2008; COSEWIC 2006). The loss of riparian vegetation
removes shade and litter fall, thus changing nutrient cycling in the waterbody, and may increase water
temperatures (Richardson 2008). The loss of riparian vegetation also decreases security cover, and may
eliminate suitable foraging habitat for some species (Richardson 2008; Naiman et al. 1993; Mensing et al.
1998). The change in flow can also decrease the width of the stream and potentially increase water
temperature. The change in flow and/or increase in temperature could affect the prey population for some
riverine specialists, although recent literature suggests that a more stable flow in the diversion reach may
also provide more foraging opportunities during operation (Esler et al. 2007).
Removal or alteration of important habitat features may also have detrimental effects on species that
require specific habitat characteristics found in older forest stands. Northern Goshawks and Spotted Owls
require features associated with old-growth stands, such as high canopy closure, snags, and CWD.
These features are particularly important for goshawks in post-fledging areas, where fledglings learn how
to fly and hunt, and during which time they are extremely vulnerable to predation (McClaren 2004).
Conversion of older forests to younger ones may reduce such features on the landscape, as well as
reduce the number of suitable nesting areas for goshawks and Spotted Owls, decrease prey abundance
and accessibility, reduce juvenile dispersal and gene flow, and alter the microclimate conditions within
interior forests (McClaren 2004). Spotted Owls were not detected during surveys at select sites, but one
goshawk was observed along the proposed transmission line on the west side of Harrison Lake.
Cavity-nesters such as Western Screech-owls, as well as Olive-sided Flycatchers who require suitable
perching trees and cavities within mature stands (Campbell et al. 1997), may also be negatively affected
if nest sites are removed when clearing mature and old riparian stands and wildlife trees. No Western
Screech-owls were detected in the Big Silver Creek area, and Project facilities will only remove habitat
rated as Low or Nil.
Finally, a large number of migratory birds breed in temperate forests within British Columbia during the
spring and summer months. These birds nest in a variety of habitats including wetlands, grasslands,
shrub-dominated landscapes, and forests. Vegetation clearing during the breeding season can lead to
nest abandonment and possibly death. While most vegetation clearing is expected during construction,
vegetation maintenance along the transmission line will be done every few years during operations.
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Forest Fragmentation
Habitat loss generally leads to fragmentation of habitats (Andren 1994), which can have long-term
negative consequences for some ecosystems and species. Habitat fragmentation can influence wildlife
populations in several ways, including blocking movement corridors, changing the distribution of species,
reducing the amount of suitable forest interior habitat for some species, reducing gene flow, and
potentially increasing nest predation and parasitism due to edge effects (Robinson et al. 1995; Saunders
et al. 1991).
Fragmentation can affect migration, mate selection, and dispersal between drainages and reduce the
ability of species to travel between areas of high quality habitat, particularly for species that avoid open
areas. Fragmentation creates more edge habitats, which may facilitate access for edge-dwelling
predators, such as Great Horned Owls (Bubo virginianus), Red-tailed Hawks (Buteo jamaicensis), and
raccoons (Procyon lotor). Increased predator access could increase predation rates on adult and juvenile
goshawks (McClaren 2004) and other animals. Red-tailed Hawks may also indirectly compete with
goshawks for suitable nest sites, especially in small, isolated forest patches, since goshawks typically
nest further from edges, while Red-tailed Hawks nest adjacent to clearings (Northern Goshawk Recovery
Team 2008).
Species that are better adapted to edge habitats, such as Barred Owls, may also increase with increased
fragmentation and could potentially displace species such as Spotted Owls (Kelly et al. 2003). Spotted
Owls are considered to be an interior forest species (i.e., they live well away from the edge of forest
stands) and generally avoid open areas, flying within and underneath the canopy of adjacent forest
stands. It is believed that owls avoid open areas to reduce the risk of predation by predators that use
forest edge habitats (e.g., Great Horned Owls) (Forsman et al. 2002). Decreased habitat connectivity is
associated with lower owl productivity, lower juvenile dispersal success, an increase in inter-specific
competition (e.g., from Barred Owls), and an increase in predation (SOMIT 1997). Other species such as
Olive-sided Flycatchers may benefit from increased edge habitat, so long as mature stands with suitable
snag and cavity trees are maintained along and near habitat edges (Robertson and Hutton 2007).
Habitat fragmentation and obstruction can be associated with corridors of unsuitable habitat (i.e., open
roads) that may function as filters (few individuals cross) or barriers (no individuals cross) for some wildlife
populations (Jalkotzy et al. 1997). Construction of a 20 m-wide road removes 1 ha of vegetation per 500
m of linear distance (Jalkotzy et al. 1997). Animals with low mobility, such as amphibians, may be
especially sensitive to mortality and reduced movements due to roads, especially where roads bisect
seasonal migrations between aquatic and forested habitats (Waye 1999; Marsh et al. 2005, Eigenbrod et
al. 2008b). Marsh et al. (2005) found roads could reduce gene flow in salamander populations and that
wider roads were greater barriers to gene flow.
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Wildlife species with large home ranges can also be negatively affected by fragmentation. Grizzly bears
avoid areas that are fragmented by development, including areas with roads and other human influences
(Apps et al. 2004). Linear developments create barriers to bear movement and increase mortality,
especially when development exists along valley bottoms (Apps and Hamilton 2002). In particular, Waller
and Serveheen (2005) found that grizzly bears in their study area did not go within 500 m of highways
and Gibeau et al. (2001) found that female bears did not cross high-volume highways. Fragmentation can
prevent wildlife from accessing high quality habitat and suppress genetic diversity by inhibiting normal
mate selection and dispersal activities (Proctor et al. 2005). Black bears are by far the most common bear
species in the study area. Grizzly bears are not known to be resident in the study areas on the east side
of Harrison Lake, although there may be a few transient bears (C. Apps pers. comm., June 2008).
Conversely, roads with little or no traffic (closed roads) may be used as travel corridors by a variety of
wildlife including ungulates (Marcum 1975, cited in Storlie 1996), bears (Smith 1978; Mace et al. 1996)
and wolves (Whittington et al. 2004). Roadside vegetation can provide an attractive source of forage for
bears and ungulates (Jalkotzy et al. 1997), but attractants such as garbage and forage along roads can
also increase risk of collision mortality (Waller and Serveheen 2005).
Invasive Species
Degradation of habitat and deliberate or accidental introduction of invasive plants can promote largescale alterations in plant communities. Continued changes in land use, together with the spread of the
human population, has made it possible for invasive species to increase their ranges, sometimes to the
extent that they crowd out native species and threaten natural habitats. Invasive alien plants and animals
present a growing environmental and economic threat to British Columbia. It is thought that invasive
species are the second greatest threat to species at risk after habitat destruction (Rankin et al. 2004).
COSEWIC estimates that 25% of endangered species, 31% of threatened species, and 16% of species of
Special Concern are negatively affected by invasive species across Canada.
Invasive species are introduced species that are able to out-compete native species and threaten
biodiversity (Rankin et al. 2004). Invasives are typically open habitat species, and are therefore better
adapted to habitat fragmentation and edge habitats (Charbonneau and Fahrig 2004). Many non-native
species out-compete native plants past the germination stage, by growing rhizomatously below ground,
by sequestering water or nutrients more vigorously than natives, or by shading out native plants by
overtopping them. The introduction of invasive species can lower biodiversity, alter nutrient cycling,
change hydrology, and carry diseases to native species (Rankin et al. 2004).
Construction will involve the transportation of materials and machinery through areas of known invasive
species occurrence, which could contribute to the spread of invasive species. Construction may also
occur in areas of previously unidentified invasive species populations, also resulting in their spread.
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Construction equipment and materials may also introduce invasive species into previously unaffected
areas. The roads running along the east and west sides of Harrison Lake and existing power lines in the
area can act as dispersal corridors for non-native species and are likely the primary sources of existing
exotic plant invasion into the study area. The presence of new permanent roads can facilitate the
increase of invasive species along the forest edge (Watkins et al. 2003; Gelbard and Belnap 2003). The
construction of transmission lines and improvements to the road system will potentially increase the risk
for invasive species to become established (Sorensen 1984). Soil disturbance will create areas of
exposed soil that provide favourable seedbed conditions for the establishment of invasive species; alien
species are particularly effective at invading and becoming established in newly disturbed areas.
During operations and maintenance, particularly of the transmission line rights-of-way, maintenance
vehicles may carry and disperse the seeds of invasive plant species (Schmidt 1989; Fraser Basin Council
2004).
Additional detail about non-native and invasive species is provided in Section 6.2.1 of the Keystone EA in
Appendix K of this Application.
A review of known invasive alien plant species (IAPS) locations in proximity to the Project has been
conducted using the invasive alien plant program (IAPP), a web-based mapping and reporting tool
developed by the Province of British Columbia. This tool allows users to both report on and search a
provincial map base for known IAPS locations. A search of all Project areas has been completed and all
recorded IAPS sites and the associated species present on the sites have been identified.
The IAPP has identified a number of known IAPS sites within the Big Silver LU (see maps in Appendix E
of the Hedberg EA in Appendix R). IAPS sites have been identified along construction access routes and
within planned materials staging areas. The storage and movement of construction materials within these
areas increases the potential for transport and spread of the IAPS into the Project area during the
construction phases of the projects.
The existing barge landing located at the mouth of the Big Silver Creek at East Bay on Harrison Lake may
be used as a staging area for construction phases of the Big Silver Creek and Shovel Creek Waterpower
Projects. A number of invasive species have been identified at the barge landing site, including Canada
thistle (Cirsium arvense), Bull thistle (Cirsium vulgare), St. John‟s wort (Hypercium perforatum),
Himalayan blackberry (Rubis discolor), and Spotted knapweed (Centaurea biebersteinii). Additionally, a
number of IAPS sites have been identified along the main access route between the barge landing and
the Project area, including St. John‟s wort, Canada thistle, Common tansy (Tanacetum vulgare), and
Oxeye daisy (Leucanthemum vulgare).
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Introduction of Silt and Other Harmful Substances
Construction activities within riparian zones could potentially lead to a discharge of silt into waterways
within the Project area. Removal of vegetation for Project facilities may also decrease the amount of
water that is intercepted, and subsequently increase the potential for erosion and sedimentation. These
impacts could have long-term effects for some wildlife species, such as amphibians. The effects of
siltation may not be localized to the footprint, but may extend for some distance downstream of the
disturbance, depending on the amount of silt released.
Increased turbidity affects amphibian eggs, larvae, and adults by interfering with respiration, forage, and
shelter (Matsuda et al. 2006). Fine sediments can fill interstitial spaces within streambeds, which can
effectively eliminate important amphibian micro-habitats (Welsh and Ollivier 1998). This is a particular
threat to tailed frog tadpoles that require clear streams with low levels of sediment. Interstitial spaces
provide them with foraging substrates and thermal and predatory refuge (Dupuis and Steventon 1999).
Increased sedimentation in waterways may also prevent tailed frog larvae from adhering to rocks,
eliminating their ability to feed effectively. Fine sediments may alter the food webs of amphibians, and
impair respiration of aquatic amphibians by clogging their gills (Jackson et al. 2007).
Hydrocarbons, coolants, and other fluids found in construction machinery are toxic and may persist in
aquatic and terrestrial environments (Suchanek 1993; Trombulak and Frissell 2000). Pollution by oil,
gasoline, or other waste may affect amphibian breeding sites and lower survivorship. The permeable skin
of amphibians makes them particularly susceptible to harmful chemicals in the environment (Stuart et al.
2004; Blaustein et al. 2003). Hydrocarbons can interfere with amphibian respiration, cause liver disorders,
kill food sources, affect metamorphosis and inhibit growth (Lefcort et al. 1997).
Herbicides
Transmission line right-of-way maintenance may include the application of herbicides. Herbicide
application may cause negative effects on plants and wildlife around transmission lines, depending on the
product used and how it is used.
Toxicity of herbicides is often dependent on the herbicide‟s main ingredient, the surfactant used to apply
it, and the wildlife species that is exposed (Perkins et al. 2000; Howe et al. 2004). Only a few ingredients
have been tested adequately to determine their potential effects. The effects of the majority of herbicide
ingredients (including how they interact with each other) are still relatively unknown (Shepard et al. 2004;
Tatum 2004; Guynn et al. 2004).
Herbicides are not a major concern for widespread plant species and plant communities, because the
larger common plant population outside the treated area provides a seed-bank for future re-colonization.
However, rare plants and rare ecosystems are, by definition, uncommon on the landscape. Non-targeted
herbicide applications that occur in areas that contain rare plant species could potentially extirpate the
species locally.
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The use of herbicides may change invertebrate community composition, and reduce invertebrate species
diversity and abundance (Freemark and Boutin 1995; Taylor et al. 2006). The effects on vegetation may
also reduce the availability of berries and preferred forage plants for wildlife (Hamilton et al. 1991; Gagne
et al. 1999; Kelly and Cumming 1992, 1994), which may cause diet shifts and displacement of wildlife
species (Freemark and Boutin 1995).
Amphibians are particularly susceptible to the potential negative effects of herbicides due to their aquatic
life habit, permeable skin, and unprotected eggs (Bishop and Pettit 1992). Herbicides are known to cause
mortality in amphibians (both terrestrial and aquatic) if they are applied in sufficient concentrations (Chen
et al. 2004; Relyea 2004, 2005a, 2005b, 2005c). In addition, herbicide applications to aquatic vegetation
could result in short-term changes in vegetation abundance and potentially long-term changes in
vegetation diversity and composition within aquatic habitats. The presence of vegetation, especially
emergent vegetation, within aquatic habitats is important for a number of amphibian species during
breeding, as well as for providing security cover for adults and juveniles.
Disturbance and/or Displacement
Loud construction-related activities, such as drilling, blasting, excavation, helicopter use, and tree falling,
may disturb a variety of wildlife depending on the type of activity, how close the activity is, the frequency
of the activity, and the species‟ susceptibility to disturbance (Swaddle and Page 2007; Frid and Dill 2002;
Oehler et al. 2005; Delaney and Grubb 2004).
Raptor species and Great Blue Herons are sensitive to loud noises in close proximity to nest sites and
may abandon nests in response to disturbance. Nest abandonment can have fitness and energetic
consequences (Hayes and Buchanan 2001). Northern Goshawks and Bald Eagles are particularly
sensitive during the early stages of nesting, including courtship, nest building, and egg-laying (McClaren
2004; USFWS 2006), although eagles will often acclimatize to the disturbance if it is perceived to be nonthreatening. Raptors are less likely to abandon nests during the late incubation and nestling periods.
However, if adults are startled and flushed from nest sites, eggs and young will become vulnerable to the
elements and to predators, and nestlings may be inadequately fed (McClaren 2004; USFWS 2006).
Harlequin Ducks changed patterns of habitat use and displayed increased vigilance and flight behaviour
during white-water rafting activity in Jasper National Park (Hunt 1995, as cited in Jalkotzy et al. 1997),
and a long-term decline in one Harlequin Duck population was correlated with an increase of recreational
boaters (Clarkson 1992, as cited in Jalkotzy et al. 1997). This suggests that other human activities, such
as construction and maintenance, may also lead to behavioural changes by Harlequin Ducks.
Deer may also be displaced from suitable winter habitat if they are disturbed by adjacent activity and
noise, which may have fitness consequences if less forage or shelter is available outside of wintering
ranges.
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Roads are often cited as having the greatest effects of disturbance on wildlife (Jalkotzy et al. 1997).
Repeated disturbances from traffic on roads may cause some species to avoid the area around active
roads, resulting in a net decrease in available habitat, as well as changes in daily and seasonal
movement patterns. Some individuals of some species may habituate to traffic and other human
disturbance, resulting in less avoidance behaviour (Jalkotzy et al. 1997; Thompson and Henderson
1998). Habituation is most likely when the disturbance is low-level, predictable in frequency, and is not
associated with a physical threat. Grizzly bears often habituate to human activities, such as crowds of
bear viewers along roadsides in Yellowstone. However, habituated bears generally encounter humans
more frequently and are therefore more vulnerable to both death by shooting and to becoming
conditioned to associate human beings with food sources (Herrero et al. 2005).
Access Management and Mortality
Increased Hunting Mortality
Increased human presence in the study area due to Project construction and maintenance may result in
increased poaching and hunting of species such as deer, goats, and bears. This may affect local large
mammal populations.
Increased Road Mortality
Roads used during Project construction and operation will be subject to increased vehicle traffic and this
may result in an increase in wildlife mortality due to collisions with vehicles. Adult amphibians may be
killed or injured while crossing roads, and western toads are particularly vulnerable to road mortality as
they are attracted to open areas and may spend a great deal of time on roads (COSEWIC 2002b). If
masses of toadlets migrate across roads while construction traffic is heavy, a significant number of
individuals may be killed in a short period of time. Owls and other birds, small mammals, and ungulates
may also be killed or injured by road traffic. Scavengers such as bears and coyotes might be attracted to
roadkill and may be hit while feeding on the carrion.
Direct Mortality
Some wildlife species may be susceptible to direct mortality during construction and vegetation removal.
Adult amphibians have low mobility and are thought to remain in close proximity to riparian areas
(Richardson et al. 2005; Matsuda and Richardson 1999). In late summer or fall, juvenile western toads
(toadlets) can congregate in large numbers along the sides of breeding pools before dispersing. Clearing
of riparian vegetation and the movement of large construction machinery within riparian areas during
construction may cause direct mortalities of western toads/toadlets and other amphibians. Clearing
activities that occur in low-elevation, deciduous or mixed forests, particularly moist forests containing
bigleaf maple and stinging nettle, could cause direct mortality (particularly where road upgrades or new
road construction occurs) of provincially-listed invertebrates (e.g., Pacific sideband) (BC MOE 2007A).
Direct loss of individuals or whole populations of rare plants is possible if power line poles, facilities, or
new access roads are constructed on areas where rare plants are growing.
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Problem Animal Mortality
The encroachment of human habitation and development into BC‟s natural landscape inevitably leads to
continuing interactions between people and wildlife, often leading to injuries or fatalities for both parties.
This is most evident when people have close encounters with large mammals including ungulates,
cougars, and bears. Many of these encounters are a result of people working or recreating in wildlife
foraging and breeding sites; however, in some instances they occur when wildlife is conditioned to
associate humans with food.
Improper storage and/or disposal of garbage, especially food wastes, may attract bears to construction
sites. Individual bears that learn that people are sources of food can become problems and pose a risk to
people. Feeding any sort of wildlife, including the installation of bird feeders, may attract bears, although
bears are also known to be attracted to substances such as motor oil, fuel, coolants, and paint.
Bears can also become habituated to humans in the absence of food sources (Herrero et al. 2005).
Those bears may reduce their fleeing response in the presence of humans (Herrero 1985; Herrero et al.
2005), resulting in increased human-bear confrontations. The majority of problem bears display a
combination of habituation to humans and attraction to human food sources (Davis et al. 2002). Mother
bears often pass these behaviours onto their cubs, which stay with their mothers for 1 to 3 years (Davis et
al. 2002). The result is a continuing cycle of problem bears.
Avian Mortality from Transmission Line
Avian mortality caused from bird-power line interactions result from either collision or electrocution. In
some cases, collisions and electrocutions of birds have contributed to declines in local and regional
populations, thus raising important concerns for wildlife managers (Bevanger 1994; Janss and Ferrer
1998; Dorin and Spiegel 2005). This may be an important risk for some rare and endangered species
(Bevanger 1994; Savereno et al. 1996; Janss and Ferrer 1998).
Collision
Factors influencing collision risk include the design layout of the power line, species-specific bird
behaviour, and bird population densities. The chance of collision increases if the power lines bisect
seasonal or daily migration paths, such as shorelines and wetlands (Dorin and Spiegel 2005).
Nocturnal or diurnal periods of activity (Bevanger 1994), in-flight manoeuvrability, and the altitude at
which birds fly all affect collision potential (Dorin and Spiegel 2005). According to McNeil et al. (1985) and
Bevanger (1994), power lines located between feeding areas and roosting sites for wetland birds can
have increased risk of bird collision, particularly when a short distance separates the two as birds must
make a short flight at a critical height. Inexperienced birds (Janss 2000) or birds exhibiting territorial or
courtship behaviour can also be at higher risk of collision (APLIC and USFWS 2005) as a result of
decreased alertness.
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Bird collisions are generally a result of poor visibility of suspended wires. Many collisions occur at the
thinner, less visible overhead static lines (APLIC and USFWS 2005). Static wires act as safeguards to
protect against power outages caused from lightning strikes. Savereno et al. (1996) found that 82% of all
collisions in their study were with static wires. These lines are particularly difficult to see during fog, rain,
snow or other weather conditions that decrease overall visibility. If an overhead ground wire is not part of
the design then the risk of bird collision will be reduced.
Electrocution
Electrocutions result when a bird completes a circuit, by coming into contact with both an energized wire
(conductor) and another energized wire or the utility pole. The resultant shock kills the bird and may
cause a power outage or, in extreme cases, a wildfire. Some estimates suggest that 5 to 15% of all power
outages in the United States can be attributed to birds interacting with power lines and utility structures
(Partners in Flight 2005).
Two types of electrocution can occur: phase-to-phase, when the wingspan (usually wrist to wrist) of a bird
comes into contact with two separate conductors; and phase-to-ground, when the bird contacts one
conductor and the grounded support pole. A number of factors influence the risk that birds will be
electrocuted. Species that are more likely to be electrocuted include eagles, hawks, owls, vultures, and
other large birds (APLIC 2006), as their large body sizes have greater chance of bridging the distance
between conductors or between a conductor and a grounded utility pole (Bevanger 1998).
Mitigation
The assessment considers measures to mitigate potential Project effects during construction, operation,
and decommissioning. The location, configuration, and design of Project facilities already integrates
mitigative measures; in particular, the areal extent of disturbance has been minimized, sensitive habitats
and high-quality ecological areas (e.g., climax communities, such as old-growth forest) have been
avoided, and facilities have been sited and/or routed in or adjacent to areas of previous disturbance to the
extent feasible. In addition, facility location and configuration considers maintenance of connectivity
between mature forest stands, and between other high value habitats, such as riparian areas. This
approach will continue to be used for final siting and routing during detailed Project design. During
construction and operation, Cloudworks will employ other avoidance measures, such as selecting the
most appropriate construction methods, equipment, and materials, and timing activities to avoid sensitive
periods.
Additional mitigation measures and Best Management Practices (BMPs) to avoid, eliminate, or reduce
potential environmental effects will be documented in the Construction Environmental Management Plan
(CEMP) and the Operating Parameters and Procedures (OPP). (See Section 20 for more information
about the CEMP and OPP.) The CEMP and OPP also will identify the location of sensitive habitat
features and known rare plant and rare ecological communities, as appropriate.
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The proposed mitigation measures have been developed based on a review of applicable regulatory
requirements and standards, guidelines, codes of practice, BMPs, and prior regulatory approvals of
similar projects, consultation with regulatory agencies (federal and provincial) and First Nations, and
professional experience of the study team.
Mitigation measures are described in detail in Section 6.3 of the Keystone EA in Appendix K of this
Application. For each VEC, mitigation measures are summarized in the residual effects analysis summary
tables in the following section.
Residual Environmental Effects Assessment
The potential residual environmental effects of the Project on all terrestrial wildlife and vegetation VECs
are summarized below. For each VEC, the potential environmental effects, proposed mitigation, expected
residual environmental effect, potential for cumulative environmental effects, and need for follow-up
monitoring are summarized in tabular form. Where residual environmental effects are predicted, they are
characterized using the following key. For more information on specific rating criteria, refer to Section 4 of
the Application and/or to Section 6.4 of the Keystone EA in Appendix K.
Key to Residual Environmental Effects Characterization Criteria
Residual Effect:
Y = Yes
N = No
Reversibility:
R = Reversible
I = Irreversible
Direction:
P = Positive
A = Adverse
Context:
L = Low resilience to disturbance
H = High resilience to disturbance
Magnitude:
N = Negligible
L = Low
M = Moderate
H = High
Probability/Likelihood:
L = Low probability to occur, unlikely
M = Moderate probability to occur
H = High probability to occur, likely
Extent:
S = Sub-local
L = Local
R = Regional
Duration:
S = Short term
L = Long term
P = Permanent
Frequency:
I = Infrequent, Rare
F = Frequent, Regular
C = Continuous
Significance:
S = Significant
N = Not significant
Level of Confidence:
L = Low
M = Moderate
H = High
Cumulative Environmental Effect:
Y = Yes, residual effect of the Project may or is likely to
interact cumulatively with the effects of other projects or
activities
N = No, residual effect of the Project will not or is unlikely
to interact cumulatively with the effects of other projects
or activities
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Pacific Tailed Frog
Pacific tailed frogs are assumed to be in most suitable streams in the Project area. Potential
environmental effects on tailed frogs will be localized at upgraded stream crossings, most notably within
the diversion reach, and during riparian clearing in close proximity to suitable streams. Risks during
operation will include maintenance (i.e., herbicide application) around streams and flow regulation within
the diversion reach itself.
Mitigation for Pacific tailed frogs is expected to reduce environmental effects on aquatic and terrestrial
habitat and potential risk of mortality (notably tadpoles). Stream siltation cannot be completely avoided,
due to the nature of the work within the stream itself. However, well-defined guidelines will be in place
that will direct work in these sensitive areas to prevent measurable increases in turbidity and greatly
reduce the likelihood of a serious event. Residual environmental effects are still anticipated after the
implementation of the mitigation measures, but only during construction. Decommissioning would likely
have similar anticipated effects. None are considered significant. The analysis of residual environmental
effects on Pacific tailed frogs is summarized in Table 15-25.
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Residual Environmental Effects Summary, Pacific Tailed Frog (Big Silver Creek)
Magnitude
Extent
Duration/
Frequency
Reversibility
Context
Probability/
Likelihood
Significance
Confidence
Cumulative Effect?
Follow-up Required?
Proposed Mitigation
Direction
Potential
Effect
Residual Effect?
Residual Environmental Effects
Characterization
Y
A
N
S-L
S/I
R
L
M
N
H
Y
No
Construction and Decommissioning
Habitat loss
and
fragmentation
Clearing will be restricted to carefully flagged areas within
development footprints, except where hazard tree removal is
required.
Disturbed sites will be replanted quickly with ground cover, shrubs,
or trees that are regionally appropriate (once erosion concerns have
been addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions
of Section 3 (Site Development and Management) of the Develop
with Care (BC MOE 2006a) document will be applied, when
appropriate.
Some large CWD will be left in cleared areas and placed along
forested and riparian edges.
Connectivity at stream crossings will be encouraged by limiting
riparian clearing to the access road footprint or penstock where they
cross the stream.
Creek crossings (for creeks with year-round flow) will be surveyed
prior to construction to determine tailed frog presence. Water
diverted around construction site will be returned to the same
stream immediately downstream of the work site when tailed frog
tadpoles are observed.
Construction and maintenance activities in and around
watercourses will conform to Standards and Best Practices for
Instream Works (BC MWLAP 2004), Best Management Practices
for Amphibians and Reptiles (Ovaska et al. 2004), and other
approved work practices, where feasible.
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 708 -
Potential
Effect
Proposed Mitigation
Residual Effect?
Direction
Magnitude
Extent
Duration/
Frequency
Reversibility
Context
Probability/
Likelihood
Significance
Confidence
Cumulative Effect?
Follow-up Required?
Residual Environmental Effects
Characterization
Introduction
of silt and
other harmful
substances
BMPs will be followed for in-stream works.
CEMP will include sections on managing construction waste, spill
prevention, and emergency response.
Maintenance and refuelling will be conducted at an approved
distance away from watercourses.
Equipment will be checked to ensure systems are free of leaks and
in good condition.
All machines working near water will have spill kit, trained operators.
Erosion and sedimentation plan will be in place.
Clearing, grubbing will be minimized, especially in wet weather.
Natural vegetation cover, woody debris, and organic matter will be
retained when possible.
Disturbed areas will be revegetated as soon as possible with
regionally appropriate species.
Y
A
N
S-L
S/I
R
L
L
N
H
Y
No
Direct
mortality
As above for habitat loss.
Permits will be in place to salvage tailed frog tadpoles (or adults)
during diversion of any stream for intake or penstock construction.
Y
A
N
S
S/I
R
L
M
N
H
Y
No
Habitat
alteration,
mortality due
to herbicide
use
CEMP will include pest management plan with guidance for
herbicide use.
Broadcast spraying of chemical defoliants will be avoided around
potential breeding sites.
N
N
No
Flow
regulation in
diversion
reach
Flow within diversion reach will be maintained as defined by
operating parameters set by provincial government. Strategies will
be in place to maintain fish habitat as described in Aquatic
Environment section.
N
N
No
Operation
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 709 -
Western Toad
Western toads were not observed during field studies, but they are likely to occur within the study area.
Toads can breed in a variety of temporary or permanent water features, as long as water is present until
toadlets are ready to disperse. Only a small portion of Moderate suitability breeding habitat overlaps any
Project component. This 0.2 ha area would likely not be affected by construction, as the transmission line
will likely clear-span over that portion of the wetland. Large toad migrations are not anticipated but are
possible at some ephemeral breeding sites. Risks during operation will include maintenance (i.e.,
herbicide application) around streams.
Mitigation to reduce disturbance to potential breeding areas (including an erosion and sedimentation
plan), avoid herbicide use in sensitive areas, and monitor for migrating toads is expected to eliminate
potential environmental effects on western toad populations during construction and operation
(Table 15-26). Decommissioning activities will be similar to those observed during construction. Thus, no
residual environmental effects on western toads are predicted.
Proposed Mitigation
Follow-up
Required?
Potential
Effect
Cumulative
Effect?
Residual Environmental Effects Summary, Western Toad (Big Silver Creek)
Residual
Effect?
Table 15-26
No
No
No
Construction and Decommissioning
Habitat loss
and
fragmentation
Clearing will be restricted to carefully flagged areas within
development footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate
ground cover, shrubs, or trees (once erosion concerns have been
addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with
Care (BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along
forested and riparian edges.
Connectivity at stream crossings will be encouraged by limiting
riparian clearing to the access road footprint.
Larger culverts or bridge crossings will be used.
Construction and maintenance activities in and around watercourses
will conform to Standards and Best Practices for Instream Works (BC
MWLAP 2004), Best Management Practices for Amphibians and
Reptiles (Ovaska et al. 2004), and other approved work practices,
where feasible.
Cloudworks
October 2011
Potential
Effect
Proposed Mitigation
Cumulative
Effect?
Follow-up
Required?
- 710 -
Residual
Effect?
Application for an Environmental Assessment Certificate
Waterpower Projects
Introduction
of silt and
other harmful
substances
CEMP will include sections on managing construction waste, spill
prevention, and emergency response.
Maintenance and refuelling will be conducted at an approved distance
away from watercourses.
Equipment will be checked to ensure systems are free of leaks and in
good condition.
All machines working near water will have a spill kit, trained operators.
Erosion and sedimentation plan will be in place.
Clearing, grubbing will be minimized, especially in wet weather.
Natural vegetation cover, woody debris, and organic matter will be
retained when possible.
Disturbed areas will be revegetated as soon as possible with
regionally appropriate species.
No
No
No
Increased
road mortality
and direct
mortality
Construction activities will be avoided in/around wetlands (where
amphibian breeding is noted) to extent feasible.
If unavoidable, construction in these areas will be scheduled after
breeding is complete and toadlets/juveniles have dispersed where
feasible and appropriate.
Natural drainage will be maintained to protect wetland hydrology.
If construction cannot be rescheduled, Environmental Monitor will
install fencing to direct amphibian migrations away from roads, or
culverts to be installed to direct amphibians safely across the road.
These measures will be monitored during peak amphibian activity to
ensure they are effective.
Congregrations and mortality of toadlets/amphibians will be reported
to Environmental Monitor, who will identify problem areas and
implement additional measures (such as fencing), as required.
No
No
See
mitigation
Habitat
alteration,
mortality due
to herbicide
use
Maintenance workers will be informed of potential amphibian use
and/or congregations if maintenance activities occur during the times
of the year when congregations are anticipated.
CEMP will include pest management plan with guidance for herbicide
use.
Broadcast spraying of chemical defoliants will be avoided around
potential breeding sites.
No
No
No
Increased
road mortality
Maintenance work in or adjacent to known locations of amphibian
congregations identified during construction will be scheduled for
times when congregations are absent, to the extent feasible.
Congregrations and mortality of toadlets/amphibians will be reported
to Environmental Monitor, who will identify problem areas and
implement additional measures (such as fencing), as required.
No
No
No
Operation
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 711 -
Red-legged Frog
Amphibian breeding was observed at a wetland on the west side of Harrison Lake, adjacent to the
proposed transmission line, but the species involved were not red-legged frogs. It is possible that redlegged frogs occur in the study area but none were observed during field studies. The transmission line
overlaps 0.2 ha of a Moderate-rated wetland in the area and this is not likely to be affected by Project
construction or operation, as the transmission line will likely clear-span over that portion of the wetland.
Mitigation to avoid wetlands, maintain wetland hydrology and water quality, and avoid herbicide use in
sensitive areas is expected to avoid the potential for residual environmental effects to red-legged frogs
during construction and operation (Table 15-27). Decommissioning will be similar to construction. No
residual environmental effects on red-legged frogs are predicted.
Proposed Mitigation
Follow-up
Required?
Potential
Effect
Cumulative
Effect?
Residual Environmental Effects Summary, Red-legged Frog (Big Silver Creek)
Residual
Effect?
Table 15-27
No
No
No
Construction and Decommissioning
Habitat loss
and
fragmentation
Clearing will be restricted to carefully flagged areas within
development footprints, except where hazard tree removal is
required.
Disturbed sites will be replanted quickly with regionally appropriate
ground cover, shrubs, or trees (once erosion concerns have been
addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with
Care (BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along
forested and riparian edges.
Connectivity at stream crossings will be encouraged by limiting
riparian clearing to the access road footprint.
Larger culverts or bridge crossings will be used.
Construction and maintenance activities in and around watercourses
will conform to Standards and Best Practices for Instream Works (BC
MWLAP 2004), Best Management Practices for Amphibians and
Reptiles (Ovaska et al. 2004), and other approved work practices,
where feasible.
Cloudworks
October 2011
Potential
Effect
Proposed Mitigation
Cumulative
Effect?
Follow-up
Required?
- 712 -
Residual
Effect?
Application for an Environmental Assessment Certificate
Waterpower Projects
Introduction of
silt and other
harmful
substances
CEMP will include sections on managing construction waste, spill
prevention, and emergency response.
Maintenance and refuelling will be conducted at an approved
distance away from watercourses.
Equipment will be checked to ensure systems are free of leaks and in
good condition.
All machines working near water will have a spill kit, trained
operators.
Erosion and sedimentation plan will be in place.
Clearing, grubbing will be minimized, especially in wet weather.
Natural vegetation cover, woody debris, and organic matter will be
retained when possible.
Disturbed areas will be revegetated as soon as possible with
regionally appropriate species.
No
No
No
Increased road
mortality and
direct mortality
Construction activities will be avoided in/around wetlands (where
amphibian breeding is noted) to extent feasible.
Natural drainage will be maintained to protect wetland hydrology.
If unavoidable, construction in these areas scheduled after breeding
is complete and juveniles have dispersed where feasible and
appropriate.
If construction cannot be rescheduled, Environmental Monitor will
install fencing to direct amphibian migrations away from roads, or
culverts to be installed to direct amphibians safely across the road.
These measures will be monitored during peak amphibian activity to
ensure they are effective.
Congregrations and mortality of amphibians will be reported to
Environmental Monitor, who will identify problem areas and
implement additional measures (such as fencing), as required.
No
No
See
mitigation
Habitat
alteration,
mortality due
to herbicide
use
Maintenance workers will be informed of potential amphibian use
and/or congregations if maintenance activities occur during the times
of the year when congregations are anticipated.
CEMP will include pest management plan with guidance for herbicide
use.
Broadcast spraying of chemical defoliants will be avoided around
potential breeding sites.
No
No
No
Increased road
mortality
Maintenance work in or adjacent to known locations of amphibian
congregations identified during construction will be scheduled for
times when congregations are absent, to the extent feasible.
Congregrations and mortality of toadlets/amphibians will be reported
to Environmental Monitor, who will identify problem areas and
implement additional measures (such as fencing), as required.
No
No
No
Operation
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 713 -
Rubber Boa
The population size and density of rubber boas in the Project area is unknown. Rubber boas were not
located during the field program, but that was expected given the cryptic nature of the species. Potential
effects on rubber boa, if any are present, include the removal or alteration of habitat and possible direct
mortality during construction. Effects are not expected during operation, and decommissioning activities
will be similar to construction. The removal of habitat is relatively small and any local population is not
expected to be affected, as many of the Project footprints overlap previously disturbed sites and existing
anthropogenic footprints (e.g., roads). No residual environmental effects on rubber boa are expected to
occur after the applied mitigation (Table 15-28).
Proposed Mitigation
Follow-up
Required?
Potential
Effect
Cumulative
Effect?
Residual Environmental Effects Summary, Rubber Boa (Big Silver Creek)
Residual
Effect?
Table 15-28
No
No
No
Construction and Decommissioning
Habitat loss
and
fragmentation,
associated
mortality
Clearing will be restricted to carefully flagged areas within development
footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate ground
cover, shrubs, or trees (once erosion concerns have been addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with Care
(BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along forested and
riparian edges.
Northern Goshawk
One Northern Goshawk was observed during surveys on the west side of Harrison Lake within suitable
nesting habitat, approximately 3 km southeast of Tretheway Creek. The proposed transmission line in
that area is down-slope from the suitable Northern Goshawk nesting habitat, adjacent to the existing FSR
and BC Hydro transmission line. The Project will remove <1% of the High-rated habitat in the Project
area (7.5 of 864.8 ha) and 2% of the Moderate-rated habitat (43.7 of 2,013.8 ha), mostly because of the
transmission line. The permanent removal of this suitable habitat cannot be fully mitigated. A residual
environmental effect is therefore anticipated, but it is not considered significant. No residual
environmental effect is expected from operation or decommissioning. The analysis of residual
environmental effects on Northern Goshawk is summarized in Table 15-29.
Application for an Environmental Assessment Certificate
Waterpower Projects
Table 15-29
Cloudworks
October 2011
- 714 -
Residual Environmental Effects Summary, Northern Goshawk (Big Silver Creek)
Magnitude
Extent
Duration/
Frequency
Reversibility
Context
Probability/
Likelihood
Significance
Confidence
Cumulative Effect?
Follow-up Required?
Proposed Mitigation
Direction
Potential
Effect
Residual Effect?
Residual Environmental Effects
Characterization
Y
A
L
L
L/I
R
L
M
N
H
Y
No
Construction and Decommissioning
Habitat loss
and
fragmentation
Inactive or active nests found in close proximity to construction areas
will be reported to the Environmental Monitor.
Appropriate setback buffers will be established around active nests (if
any are identified) (per BMPs in Demarchi and Bentley 2005, BC
MOE 2006a) and will be monitored during construction, if work must
commence during the breeding season and the active nest is
adjacent to a work site.
Clearing will be restricted to carefully flagged areas within
development footprints, except where hazard tree removal is
required.
Disturbed sites will be replanted quickly with regionally appropriate
ground cover, shrubs, or trees (once erosion concerns have been
addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with
Care (BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along
forested and riparian edges.
Rather than completely removing some large trees near the edge of
a footprint, the possibility of creating snags by “stubbing” will be
considered, providing it is safe to do so.
Mature and old-growth forest will be avoided and existing disturbance
corridors followed, where feasible.
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 715 -
Great Blue Heron
Great Blue Herons were observed in the general vicinity, both outside and inside the local study area, but
no nests were found. Potential environmental effects on Great Blue Heron during construction include
removal of potential nesting habitat and nest disturbance due to noise. Potential effects associated with
operation include interactions with the transmission line. Decommissioning activities will be similar to
construction activities. Mitigation measures, including the removal of perching opportunities near
conductors, will avoid or eliminate potential effects (Table 15-30). Therefore, no residual environmental
effects on Great Blue Heron are predicted.
Cumulative
Effect?
Follow-up
Required?
Residual Environmental Effects Summary, Great Blue Heron (Big Silver Creek)
Residual
Effect?
Table 15-30
Great Blue Heron nests are protected by law; lead regulatory agency
will be consulted if nests are identified in or near (within 500 m) final
Project footprints.
Areas within 500 m of any Project footprints will be surveyed prior to
construction to identify any large stick nests.
Inactive or active nests found in close proximity to construction areas
will be reported to the Environmental Monitor.
Appropriate setback buffers will be established around active nests (if
any are identified) (per BMPs in Demarchi and Bentley 2005, BC MOE
2006a) and will be monitored during construction, if work must
commence during the breeding season and the active nest is adjacent
to a work site.
If a vacant nest is located in a Project footprint and cannot be avoided,
the lead regulatory agency will be consulted to develop a plan to
relocate the nest.
No
No
See
mitigation
The configuration of the conductors on the transmission line poles will
reduce and likely eliminate potential for avian electrocution.
If avian mortality due to collision or electrocution is suspected, the
transmission line will be monitored and preventative measures put into
place, under the guidance of a qualified professional biologist.
No
No
See
mitigation
Potential
Effect
Proposed Mitigation
Construction and Decommissioning
Nest loss
and
disturbance
due to loud
construction
noise
Operation
Avian
mortality
from
transmission
line
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 716 -
Olive-sided Flycatcher
Few observations of Olive-sided Flycatchers occurred during the field program, possibly due to limited
amounts of suitable habitat present in the local study area. Removal of Olive-sided Flycatcher habitat
during construction will be negligible, as much of the forest within the immediate Project area has been
previously cleared due to forestry. Mitigation measures will be in place to prevent destruction of active
nest sites (Table 15-31). Potential effects associated with operation include interactions with the
transmission line. Mitigation measures, including the removal of perching opportunities near conductors,
will avoid or eliminate potential effects. Decommissioning is not expected to affect Olive-sided
Flycatchers. Therefore, no residual environmental effects on Olive-sided Flycatcher are expected.
Cumulative
Effect?
Follow-up
Required?
Potential
Effect
Residual Environmental Effects Summary, Olive-sided Flycatcher (Big Silver
Creek)
Residual
Effect?
Table 15-31
Clearing will be restricted to carefully flagged areas within development
footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate
ground cover, shrubs, or trees (once erosion concerns have been
addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with
Care (BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along forested
and riparian edges.
Mature and old-growth forest will be avoided and existing disturbance
corridors followed, where feasible.
No
No
No
The configuration of the conductors on the transmission line poles will
reduce and likely eliminate potential for avian electrocution.
If avian mortality due to collision or electrocution is suspected, the
transmission line will be monitored and preventative measures put into
place, under the guidance of a qualified professional biologist.
No
No
See
mitigation
Proposed Mitigation
Construction
Habitat loss
Operation
Avian
mortality
from
transmission
line
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 717 -
Bald Eagle
A Bald Eagle was observed along the proposed transmission line route, but no nests were observed
during field studies. Potential environmental effects on eagles during construction include loss of potential
nesting habitat and nest disturbance due to noise. Potential effects associated with operation include
interactions with the transmission line. Decommissioning activities will be similar to construction activities.
Mitigation measures, including the removal of perching opportunities near conductors, will avoid or
eliminate potential effects (Table 15-32). Therefore, residual environmental effects are not anticipated.
Cumulative
Effect?
Follow-up
Required?
Residual Environmental Effects Summary, Bald Eagle (Big Silver Creek)
Residual
Effect?
Table 15-32
Bald Eagle nests are protected by law; lead regulatory agency will be
consulted if nests are identified in or near (within 500 m) final Project
footprints.
Areas within 500 m of any Project footprints will be surveyed prior to
construction to identify any large stick nests.
Inactive or active nests found in close proximity to construction areas
will be reported to the Environmental Monitor.
Appropriate setback buffers will be established around active nests (if
any are identified) (per BMPs in Demarchi and Bentley 2005, BC MOE
2006a) and will be monitored during construction, if work must
commence during the breeding season and the active nest is adjacent
to a work site.
If a vacant nest is located in a Project footprint and cannot be avoided,
the lead regulatory agency will be consulted to develop a plan to
relocate the nest.
No
No
See
mitigation
The configuration of the conductors on the transmission line poles will
reduce and likely eliminate potential for avian electrocution.
If avian mortality due to collision or electrocution is suspected, the
transmission line will be monitored and preventative measures put into
place, under the guidance of a qualified professional biologist.
No
No
See
mitigation
Potential
Effect
Proposed Mitigation
Construction and Decommissioning
Nest loss
and
disturbance
due to loud
construction
noise
Operation
Avian
mortality
from
transmission
line
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 718 -
American Dipper
American Dippers were observed on Big Silver Creek during the field program. Habitat alteration and
displacement due to disturbance would most likely occur during the construction period; however, a more
stable flow in the diversion reach may also provide more foraging opportunities (i.e., potential positive
environmental effect) during operation (Esler et al. 2007). No other effects on American Dippers are
expected during operation. Instream works are planned over short periods during the dry season;
therefore, with the implementation of other mitigation measures (Table 15-33), residual environmental
effects from construction are not anticipated. Decommissioning will be similar to construction.
Proposed Mitigation
Follow-up
Required?
Potential
Effect
Cumulative
Effect?
Residual Environmental Effects Summary, American Dipper (Big Silver Creek)
Residual
Effect?
Table 15-33
No
No
No
Construction and Decommissioning
Habitat
alteration,
displacement
due to
disturbance
Instream works will be scheduled over short periods during dry season.
Clearing will be restricted to carefully flagged areas within development
footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate ground
cover, shrubs, or trees (once erosion concerns have been addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with Care
(BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along forested and
riparian edges.
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 719 -
Harlequin Duck
One Harlequin Duck was observed on two separate occasions, well upstream of the proposed diversion
reach. Habitat alteration and fragmentation would most likely occur during the construction period, as
some riparian habitat will be permanently removed for facility footprints. Recent research has indicated a
potential positive effect for foraging potential where stream flow is regulated (i.e., during operation) (Esler
et al. 2007). Harlequin Ducks are easily disturbed by human activities along rivers and this would be most
likely during construction. Mitigation measures to locate nesting sites prior to the commencement of any
riparian work during the nesting season are expected to prevent nest abandonment (Table 15-34).
Decommissioning will be similar to construction. Residual environmental effects are not anticipated.
Project operation is not expected to affect Harlequin Ducks.
Cumulative
Effect?
Follow-up
Required?
Residual Environmental Effects Summary, Harlequin Duck (Big Silver Creek)
Residual
Effect?
Table 15-34
Habitat loss
and
fragmentation
Clearing will be restricted to carefully flagged areas within development
footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate ground
cover, shrubs, or trees (once erosion concerns have been addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with Care
(BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along forested and
riparian edges.
No
No
No
Disturbance
due to loud
construction
noise
Before construction within 50 m of suitable Harlequin Duck nesting habitat
during the breeding season (April 1 to August 31), a Harlequin Duck nest
survey will be conducted by a qualified professional in accordance with
current standards and guidelines. If a suspected nest site is located, work will
be delayed in the area until ducklings have left the area.
No
No
No
Potential
Effect
Proposed Mitigation
Construction and Decommissioning
Application for an Environmental Assessment Certificate
Waterpower Projects
Cloudworks
October 2011
- 720 -
Western Screech-owl
Western Screech-owls were not detected within the study area during call playback surveys and no High
or Moderate-suitability habitat overlaps with project footprints. With the implementation of mitigation
(Table 15-35), residual environmental effects are not anticipated. Neither operation nor decommissioning
is expected to affect Western Screech-owls.
Proposed Mitigation
Follow-up
Required?
Potential
Effect
Cumulative
Effect?
Residual Environmental Effects Summary, Western Screech-owl (Big Silver Creek)
Residual
Effect?
Table 15-35
No
No
No
Construction
Habitat loss
and
fragmentation
Clearing will be restricted to carefully flagged areas within development
footprints, except where hazard tree removal is required. If a nest tree is
removed, placement of nest boxes will be considered.
Disturbed sites will be replanted quickly with regionally appropriate ground
cover, shrubs, or trees (once erosion concerns have been addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with Care
(BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along forested and
riparian edges.
Rather than completely removing some large trees near the edge of a
footprint, the possibility of creating snags by “stubbing” will be considered,
providing it is safe to do so.
Mature and old-growth forest will be avoided and existing disturbance
corridors followed, where feasible.
Band-tailed Pigeon
This species was not observed within the study area. Construction activities could remove a small amount
of breeding and foraging habitat for this species. Mitigation measures to reduce the potential for nest
destruction or abandonment (for all migratory birds) will diminish some effects, but habitat loss cannot be
completely avoided. A residual environmental effect is anticipated, but it is not considered significant.
Potential effects associated with operation include interactions with the transmission line. Mitigation
measures, including the removal of perching opportunities near conductors, will avoid or eliminate
residual environmental effects from operation. Decommissioning is not expected to affect Band-tailed
Pigeon. The analysis of residual environmental effects on Band-tailed Pigeon is summarized in
Table 15-36.
Application for an Environmental Assessment Certificate
Waterpower Projects
Table 15-36
Cloudworks
October 2011
- 721 -
Residual Environmental Effects Summary, Band-tailed Pigeon (Big Silver Creek)
Duration/
Frequency
Reversibility
Context
Probability/
Likelihood
Significance
A
L
L
L/I
R
H
M
N
The configuration of the conductors on the transmission line poles will
reduce and likely eliminate potential for avian electrocution.
If avian mortality due to collision or electrocution is suspected, the
transmission line will be monitored and preventative measures put into
place, under the guidance of a qualified professional biologist.
N
Follow-up Required?
Extent
Y
Cumulative Effect?
Magnitude
Clearing will be restricted to carefully flagged areas within
development footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate
ground cover, shrubs, or trees (once erosion concerns have been
addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with
Care (BC MOE 2006a) document will be applied, when appropriate.
Proposed Mitigation
Confidence
Direction
Potential
Effect
Residual Effect?
Residual Environmental Effects
Characterization
H
Y
No
N
No
Construction
Habitat loss
and
fragmentation
Operation
Avian mortality
from
transmission
line
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October 2011
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Migratory Birds
The potential effects of the Project on migratory birds include nest abandonment and direct mortality due
to clearing during construction and for right-of-way maintenance during operation. Other potential effects
associated with operation include interactions with the transmission line. Mitigation measures, including
the removal of perching opportunities near conductors, will avoid or eliminate residual environmental
effects (Table 15-37). Decommissioning is not expected to affect migratory birds.
Cumulative
Effect?
Follow-up
Required?
Residual Environmental Effects Summary, Migratory Birds (Big Silver Creek)
Residual
Effect?
Table 15-37
Vegetation clearing will take place outside of the breeding bird season
(March 15 to August 15) where possible to prevent disturbance of bird
nests
If clearing takes place during the breeding season, qualified
professionals will complete nest surveys prior to construction to
determine if nesting is occurring in the area. If nests are located,
appropriate setback buffers for disturbance will be applied.
No
No
No
Avian
mortality from
transmission
line
The configuration of the conductors on the transmission line poles will
reduce and likely eliminate potential for avian electrocution.
If avian mortality due to collision or electrocution is suspected, the
transmission line will be monitored and preventative measures put into
place, under the guidance of a qualified professional biologist.
No
No
See
mitigation
Nest
abandonment
and direct
mortality due
to clearing
As above for construction.
No
No
No
Potential
Effect
Proposed Mitigation
Construction
Nest
abandonment
and direct
mortality due
to clearing
Operation
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October 2011
Spotted Owl
Spotted Owls have been detected on both sides of Harrison Lake; once on the west side in the early
1990s, and on the east side, several kilometres away from the proposed facilities. The provincial
government has established a SRMZ overlapping Tretheway Creek, but habitat retention objectives there
have been relaxed to accommodate greater habitat retention in other SRMZs in the Fraser Canyon. The
Project will remove <1% (12.6 ha) of High and Moderate suitability habitat in the local study area. In total,
the Big Silver footprints overlap with 41.5 ha of the SRMZ.
Given the linear nature of most of the disturbance and the relatively small amount of forest removal
anticipated within the SRMZ, the residual effect of habitat loss and fragmentation on Spotted Owl is
considered not significant. Spotted Owls have a very low resilience to environmental change at the
landscape level, but can be tolerant of small or even moderate amounts of habitat change within their
territories, providing it does not affect key areas. Much of the habitat affected by the project is currently
not highly suitable and likely won‟t be for a number of years. It is unlikely that Spotted Owls would be
found in close proximity to the Project, as habitat suitability is limiting. SRMZs have been set aside for the
long-term management of the species. It is highly unlikely that the species will re-colonize these areas
without human intervention (i.e., a reintroduction program).
Operation and decommissioning are not expected to affect Spotted Owls. The analysis of residual
environmental effects on Spotted Owl is summarized in Table 15-38.
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Table 15-38
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October 2011
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Residual Environmental Effects Summary, Spotted Owl (Big Silver Creek)
Magnitude
Extent
Duration/
Frequency
Reversibility
Context
Probability/
Likelihood
Significance
Confidence
Cumulative Effect?
Follow-up Required?
Proposed Mitigation
Direction
Potential
Effect
Residual Effect?
Residual Environmental Effects
Characterization
Y
A
L
L
L/I
I
L
M
N
M
Y
No
Construction
Habitat loss
and
fragmentation
Clearing will be restricted to carefully flagged areas within
development footprints, except where hazard tree removal is
required.
Disturbed sites will be replanted quickly with regionally appropriate
ground cover, shrubs, or trees (once erosion concerns have been
addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with
Care (BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along
forested and riparian edges.
Rather than completely removing some large trees near the edge of
a footprint, the possibility of creating snags by “stubbing” will be
considered, providing it is safe to do so.
Mature and old-growth forest will be avoided and existing disturbance
corridors followed, where feasible.
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October 2011
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Columbian Black-tailed Deer
Columbian black-tailed deer may incur greater mortality from hunting and road traffic due to
improvements in the road conditions, but mitigation measures applied during construction, operation, and
decommissioning are expected to prevent any residual environmental effects (Table 15-39). The winter
range polygons within the local study area will not be affected by the Project.
Cumulative
Effect?
Follow-up
Required?
Residual Environmental Effects Summary, Columbian Black-tailed Deer (Big Silver
Creek)
Residual
Effect?
Table 15-39
Increased
hunting
mortality
Crews will be prohibited from hunting in the area.
Temporary roads and staging/spoil areas will be deactivated and planted with
appropriate vegetation when no longer needed.
Road deactivation will include measures designed to prevent ATV access.
No
No
No
Increased
road
mortality
Safe speed limits along access roads will be imposed.
Contractors/crews will be encouraged to use as few vehicles as possible to
access work site.
Wildlife observations will be recorded; Environmental Monitor will inform drivers
of road sections frequented by wildlife.
Temporary roads will be deactivated and re-planted with appropriate vegetation
when no longer needed.
Revegetation will use unpalatable regionally approved vegetation when replanting cleared roadsides where feasible, to discourage foraging.
No
No
No
Potential
Effect
Proposed Mitigation
Construction, Operation, and Decommissioning
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October 2011
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Grizzly Bear
Due to the amount of existing anthropogenic disturbance, resident grizzly bears are unlikely to be present
in the Big Silver Creek study area. Transient grizzlies might use the area occasionally but no resident
bears are known in these study areas based on DNA studies (C. Apps pers. comm., June 2008). Minimal
amounts of High to Moderate-rated foraging habitat (Class 1-3) overlap with the proposed facilities (5.8
ha of fall habitat, 2.6 ha of summer habitat, and <1 ha of spring habitat), and the transmission line may
improve berry/forb forage opportunities in areas where suitable habitat is not currently present.
Road densities will not increase measurably and the areas that are being disturbed for the facilities are
designed to overlap previously-disturbed areas and other linear features on the landscape (i.e., existing
roads). Potential bear interactions are still a concern, especially with black bears, and mitigation methods
will be applied to prevent any residual effects associated with problem animal mortality (Table 15-40).
Follow-up
Required?
Proposed Mitigation
Cumulative
Effect?
Potential
Effect
Residual Environmental Effects Summary, Grizzly and Black Bears (Big Silver
Creek)
Residual
Effect?
Table 15-40
No
No
No
Construction, Operation, and Decommissioning
Problem
animal
mortality
Crews will participate in an appropriate wildlife awareness training program, and
be instructed to refrain from feeding wildlife.
Food scraps and garbage from construction sites will be removed or stored in
bear-proof containers for proper disposal.
Work crews will be prohibited from hunting and cleaning game in the Project
area.
Nuisance bears will be reported to a Conservation Officer, who would assist in
determining appropriate measures.
Human-Bear Conflict Management measures will be developed and included in
the CEMP to provide clear procedures for handling bears that wander onto work
sites.
All road kill will be promptly moved from roadways to prevent scavenging wildlife
(including bears) from being attracted to the roads.
Revegetation will use unpalatable regionally approved (appropriate) vegetation
when re-planting cleared roadsides where feasible, to discourage foraging.
Wildlife observations will be recorded; Environmental Monitor will inform drivers
of road sections frequented by wildlife.
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Waterpower Projects
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October 2011
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Pacific Sideband
There is limited information available about this species‟ biology. It has been observed in a number of
habitat types in BC, including clear-cuts. The species was not observed within the study area during field
work. Habitat loss / degradation and associated direct mortality during construction are likely the biggest
concerns. However, with the implementation of mitigation measures during construction and operation
(Table 15-41), and likely limited amount of suitable habitat that could be affected, residual effects are not
anticipated. Decommissioning activities would be similar to construction. Effects during operation would
be limited to use of herbicides. With appropriate herbicide use procedures outlined in the CEMP, no
residual environmental effects are expected.
Cumulative
Effect?
Follow-up
Required?
Residual Environmental Effects Summary, Pacific Sideband (Big Silver Creek)
Residual
Effect?
Table 15-41
Clearing will be restricted to carefully flagged areas within development
footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate ground
cover, shrubs, or trees (once erosion concerns have been addressed).
„Soft edges‟ will be created along right-of-way and access roads by
maintaining shrub species along the forest edge. Relevant portions of
Section 3 (Site Development and Management) of the Develop with Care
(BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along forested
and riparian edges.
No
No
No
CEMP will include pest management plan with guidance for herbicide use
in areas where species-at-risk may occur.
No
No
No
Potential
Effect
Proposed Mitigation
Construction and Decommissioning
Habitat loss and
fragmentation
Operation
Habitat
alteration,
mortality due to
herbicide use
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October 2011
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Black Petaltail
While the species was not found in the Big Silver study area, it was observed nearby in the Tretheway
study area. The potential for habitat loss and degradation is likely the greatest concern during
construction, but potential reproducing sites that can be readily mapped will be avoided. After the
implementation of mitigation measures during construction and operation (Table 15-42), and given the
likely limited amount of suitable habitat that could be affected, residual effects are not anticipated.
Decommissioning activities would be similar to construction. Effects during operation would be limited to
use of herbicides. With appropriate herbicide use procedures outlined in the CEMP, no residual
environmental effects are expected.
Cumulative
Effect?
Follow-up
Required?
Residual Environmental Effects Summary, Black Petaltail (Big Silver Creek)
Residual
Effect?
Table 15-42
Habitat loss and
fragmentation
Clearing will be restricted to carefully flagged areas within development
footprints, except where hazard tree removal is required.
Sensitive ecosystems (wetlands) will be avoided during final project design
to the extent feasible.
Areas to be avoided will be identified and fenced off prior to construction
activities, if located adjacent to the Project footprint.
No
No
No
Introduction of
silt and other
harmful
substances
BMPs will be followed for in-stream works.
CEMP will include sections on managing construction waste, spill
prevention, and emergency response.
Equipment will be checked to ensure systems are free of leaks and in good
condition.
All machines working near water will have spill kit, trained operators.
Erosion and sedimentation plan will be in place.
No
No
No
CEMP will include pest management plan with guidance for herbicide use
in areas where species-at-risk may occur.
No
No
No
Potential
Effect
Proposed Mitigation
Construction and Decommissioning
Operation
Habitat
alteration,
mortality due to
herbicide use
Rare Plants
Twenty plants of the Rorippa species, potentially new to science, were found scattered on a lakeshore
beach, along with the Red-listed species Berula erecta and Fontinalis hypnoides. All were found
approximately 60 m away from the proposed transmission line corridor on the west side of Harrison Lake.
This lakeshore beach will be avoided during construction and with the implementation of mitigation
measures during construction and operation, residual environmental effects are not anticipated
(Table 15-43). Decommissioning activities would be similar to construction.
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October 2011
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Rare Ecological Communities
Approximately 1.7% or 29.6 ha of Moderate and High-ranked potential habitat could be affected by the
Project, although no specific rare ecological communities were verified during field studies. Rare plants
and sensitive habitats were documented, but these are not expected to be affected by the Project. Habitat
alteration is likely the greatest threat to these sites, through changes in the composition of the plant
community and the potential for invasive plants to become established. The more sensitive habitats,
especially where rare plants were located, do not overlap any Project footprint. After the implementation
of mitigation measures during construction and operation, residual effects are not anticipated
(Table 15-43). Decommissioning activities would be similar to construction.
Proposed Mitigation
Follow-up
Required?
Potential
Effect
Cumulative
Effect?
Residual Environmental Effects Summary, Rare Plants and Rare Ecological
Communities (Big Silver Creek)
Residual
Effect?
Table 15-43
No
No
See
mitigation
Construction and Decommissioning
Habitat loss
and direct
mortality
Clearing will be restricted to carefully flagged areas within development
footprints, except where hazard tree removal is required.
If facility locations (including access roads, transmission lines, spoil
areas, and laydown sites) change during the final design phase, new
areas will be checked for the presence of rare plants.
Rare plant communities and sensitive ecosystems known or identified
during final design will be avoided and fenced off prior to construction
activities, where located close to any Project footprint.
Disturbance to or in special habitats (e.g., alluvial fans, lake beaches,
non-forested wetlands, rock outcrops, cliffs) will be avoided to extent
feasible.
Natural drainage patterns will be maintained or restored.
Soil rehabilitation and revegetation monitoring will be conducted.
Follow-up
Required?
Proposed Mitigation
Cumulative
Effect?
Potential
Effect
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October 2011
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Residual
Effect?
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Waterpower Projects
No
No
Yes; see
mitigation
No
No
See
mitigation
Preventing the establishment of invasive species is by far the most
important step in mitigating the risk for introduction. The government of
Canada currently employs inspection techniques at ports and border
crossings to reduce the risk of importing many invasive insect species,
and federal and provincial governments have strategies to address
other points of introduction or spread on regional levels (Government of
Canada 2004)
Rare plant communities and sensitive ecosystems known or identified
during final design will be avoided and fenced off prior to construction
activities, where located close to any Project footprint.
Disturbed sites will be revegetated as soon as possible after
construction with regionally appropriate ground cover, shrubs, or trees
(once erosion concerns have been addressed) and monitored for
revegetation success (see Section 15.2.4.2).
Invasive
species
Introduction
of silt and
other
harmful
substances
Prior to any land clearing or soil disturbance activities, a qualified
individual familiar with invasive species identification will conduct a site
survey to locate any occurrences of invasive species in areas
potentially affected by the Project. Known occurrences of invasive
species will be avoided in final facility siting/routing if feasible. Known
occurrences of invasive species in or adjacent to work sites will be
flagged in the field prior to construction.
All construction vehicles and equipment will be thoroughly washed,
paying special attention to undercarriages, wheel wells, tire treads, and
tracks where mud, insect larvae, and seeds may be lodged, before their
arrival to any work site or relocation from any site where invasive plants
are already established. Washing areas will be located an appropriate
distance away from any waterbody and riparian areas and run-off will
be directed away from them.
Domestic animals will be kept out of the work site whenever possible.
Monitoring for invasive plants at any disturbance/reclaimed site will
continue until revegetated sites are well established. Environmental
Monitor will record presence of any newly established invasive species
determined to be present because of construction. A professional
biologist will assess any such new populations and develop an invasive
plant removal strategy.
CEMP will include sections on managing construction waste, spill
prevention, and emergency response.
Maintenance and refuelling will be conducted at an approved distance
away from watercourses.
Equipment will be checked to ensure systems are free of leaks and in
good condition.
All machines working near water will have spill kit, trained operators.
Erosion and sedimentation plan will be in place.
Clearing, grubbing will be minimized, especially in wet weather. Natural
vegetation cover, woody debris, and organic matter will be retained
when possible.
Disturbed areas will be revegetated as soon as possible with regionally
appropriate species.
Soil rehabilitation monitoring will inform recommendations for any
follow-up soil rehabilitation activities that may be necessary to ensure
soil rehabilitation success.
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October 2011
Cumulative
Effect?
Follow-up
Required?
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Residual
Effect?
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Waterpower Projects
Mortality
due to
herbicide
use
CEMP will include pest management plan with guidance for herbicide
use in areas where rare plants may occur.
No
No
No
Invasive
species
As above for construction and decommissioning.
OPP will specify measures to prevent introduction and/or spread of
invasive species for ongoing maintenance activities, such as control of
vegetation. These measures will be informed by a review of vegetation
management plans developed for transmission line corridors by BC
Hydro, including Integrated Vegetation Management Plan for
Distribution Line Corridors (BC Hydro, 2005), Pest Management Plan
for Management of Vegetation at BC Hydro Facilities (BC Hydro, 2006),
and Approved Work Practices for Managing Riparian Vegetation (BC
Hydro et al., 2003).
Slow-growing later-successional plants may be used to prevent
invasive plant spread and reduce pruning and maintenance
requirement.
No
No
Yes; see
mitigation
Potential
Effect
Proposed Mitigation
Operation
Follow-up and Monitoring
The need for follow-up and monitoring is summarized in the residual effects assessment summary tables
in Section 15.2.4.1 above and addressed in Section 21.
Cumulative Effects
The cumulative effects assessment (CEA) study area encompasses those areas within which the residual
environmental effects of the Project (described in Section 15.2.4.1 above) may or are likely to interact
cumulatively with the effects of other past, present, and future projects and activities (Figure 4-1).
Because the Shovel Creek and Tretheway Creek Waterpower Projects will be located within the same
CEA study area as the Big Silver Creek Waterpower Project, their potential residual environmental effects
are considered together with those of the Big Silver Creek Waterpower Project in the assessment below.
Other projects and activities that have occurred, are occurring, or will occur within the CEA study area,
and that are particularly relevant to the Big Silver CEA, are described below. (Greater detail is provided in
Section 7.2 of the Keystone EA in Appendix K of this Application.)
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Past Projects and Activities
Forestry has had the most impact on the landscape compared to the history of mining, fur trapping,
settlement, and fishing in the area.
Prior to 1960, 6,622 ha of timber had been harvested in the Tretheway, Shovel, and Big Silver CEA study
area. This may be an underestimate, as logging regulations and records were not well kept before the
mechanized logging era. Between 1960 and 1990, 21,466 ha of timber were removed in the Tretheway,
Shovel, and Big Silver CEA study area. Between 1990 and 2002, 516 ha of timber were removed in the
Tretheway, Shovel, and Big Silver CEA study area.
Cumulatively, 29% of the treed area in the
Tretheway, Shovel, and Big Silver CEA study area had been removed by 2002.
Historical forestry (from as early as the 1940s) and associated logging camps are likely a major reason
that wildlife and plants that depend on un-fragmented habitat or large old growth habitat features are rare
on the landscape. The constructions of the railway, Highway 1, and numerous logging roads in the area
have further fragmented the habitat and have led to additional resource extraction and access for
recreational use. The recent (last 20 years) increase in recreational uses (such as hiking, camping,
boating, and off-road vehicle use) around the Harrison Lake area has also contributed to the disturbance
and displacement of wildlife and plant species in the area.
Current Projects and Activities
Almost all the current activities within the Big Silver CEA study area create disturbance and/or
displacement of wildlife. The amount of human use that occurs, and the associated mortality risk, is likely
the main reason grizzly bears are threatened within the Stein-Nahatlatch and Garibaldi-Pitt GBPUs. Most
human activities are concentrated in the summer months, although recreational activities in the area are
expected from May to October (or longer) depending on weather and road conditions.
Recreation
The Big Silver LU receives low to moderate levels of public recreation due to its location (George et al.
2005b). Recreation activities involve hiking, sightseeing, fishing, hunting, and 4x4 driving. Winter use is
restricted by road deactivation, although some snowmobiling occurs in the area (George et al. 2005b).
East Harrison LU receives moderate to heavy public recreation use from spring to fall (George et al.
2005c). Winter recreation off the main East Harrison FSR is restricted by seasonal road deactivations
(George et al. 2005c). The Tretheway LU receives low recreation due to the rugged road and remote
location (George et al. 2005a). There are few recreation sites in the Tretheway LU so activities are mostly
limited to 4-wheel drive and ATV use, hunting and wildlife viewing (George et al. 2005a). The Harrison
Lake area is heavily used by ATV and dirt bike riders. Erosion/vegetation damage (especially in riparian
areas), wildlife disturbance, and potential contamination from fuel or fluids leaks may occur in areas of
concentrated use.
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Boating
Harrison Lake is used mostly by powerboats but also by canoeists/kayakers in sheltered areas. Harrison
Yacht Club operates the Long Island Bay recreation site and has docks available for larger boats. Small
boats are permitted on Weaver Lake and Twenty Mile Bay. Non-motorized boats are allowed on Wood
Lake. There is small boat activity at Sunrise Lake. In Sasquatch Provincial Park, boating is permitted on
Deer and Hicks Lakes but motorboats are restricted on Hicks Lake. Trout Lake is the smallest lake in the
park and is the easiest to paddle. Smaller boats are permitted at Rainbow Falls.
The lower 3 km of Cogburn Creek is rated as a Class 3 or 4 route and is used by whitewater paddlers.
There is also an expert section of Cogburn Creek that is used by whitewater paddlers (Schwab 2007).
The lower portion of Big Silver Creek is suitable for novice paddlers with a couple of Class 2 features.
Access is west of the junction of Harrison East/Clear Creek roads and the take-out is south of the Silver
River logging camp on Harrison Lake (Mussio et al. 2003). The middle section of Big Silver Creek is rated
as intermediate/advanced paddling, and several sections upstream are paddled by advanced/expert
paddlers (Schwab 2007).
Recreational boating can have effects associated with the introduction of harmful substances if there are
fuel leaks or spills; disturbance to nesting birds if there are loud noises or boaters get too close to active
nests; invasive species; and problem animal mortality.
If boating is associated with camping then
additional impacts can occur (see below).
Cabins and Camping
Weekend campers frequent both sides of Harrison Lake during the summer months, gaining access to
camping areas by boat and vehicle (along the various logging roads). There are at least 19 recreational
sites used for camping (and other motorized and non-motorized recreational activities) in the
Tretheway/Big Silver/Shovel CEA study area. Some are open year-round, while others are seasonally
used. A common effect associated with camping is the accumulation of garbage and poor containment of
food and food scraps. This can often lead to problem animal mortality, especially bears that are attracted
to the areas. Local habitat degradation (notably cutting for firewood), the introduction of harmful
chemicals, and the introduction of invasive species are also a concern.
Additional Recreational Opportunities
Additional recreational opportunities in the CEA study area include the Hemlock Valley Ski Resort,
located in the West Harrison LU, which has 121 ha of skiable terrain and 13 km of cross-country trails,
and accommodates about 1,500 to 2,000 day guests per day during the ski season.
Big Boar Outfitters has a guiding territory that includes the Chehalis, East Harrison, West Harrison, Big
Silver, and Tretheway LUs. Approximately 35 hunters are guided during April to mid-June to hunt in the
Chehalis to the Pemberton area (A. Dougan pers. comm.). Access is primarily by truck, ATV, or by foot.
Approximately 30-50 black bears are harvested every year during the two to three month period (A.
Dougan pers. comm.).
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Power Generation and Transmission
Lakeside Pacific Forest Products Ltd. has one work camp at Cogburn Creek that produces power from
five separate diversion points at Graham, Derek, Ronald, North Ronald, and Ivan Creeks. A maximum
diversion amount of 1,500 gallons per day for work camps and 2 cubic feet per second for power
production is licenced on the creeks. There are residential water licences registered to Jenner Creek near
Sasquatch Provincial Park, to Connor Creek, and to Drift Bold Creek (near Morris Creek).
The Lower Lillooet Project consists of three run-of-river projects on Douglas, Lower Fire, and Stokke
Creeks. Stokke is the only project that falls within the CEA study area. It has a 22 MW capacity and is
connected to the other Lower Lillooet Projects by a 138 kV transmission line.
The Upper Harrison Water Power Project, currently under construction, consists of three run-of-river
projects, though only one (Tipella) occurs within the CEA study area. The Tipella Creek project footprint
removed approximately 18 ha of suitable habitat for Western Screech-owl, Spotted Owl, grizzly bear
spring and fall feeding habitat, and deer feeding habitat (Hamilton and Associates 2006). The
transmission line at Tipella parallels a 360 kV BC Hydro transmission line (3L2), which runs along the
west side of Harrison Lake to an interconnection site near Agassiz. This 360 kV line provides
opportunities for the introduction and spread of invasive plants within the study area, although BC Hydro
does work with the various plant councils to monitor and remove some of the more aggressive noxious
weeds.
Forestry
Forestry has the most direct and largest effect on habitat removal and fragmentation in the area, with an
AAC for the Fraser TSA of 1.27 million cubic metres a year (Pederson 2004).
Within the Big Silver LU, 18,819 ha of forest are within the THLB (George et al. 2005b). Forty-two (42)
percent of the forested land base in the Big Silver LU is not over sixty years of age (George et al. 2005b).
Forty-three (43) percent of the forested land base within the East Harrison LU is aged zero to sixty years
old (George et al. 2005c). Within the West Harrison LU, 19,563 ha of Crown forest are within the THLB
(George et al. 2005d). Sixty-one (61) percent of the forested landbase in the West Harrison LU is not
more than sixty years old (George et al. 2005d). Within the Crown forested land base for the Tretheway
LU, 7,392 ha are within the THLB (George et al. 2005a).
Forestry operations may have environmental effects similar to those of the Big Silver Creek Waterpower
Project. Forestry activities follow a number of guidelines to address management for species that are rare
on the landscape or are of regional concern.
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Settlements
The Hemlock Valley settlement (on the west side of Harrison Lake) includes 26 full-time residents and
800-1000 seasonal residents during the winter. It is a resort town but has access to fire services and
underground utilities. This settlement will interact with local wildlife.
Issues associated with habitat
fragmentation, introduction of harmful substances, nest loss, invasive species, and animal mortality are all
of concern.
Transportation and Infrastructure
The West Harrison FSR runs along the west side of Harrison Lake and the East Harrison FSR runs along
the east side of Harrison Lake. Both are heavily used for recreational access. The extensive road network
provides opportunities for the introduction and spread of invasive plants. Forestry roads fragment habitat
throughout the study area and continued use of these by motorcycles, ATVs, and other off-road vehicles
can result in soil erosion and minor chemical spills (fuel and lubrication leaks). Roads also allow access
for illegal hunting and risk of mortality due to vehicular collision.
First Nations Use
The Big Silver LU is located within the asserted traditional territory of the Chehalis Band and the Sto:lo,
In-SHUCK-ch, and Nlaka‟pamux First Nations (George et al. 2005b). The East Harrison LU is located
within the asserted traditional territories of the Sto:lo, Chehalis, and Yale First Nations (George et al.
2005c).
The Chehalis Indian Band has indicated that two transformer sites and a village are located between the
Big Silver transmission line and Doctors Point (Golder 2009). Shovel Creek and Big Silver Creek are both
traditional trap line areas and travel corridors for the In-SHUCK-ch Nation (Golder 2009). The Big Silver
transmission line crosses through areas that have been or are used for fishing, habitation, spiritual sites,
trap lines, travel corridors, gathering areas, hunting areas, and fishing areas (Golder 2009). The Big Silver
Creek transmission line route was used by the Sto:lo First Nation for hunting and has cultural landscape
features, potential archaeological sites, and trails (Golder 2009).
The Tretheway LU is located within the asserted traditional territories of the Sto:lo, Chehalis, and InSHUCK-Ch First Nations (George et al. 2005a).
The Chehalis Indian Band has indicated that, between Tretheway Creek and Tipella Creek, there may be
a village or transformer site and several camps along the shoreline (Golder 2009). The In-SHUCK-ch
Nation has indicated that Tretheway Creek is a traditional place for fishing, trap lines, hunting, and
gathering (Golder 2009). The Sto:lo First Nation traditional used Tretheway Creek for fishing and hunting
(Golder 2009).
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Future or Proposed Projects and Activities
As population increases, the land around the Lower Mainland will incur more urban and suburban sprawl,
and transportation corridors will expand (BC MOE 2007b). This will likely result in increased pressure for
industrial and residential development and increased recreational use in the surrounding areas. There will
likely be greater conflicts between industrial needs and the preservation of the viewshed from the south
end of the lake.
Much of the forested area has been previously logged, although logging continues in much of the area,
albeit scaled down from a decade or so ago. Forestry will continue to occur but its intensity, location, and
frequency will depend on timber prices, access, technology, and constraints.
Sea to Sea Jeep Tours has proposed using the East and West Harrison FSR to run recreational tours in
the Harrison Lake area (ILMB 2009). An application to ILMB was submitted in 2003 and is currently under
review (ILMB 2009).
Tamihi Logging Company has applied to use an area at the near the confluence of Big Silver Creek and
Harrison Lake for log handling and storage (ILMB 2009). There is an application to the ILMB filed May 7,
2009 by Southview Sorting Ltd. to establish a 14 ha sand and gravel quarry site near the confluence of
Bear and Cogburn Creek (ILMB 2009). E.J. Fryer submitted an application to the ILMB to quarry rip rap
from a nine ha area north of Rainbow Falls on April 7, 2008, which is currently under review (ILMB 2009).
The status of these applications remains uncertain.
There are a number of proponents that have applied for water licences to produce power on creeks on
both sides of Harrison Lake. However, none of these projects have approvals to proceed or Electricity
Purchase Agreements with BC Hydro, and were therefore not included in the CEA.
The proposed BC Hydro Interior-Lower Mainland (ILM) Transmission Project has received an
Environmental Assessment Certificate. It proposes a new 250 km 500 kV transmission line from the
Merritt area to Coquitlam BC, with the majority of the route running along existing rights-of-way,
paralleling BC Hydro‟s 500 kV transmission line (5L82) within the CEA study area. The ILM project will
remove forested habitat where it passes through the study area, including some suitable habitat for
Spotted Owl and Northern Goshawk. The ILM project will use the existing 500 kV transmission right-ofway as much as possible, thereby minimizing potential disturbance to new areas. However, the current
right-of-way will become wider with the addition of the new line, potentially acting as a barrier to
movement and dispersal for some species. Project construction is expected to start in the near future,
with right-of-way preparation (e.g., tree falling) likely being the biggest disturbance.
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Leader Mining International Ltd. has conducted pre-drilling tests and a feasibility study for a magnesium
project located on the west slopes of Talc Creek near its headwaters. The deposit is of large size with
high magnesium grade, low impurity, favourable metallurgy, and proximity to infrastructure. The project
will have a production capacity of greater than 75,000 tonnes per year of mineral ore. The magnesium
processing plant would be located between Mahood and Ruby Creeks. The project will require
groundwater extraction at a rate greater than 75 litres per second. The project is at the pre-application
stage with the BC Environmental Assessment Office; the proponent has requested to hold this project
until after 2010. One of the major limiting factors of the proposed magnesium mine was obtaining power
to run the onsite processing plant. It is uncertain if the project will re-enter the assessment process.
As noted earlier, because the Shovel Creek and Tretheway Creek Waterpower Projects will be located
within the same CEA study area as the Big Silver Creek Waterpower Project, their potential residual
environmental effects are considered together with those of the Big Silver Creek Waterpower Project in
the assessment below.
Determination of Cumulative Environmental Effects
Other types of projects and activities likely to interact with the residual environmental effects of the Big
Silver Creek Waterpower Project are summarized in Table 15-44.
Pacific tailed frog
Introduction of silt and other harmful substances






First Nations Use

Transportation
Removal of suitable habitat
Settlements
Residual Environmental Effect of the Project
Forestry
Valued
Environmental
Component
Power Generation
and Transmission
Assessment of Potential Interactions between Other Projects and Activities and
Project Residual Environmental Effects within the Big Silver CEA Study Area
Recreation
Table 15-44

Direct mortality
Northern Goshawk
Removal of suitable nesting habitat


Spotted Owl
Removal of suitable nesting habitat


Band-tailed Pigeon
Removal of suitable habitat



The specific projects and activities within these general categories that would most likely interact with the
residual environmental effects of the Big Silver Creek Waterpower Project include forestry (past, present,
and future) and the ILM transmission line (future). While some recreational activities (boating and
camping) likely are the cause for some incidences of introduction of harmful substances to the
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environment, they would mostly occur in habitats removed from tailed frogs. The ILM transmission line
and forestry operations will remove suitable habitat for a number of species but mitigation measures and
work practices are in place to avoid impacts when working around riparian areas, thereby minimizing
some of the potential for adverse effects to tailed frogs.
Pacific Tailed Frog
Cumulatively, the effects on Pacific tailed frog within the Big Silver CEA study area include direct habitat
loss and fragmentation and possible mortality due to multiple land uses on the environment. Past and
continuing effects associated with logging (including transmission line clearing) and off-road vehicle use
include stream exposure, siltation of the stream, and habitat loss. In addition, run-off from roads and
improper culvert installation can reduce movement and stream productivity.
While these past and present activities have likely played a significant part on the suspected decline of
the species, recent initiatives (Riparian Areas Regulation and riparian setbacks for fisheries requirements)
have offered greater protection for riparian areas. Additional protection has come through the
establishment of parks, management areas, and buffered no-work zones around riparian areas. Due to
past activities and continuing possible effects, the cumulative effect without the Project is considered
significant.
As described previously, the Big Silver Creek Waterpower Project will remove some habitat within the
diversion reach and may also result in mortality of some tadpoles during dewatering for construction.
Some riparian habitat will be permanently removed for construction of the facilities. However, temporarily
disturbed habitats will be restored, reducing the habitat loss. The potential residual environmental effects
of the Shovel Creek and Tretheway Creek Waterpower Projects are similar. Given the very limited scale
of the Projects‟ residual environmental effects in comparison to the extant effects of other projects and
activities, the contribution of these Projects to cumulative effects is considered to be not significant, and
the Projects are not expected to substantively alter the cumulative effects already observed.
Table 15-45 summarizes the assessment of potential cumulative environmental effects on Pacific tailed
frog.
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Table 15-45
Evaluation
Criteria
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Pacific Tailed Frog Cumulative Effects Analysis for Big Silver CEA Study Area
Cumulative
Effects without
Tretheway, Big
Silver, and
Shovel Projects
Tretheway, Big
Silver, and Shovel
Projects
Contribution to
Cumulative Effects
Comments
Amount of habitat removal due to the Project is very
low compared to the amount that is currently
available in the CEA study area. Except for work in
the creek itself, much of the development will occur
alongside existing disturbance (roads and cut-blocks)
and through areas that will be disturbed again in the
future by other projects and activities.
Magnitude
Moderate
Negligible
Geographic
Extent
Regional
Sub-local
Duration and
Frequency
Short-term and
Frequent
Long-term and
Infrequent
The removal of some suitable habitat will last the life
of the Project, which is longer than for timber harvest,
as the area is allowed to regenerate. The removal of
suitable habitat will occur once for the Project.
Reversibility
Short-term to
Long-term
Long-term
Some Project residual effects will last until the Project
is decommissioned.
Low
Low
The species is not very resilient to habitat changes.
Significance
Significant
Not significant
Past activities likely had a significant cumulative
effect, although new initiatives are providing species
protection. The contribution of the Project will not be
significant.
Confidence
High
High
Context
Northern Goshawk
Cumulatively, effects on Northern Goshawk in the Big Silver CEA study area include direct habitat loss
and fragmentation due to multiple land uses on the environment. The largest impact on Northern
Goshawk nesting habitat is logging. Nearly one third of the CEA boundary has been logged within the
past 100 years, and much of this historically logged landscape will be harvested again. Other factors
affecting habitat loss include various linear features such as FSRs and transmission lines that fragment
the area. These other land uses, mainly forestry, have already had a significant adverse effect on suitable
Northern Goshawk habitat.
As described previously, the Big Silver Creek Waterpower Project will remove relatively small amounts of
suitable habitat during construction of the proposed facilities. Project facilities, notably the proposed
transmission line, follow other linear corridors, where possible, and overlap previously disturbed areas
that are likely to be disturbed (harvested) again in the future. The transmission line alignment avoids a
number of constrained areas. Much of the forested habitat along the proposed transmission line is
vulnerable to future harvesting regardless if the Project goes ahead. The potential residual environmental
effects of the Shovel Creek and Tretheway Creek Waterpower Projects are similar. The contribution of
these Projects to cumulative effects is not considered significant, especially in comparison to the extant
effects of other projects and activities, and the Projects are not expected to substantively alter the
cumulative effects already observed.
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Management recommendations for the Red-listed sub-species in the Chilliwack Forest District assume
the sub-species occurs in the Project area based on the biogeoclimatic zones that are present, but its
occurrence has not been confirmed. If the Red-listed sub-species is confirmed to occur in the Project
area, additional future management measures may be imposed. Local Spotted Owl habitat management
(and likely DWR management) may be sufficient to manage goshawks in the region, as these species
appear to share many similar habitat attributes.
Table 15-46 summarizes the assessment of potential cumulative environmental effects on Northern
Goshawk.
Table 15-46
Evaluation
Criteria
Northern Goshawk Cumulative Effects Analysis for Big Silver CEA Study Area
Cumulative
Effects without
Tretheway, Big
Silver, and
Shovel Projects
Tretheway, Big
Silver, and Shovel
Projects
Contribution to
Cumulative Effects
Comments
Magnitude
High
Low
Amount of habitat removal due to the Projects is low
compared to the amount that is currently removed in
the CEA study area. Much of the development will
occur alongside existing disturbance (roads and cutblocks) and through areas that will be disturbed again
in the future.
Geographic
Extent
Regional
Regional
The removal of habitat by the three Projects
combined may affect Northern Goshawks regionally.
Duration and
Frequency
Long-term and
Frequent
Long-term and
Infrequent
Reversibility
Long-term
Long-term
Low
Low
Context
The removal of suitable nesting habitat will last the
life of the Projects, which is longer than for timber
harvest, as the area is allowed to regenerate. The
Projects will remove suitable habitat once.
This species has low resilience to environmental
change.
Significance
Significant
Not significant
Other land uses, mainly forestry, have already had a
significant impact on suitable Northern Goshawk
habitat. The contribution of the Project to cumulative
effects will not be significant.
Confidence
Moderate
Moderate
The occurrence of the Red-listed sub-species within
the study area has not been confirmed.
Spotted Owl
The Spotted Owl population has been severely diminished due to timber harvest and other land clearing
activities, inter-specific competition, and habitat fragmentation and alteration from other land uses. Almost
one third of the CEA study area has been logged within the past 100 years and much of this historically
logged landscape will be harvested again. To address the existing cumulative effect, the Province has
created SRMZs to manage the species.
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Project facilities, notably the proposed transmission line, follow existing linear corridors where possible,
and overlap previously disturbed areas that are likely to be disturbed (harvested) again in the future. A
number of constrained areas (including the Sasquatch SRMZ) were avoided during transmission line
alignment. The Tretheway Creek and Big Silver Creek Waterpower Projects will together remove 10.1 ha
of High-rated habitat and 6.6 ha of Moderate-rated habitat. About 40 ha, most of which is currently
unsuitable as breeding habitat, will be permanently removed within the SRMZ. However, while the SMRZ
in the Tretheway area may become important for the Spotted Owl in the future, its purpose in the new
SOMP is in fact to allow for more timber harvesting possibilities as a trade-off for greater habitat
protection for areas adjacent to the Fraser River (BC MOE 2009). The area affected accounts for about
one percent of one LTAC and is not considered to be significant (particularly when compared to the
existing disturbance on the landscape). Given the very limited scale of the Projects‟ residual
environmental effects in comparison to the extant effects of other projects and activities, the contribution
of these Projects to cumulative effects is considered to be not significant, and the Projects are not
expected to substantively alter the cumulative effects already observed.
Table 15-47 summarizes the assessment of cumulative environmental effects on Spotted Owl.
Table 15-47
Evaluation
Criteria
Magnitude
Geographic
Extent
Spotted Owl Cumulative Effects Analysis for the Big Silver CEA Study Area
Cumulative
Effects
without
Tretheway
and Big Silver
Projects
High
Regional
Tretheway
and Big Silver
Projects
Contribution
to Cumulative
Effects
Negligible
Amount of habitat removal due to the Tretheway Creek and
Big Silver Creek Waterpower Projects is very low compared
to the amount that is currently removed in the CEA study
area. Much of the development will occur alongside existing
disturbance (roads and cut-blocks) and through areas that
will be disturbed again in the future.
Regional
Given the length of the transmission line and footprints on
both sides of Harrison Lake the removal of habitat by the
Projects could affect Spotted Owls on a regional extent (over
the life of the project).
The removal of suitable nesting habitat will last the life of the
Projects, which is longer than for timber harvest, as
harvested areas are allowed to regenerate to forest (but not,
perhaps, to old-growth). The Projects will remove suitable
habitat once.
Duration and
Frequency
Long-term and
Frequent
Long-term and
Infrequent
Reversibility
Long-term
Long-term
Low
Low
Context
Comments
Significance
Significant
Not significant
Confidence
High
High
This species has low resilience to environmental change.
Other land uses, mainly forestry, have already had a
significant impact on suitable habitat for the species. The
contribution of the Projects to cumulative effects will not be
significant.
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Band-tailed Pigeon
Cumulatively, effects on Band-tailed Pigeons within the Big Silver CEA study area include direct habitat
loss and fragmentation due to multiple land uses. Almost one third of the CEA study area has been
logged within the past 100 years and much of this historically logged landscape will be harvested again.
Breeding Bird Survey data indicate that the range of the species in BC may be expanding; however, the
total number of birds has been decreasing since 1966 at an average annual rate of 2.8% across North
America (Keppie and Braun 2000; BC CDC 2008). Loss and degradation of suitable breeding habitat is
considered a significant threat to the Band-tailed Pigeon (Braun 1994). Within the study area, historic
logging has likely resulted in an increase in present-day habitat availability, given that stands harvested
40-60 years ago are currently at the most suitable age for Band-tailed Pigeon.
The proposed transmission line could offer good forage opportunities as the openings will promote the
growth of fruit and flower-producing shrubs. Given this potentially positive effect, together with the limited
scale of the Projects‟ residual environmental effects in comparison to the extant and ongoing effects of
other projects and activities, the contribution of these Projects to cumulative effects is considered to be
not significant, and the Projects are not expected to substantively alter the cumulative effects already
observed. Forestry will continue to have a larger effect on the species.
Table 15-48 summarizes the assessment of cumulative environmental effects on Band-tailed Pigeon.
Table 15-48
Band-tailed Pigeon Cumulative Effects Analysis for the Big Silver CEA Study Area
Cumulative
Effects without
Tretheway, Big
Silver, and
Shovel
Projects
Tretheway, Big
Silver, and
Shovel Projects
Contribution to
Cumulative
Effects
Comments
Magnitude
High
Negligible
Amount of habitat removal due to the Projects is very low
compared to the amount that is currently available in the
CEA study area.
Geographic
Extent
Regional
Local
Duration and
Frequency
Long-term and
Frequent
Long-term and
Infrequent
Reversibility
Long-term
Long-term
Evaluation
Criteria
Context
Moderate
High
The removal of suitable habitat will last the life of the
Projects, which is longer than for timber harvest, as the
area is allowed to regenerate. The Projects will remove
suitable habitat once.
Regional habitat degradation to unsuitable younger
stands can be difficult for the species; however, smaller
openings (i.e., managed rights-of-way) can provide good
forage opportunities.
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Evaluation
Criteria
Significance
Confidence
Cumulative
Effects without
Tretheway, Big
Silver, and
Shovel
Projects
Significant
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Tretheway, Big
Silver, and
Shovel Projects
Contribution to
Cumulative
Effects
Comments
Not significant
The species has already been significantly affected by
past activities. Historic logging may have increased
habitat availability in the CEA study area. The contribution
of the Projects to cumulative effects will not be significant.
Moderate
High
The extent of recruitment of suitable nesting habitat due
to historic logging is uncertain; therefore, the confidence
in the ranking of the cumulative effect of other activities
(without the Projects) is moderate.
15.2.4.2 Timber Resources
As noted in Section 15.2.4.1, the proposed facilities and associated transmission line lie within the Big
Silver and Tretheway LUs in the Chilliwack Forest District, portions of which are considered to be part of
the Timber Harvesting Land Base (THLB). The potential impact of the Project on the THLB has been
assessed by estimating the area and timber type that will be cleared during Project construction. Because
the Shovel Creek and Big Silver Creek Waterpower Projects are located in the same LU and will share
some infrastructure, some of the information presented below pertains to both projects. Note also that a
portion of the transmission line associated with the Big Silver Creek Waterpower Project (i.e., that portion
of the transmission line on the west side of Harrison Lake) is located within the Tretheway LU; because
the THLB is calculated by LU, the assessment of the effects of clearing associated with that portion of the
Big Silver transmission line is included in the assessment of the Tretheway Creek Waterpower Project in
Section 5.2.4.2.
Existing Environmental Conditions
Section 15.2.4.1 provides an overview description of the environmental setting of the Big Silver Creek
Waterpower Project. To facilitate the assessment of potential environmental effects on the THLB, forest
age classes have been mapped (see Maps B01 to B10 in Appendix B of the Hedberg EA in Appendix R
of this Application). These age classes include: young plantations 0 - 15 yrs; free growing plantations 15
- 30 yrs; immature forest 30 - 60 yrs; and forest available for harvest 60+ yrs. Existing forest licence
tenures and cutblocks are also shown, relative to the extent of clearing associated with Project facilities.
The location of OGMAs and forest reserves relative to Project facilities is shown in Appendix A of the
Hedberg EA in Appendix R of this Application.
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Potential Environmental Effects
Project construction will require the clearing of merchantable forest and of areas that are occupied by
immature or un-merchantable stands. Permanent clearing (i.e., areas that will not be revegetated after
Project construction) reduces the extent of the THLB. The total area of THLB within each LU and across
all LUs within a regional Timber Supply Area (TSA) contributes to the Annual Allowable Cut (AAC)
calculation for each TSA. Thus, a significant reduction to the THLB could result in a decrease to the AAC
within the TSA, and thus has the potential to impact LU-level timber supply and individual licensees‟
levels of cut.
In addition, the THLB could be reduced by an accidental wildfire during Project construction or operation.
Estimate of Area Required for Harvest and Clearing
Based on clearing area information obtained from “as-built” surveys of similar run-of-river projects located
around Harrison Lake, the average clearing widths for the various Project components has been
determined. The average area of clearing that is required for the installation of the intake and powerhouse
structure has been determined to be 1.0 ha. This includes clearing for the structures, associated parking
and storage areas, and clearing for the headpond and tailrace. The average width of clearing that is
required for installation of the penstock has been determined to be 50 m. This width is inclusive of
adjacent roads and other areas of permanent clearing required for component construction and operation,
as well as areas required for temporary clearing that will be used for equipment movement and access,
and aggregate borrow, spoil, and laydown areas during construction. The average width of clearing that is
required for installation of the transmission line has been determined to be 30m. This width is inclusive of
adjacent roads and other areas of permanent clearing required for component construction and operation.
Using these average clearing widths, the extent of clearing for Project components, including the
headpond, intake, powerhouse, penstock, transmission line, access roads, and additional construction
use areas (borrow, spoil, and laydown), has been estimated (Table 15-49). Note that these estimates
include both the Shovel Creek and Big Silver Creek Waterpower Projects.
However, the clearing
associated with that portion of the Big Silver transmission line located on the west side of Harrison Lake
(i.e., in the Tretheway LU) is not included here, but is assessed in Section 5.2.4.2 together with the
effects of the Tretheway Creek Waterpower Project.
The final locations of aggregate borrow, spoil, and laydown areas will be determined by site-specific
conditions and will not be defined until construction is underway. Construction logistics, engineered cut
and fill specifications, aggregate grade availability and needs, and the economics of site utilization at the
time of construction will all play a role in the final location of temporary construction areas. However, it is
expected, based on experience with similar projects, that aggregate borrow, spoil, and laydown areas will
be located close to project infrastructure components. Therefore, to accommodate the uncertainty in
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location of aggregate borrow, spoil, and laydown areas, the estimated extent of the area to be cleared for
the Project includes a buffer around project components. Thus, while the spatial distribution of clearing
may shift from the distribution shown in the mapping (Maps B01 to B10 in Appendix B of the Hedberg EA,
included in Appendix R of this Application), the total extent of Project clearing will not exceed the area
estimated below. Further, identified constraints will be avoided during final siting of aggregate borrow,
spoil, and laydown areas.
The extent of clearing for Project components was estimated for each forest cover age class.
Finally, the analysis also identifies the total impact of expected Project clearing, as a percentage of the
31
THLB within the Big Silver LU (as identified in the LU Plan) .
Headpond
Clearing
(ha)
Penstock
Clearing
(ha)
Proposed
Road (ha)
Structure
(ha)
Tx
Line
(ha)
Total
Clearing
Required
(ha)
<15
0
0.8
0
0
0
0.8
15 - 30
0
0
0
0.2
0.6
0.8
30 - 60
1.6
5.4
0.1
1.0
43.1
51.2
> 60
0.9
8.7
0.9
2.2
6.5
19.2
0
0
0
0
0.3
0.3
2.5
14.9
1
3.4
50.5
72.3
Forest Age
(years)
Non-forest
Total
Landscape Unit
Operable Area
Impacted (%)
Estimated Extent of Timber Clearing in the Big Silver LU for the Shovel Creek and
Big Silver Creek Waterpower Projects
Total Operable
Area in
Landscape Unit
(ha)
Table 15-49
18,819
0.4
Mitigation
Mitigation strategies to minimize the extent of productive timber areas affected by Project clearing or
accidental wildfire are presented below.
Revegetation
Areas that are not occupied by Project structures and not required to remain cleared for safety and
access purposes (i.e., transmission line rights-of-way) will be revegetated after construction. A qualified
professional will oversee all revegetation planning and activities.
31
The THLB for each LU includes stands across all age classes that fall within areas that are considered productive in terms of
the ability to grow merchantable timber and are not constrained from harvesting due to regulatory or geographic limitations.
Productive and operable forest areas that are considered constrained through land use planning designations have been
removed from THLB accounting.
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The project CEMP will include BMPs for site evaluation, clearing, soil conservation, and rehabilitation to
ensure opportunities for successful revegetation are maximized. Mitigation measures to conserve and
rehabilitate soil resources during and after construction are described in Section 15.2.1.3. After soil
rehabilitation is complete, where possible (i.e., depending on site conditions), revegetation will include
planting of ecologically suitable tree and understory species, as well as seeding of suitable areas with
herb, shrub, and grass species to promote the development of ecologically appropriate ground cover.
Measures to prevent the introduction of non-native and invasive plant species are identified in
Table 15-43 (in relation to rare plants and rare ecological communities). Revegetated areas are expected
to return to the THLB within the LU.
Some areas affected by construction activities will not be amenable to revegetation. These areas typically
include road cut and fill slopes and/or areas that contain high levels of rock and other materials that are
unsuitable for the growth of vegetation. These areas, in addition to the permanently cleared areas
occupied by Project facilities, will remain as permanent losses to the THLB within the LU. However,
through good planning and development of BMPs (in the CEMP), which provide criteria for the evaluation
of suitable areas prior to clearing and detail procedures to be followed during clearing to maximize
revegetation opportunities, the area of permanent clearing will be minimized.
Revegetation Planning
During construction, a qualified professional will identify areas suitable for revegetation and develop
appropriate site-specific revegetation objectives and prescriptions consistent with the soil rehabilitation
measures described in Section 15.2.1.3.
Revegetation prescriptions will include a description of site conditions and geographic location, and all
revegetation sites will be classified pursuant to the BC Biogeoclimatic Ecosystem Classification (BEC)
system. This system identifies the site by the mix of vegetation, soils, topography, and climate associated
with the site and provides the ecological basis for all revegetation planning throughout the Province.
The site description and identification of the site-level BEC classification will guide planners in identifying
and prescribing appropriate species mixes at appropriate densities.
Revegetation Activities
Tree species selected for revegetation will be appropriate for the site conditions and tree seedlings used
will be consistent with the BC Chief Foresters‟ Standards for Seed Use. These standards define limits to
seed use with respect to distance from area of seed origin and limits to movement above or below the
elevation of origin.
Planting and seeding will be performed using both manual and mechanical means, as appropriate for
revegetation objectives. The revegetation plan will detail the preferred microsite requirements for the
planting of individual tree and regionally approved plant species. A qualified individual will monitor
revegetation activities, to ensure the standards detailed in the revegetation prescription are achieved.
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Revegetation Monitoring
Revegetation monitoring will be completed at the end of the first growing season following revegetation
activities. The Long-Term Monitoring Plan (LTMP) for the Project (see Section 21) will provide the
methodology and reporting requirements for the assessment of revegetation success. The results of the
revegetation monitoring program will inform recommendations for replanting or other vegetation
management activities that may be necessary to ensure revegetation success.
Wildfire Management
The construction and operation of the Project will occur within provincial Crown forest areas. The Wildfire
Act requires all industrial activities adjacent to forested areas to abide by the Act and associated
regulations. In order to reduce the potential for wildfire events, a comprehensive project Fire Abatement
Plan (FAP), consistent with the requirements of the Wildfire Act, will be developed for the construction
and operation phases of the Project. This plan will outline procedures and activity protocols to reduce
both the potential for accidental wildfire to occur and the potential extent and impact of accidental wildfire,
if one were to occur.
The FAP will address wildfire awareness, risk assessment, risk monitoring, activity protocols, fire
equipment, worker training, and wildfire suppression. The development of the FAP will require a complete
Project site assessment prior to construction start-up. This assessment will stratify the Project area into
wildfire risk categories based on the ecological site classification and on the pre-construction site
conditions with respect to fuel loading and topography. Additionally, the assessment will identify the
construction activities expected to occur within each area and classify each expected activity with respect
to wildfire ignition risk. This information will be used to develop Standard Operating Procedures (SOPs)
for each expected activity, based on the risk categories developed for the site and activity classification
combinations.
The FAP will also detail the procedures that will be in place during construction to ensure daily fire risk
levels are monitored and current risk and activity restrictions are effectively communicated.
The FAP will outline requirements for worker training in fire prevention behaviour and wildfire
suppression.
Finally, the FAP will provide a detailed wildfire response plan. This portion of the FAP will identify the
location of fire-fighting resources such as water sources, helicopter landings, access roads, and natural
fire breaks. Additionally, this portion of the FAP will provide detailed requirements for fire-fighting
equipment that will be present and maintained on site during construction and operation.
Application for an Environmental Assessment Certificate
Waterpower Projects
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October 2011
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Residual Environmental Effects Assessment
The Project will be located mainly in forested areas that have previously been disturbed by historic timber
harvesting activities. The previously harvested areas are reforested and have or are developing the
attributes of natural forest stands. Change to forest stand structure is a natural process over time and
forested ecosystems are resilient to site level changes in stand structure.
Only 0.4% of the total THLB within the Big Silver LU will be cleared for the Shovel Creek and Big Silver
Creek Waterpower Projects. The total area planned for clearing by all Three Proposed Projects is less
than 0.1% of the total THLB within the Fraser TSA. As temporarily cleared areas are revegetated and
returned to a productive state (expected within the first ten years of Project operation), the loss to the
THLB will be further reduced. However, areas cleared to accommodate permanent Project facilities
represent a loss to the THLB, and a residual environmental effect from construction is therefore predicted
but is considered to be not significant. Decommissioning of Project facilities may return additional lands to
the THLB.
Implementation of the FPP will render an accidental wildfire unlikely. If a fire were to occur,
implementation of the FPP is expected to eliminate any residual environmental effects due to accidental
wildlife during all phases of the Project.
The analysis of the residual environmental effects of timber harvest and land clearing activities is
summarized in Table 15-50.
Proposed Mitigation
Follow-up
Required?
Potential
Effect
Cumulative
Effect?
Residual Environmental Effects Summary, Rare Plants and Rare Ecological
Communities (Big Silver Creek)
Residual
Effect?
Table 15-50
No
No
See
mitigation
Construction and Decommissioning
Habitat loss and
direct mortality
Clearing will be restricted to carefully flagged areas within
development footprints, except where hazard tree removal is
required.
If facility locations (including access roads, transmission lines, spoil
areas, and laydown sites) change during the final design phase,
new areas will be checked for the presence of rare plants.
Rare plant communities and sensitive ecosystems known or
identified during final design will be avoided and fenced off prior to
construction activities, where located close to any Project footprint.
Disturbance to or in special habitats (e.g., alluvial fans, lake
beaches, non-forested wetlands, rock outcrops, cliffs) will be
avoided to extent feasible.
Natural drainage patterns will be maintained or restored.
Soil rehabilitation and revegetation monitoring will be conducted.
Follow-up
Required?
Proposed Mitigation
Cumulative
Effect?
Potential
Effect
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October 2011
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Residual
Effect?
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Waterpower Projects
No
No
Yes; see
mitigation
Preventing the establishment of invasive species is by far the most
important step in mitigating the risk for introduction. The
government of Canada currently employs inspection techniques at
ports and border crossings to reduce the risk of importing many
invasive insect species, and federal and provincial governments
have strategies to address other points of introduction or spread on
regional levels (Government of Canada 2004)
Rare plant communities and sensitive ecosystems known or
identified during final design will be avoided and fenced off prior to
construction activities, where located close to any Project footprint.
Disturbed sites will be revegetated as soon as possible after
construction with regionally appropriate ground cover, shrubs, or
trees (once erosion concerns have been addressed) and
monitored for revegetation success (see Section 15.2.4.2).
Invasive
species
Prior to any land clearing or soil disturbance activities, a qualified
individual familiar with invasive species identification will conduct a
site survey to locate any occurrences of invasive species in areas
potentially affected by the Project. Known occurrences of invasive
species will be avoided in final facility siting/routing if feasible.
Known occurrences of invasive species in or adjacent to work sites
will be flagged in the field prior to construction.
All construction vehicles and equipment will be thoroughly washed,
paying special attention to undercarriages, wheel wells, tire treads,
and tracks where mud, insect larvae, and seeds may be lodged,
before their arrival to any work site or relocation from any site
where invasive plants are already established. Washing areas will
be located an appropriate distance away from any waterbody and
riparian areas and run-off will be directed away from them.
Domestic animals will be kept out of the work site whenever
possible.
Monitoring for invasive plants at any disturbance/reclaimed site will
continue until revegetated sites are well established.
Environmental Monitor will record presence of any newly
established invasive species determined to be present because of
construction. A professional biologist will assess any such new
populations and develop an invasive plant removal strategy.
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October 2011
Cumulative
Effect?
Follow-up
Required?
- 750 -
Residual
Effect?
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Waterpower Projects
CEMP will include sections on managing construction waste, spill
prevention, and emergency response.
Maintenance and refuelling will be conducted at an approved
distance away from watercourses.
Equipment will be checked to ensure systems are free of leaks and
in good condition.
All machines working near water will have spill kit, trained
operators.
Erosion and sedimentation plan will be in place.
Clearing, grubbing will be minimized, especially in wet weather.
Natural vegetation cover, woody debris, and organic matter will be
retained when possible.
Disturbed areas will be revegetated as soon as possible with
regionally appropriate species.
Soil rehabilitation monitoring will inform recommendations for any
follow-up soil rehabilitation activities that may be necessary to
ensure soil rehabilitation success.
No
No
See
mitigation
Mortality due to
herbicide use
CEMP will include pest management plan with guidance for
herbicide use in areas where rare plants may occur.
No
No
No
Invasive
species
As above for construction and decommissioning.
OPP will specify measures to prevent introduction and/or spread of
invasive species for ongoing maintenance activities, such as
control of vegetation. These measures will be informed by a review
of vegetation management plans developed for transmission line
corridors by BC Hydro, including Integrated Vegetation
Management Plan for Distribution Line Corridors (BC Hydro,
2005), Pest Management Plan for Management of Vegetation at
BC Hydro Facilities (BC Hydro, 2006), and Approved Work
Practices for Managing Riparian Vegetation (BC Hydro et al.,
2003).
Slow-growing later-successional plants may be used to prevent
invasive plant spread and reduce pruning and maintenance
requirement.
No
No
Yes; see
mitigation
Potential
Effect
Introduction of
silt and other
harmful
substances
Proposed Mitigation
Operation
Follow-up and Monitoring
The need for follow-up and monitoring is described in Section 15.2.4.2 and Section 21.
Cumulative Effects Assessment
The other projects and activities that have occurred, are occurring, or will occur within the CEA study area
(see Section 4.6.1) are briefly described below. (Greater detail is provided in Section 15.2.4.1 above,
and in the Forest Resource Values Cumulative Effects Assessment and Section 7.2 of the Keystone EA,
in Appendix P and Appendix K, respectively, of this Application.)
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Past Projects and Activities
The Forest Act Amendment Act was introduced in 1947. Harvesting impacts that preceded that time have
more than likely been mitigated through natural succession and are not considered likely to contribute to
cumulative impacts on forest resource values. Around 1947, the LUs in the study area were characterized
by relatively vast areas of undisturbed old-growth forests and fairly limited resource extraction or industrial
development (McCombs and Chittenden 1988).
Prior to 1960, 6,622 ha of timber had been harvested in the Tretheway, Shovel, and Big Silver CEA study
area combined. This may be an underestimate, as logging regulations and records were not well kept
before the mechanized logging era. Between 1960 and 1990, 21,466 ha of timber were removed in the
Tretheway, Shovel, and Big Silver CEA study area. Between 1990 and 2002, 516 ha of timber were
removed in the Tretheway, Shovel, and Big Silver CEA study area. Cumulatively, 29% of the treed area
in the Tretheway, Shovel, and Big Silver CEA study area had been removed by 2002. Forestry has had
the most impact on the landscape compared to the history of mining, fur trapping, settlement, and fishing
in the area.
Historical forestry (from as early as the 1940s) and associated logging camps are likely a major reason
that wildlife and plants that depend on un-fragmented habitat or large old growth habitat features are rare
on the landscape. The constructions of the railway, Highway 1, and numerous logging roads in the area
have led to additional resource extraction.
Current Projects and Activities
The LUs within the study area are mainly forested areas, with trees up to 250+ years in age, with a
network of forestry roads that were and are used to harvest timber throughout the region. Many creeks
within the study area have water licences for domestic or commercial extraction, as well as small-scale
power generation. The Tipella Creek Waterpower Project is located in the Tretheway LU and the Stokke
Creek Waterpower project is located in the Big Silver LU. The 138kV transmission line associated with the
Stokke Creek project runs to the north along the east side of Harrison Lake from Stokke Creek. There is a
BC Hydro 360 kV transmission line along the west side of Harrison Lake (3L02 circuit) running through
the eastern edge of the Tretheway LU. Within the Big Silver LU, the main transportation artery is the East
Harrison FSR, running along the east side of Harrison Lake and connecting the community of Harrison
Hot Springs to the south, through the Big Silver LU, to the Kookipi Creek FSR which continues north and
east to Boston Bar in the Fraser Canyon. The East Harrison FSR is heavily used by industrial and
recreation traffic from Harrison Hot Springs to Big Silver camp. North of Big Silver camp, the FSR is
mainly used by recreation traffic. Within the Tretheway LU, the main transportation artery is the West
Harrison FSR, running along the west side of Harrison Lake and connecting the communities of Harrison
Mills to the south to the community of Tipella to the north. At Tipella, the West Harrison FSR joins the
Lillooet West FSR and continues north to Pemberton. Currently, north of Bremner Creek, the FSR is in
poor shape and recreation and industrial use is low. Logging camps, airstrips, cabins, recreation sites,
and scattered wilderness campsites and recreational trails also occur in the Big Silver CEA study area.
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The study area has relatively small amounts of old growth forest remaining. To ensure representative old
growth areas remain, Old Growth Management Area targets (OGMAs) have been established for each
LU. Percent area targets have also been established in each LU for Wildlife Tree Retention Areas
(WTRAs) and Wildlife Habitat Areas (WHAs). Regulations for the maintenance of these features have
been developed, which specify limits of disturbance and activity and amendment and replacement
procedures if forestry activities are required within these features. There are a number of licensees that
currently hold tenure and either operate in or have outstanding silviculture obligations within the study
areas. Active forest harvesting and management of outstanding obligations is ongoing.
Future or Proposed Projects and Activities
The scope of other future or proposed projects and activities was described in Section 15.2.4.1.
The AAC for the Fraser TSA is 1.27 million cubic metres a year, with 290,918 ha of land available for
timber harvesting (Pederson 2004). Sixty percent of the Fraser THLB area is less than 60 years of age
(Pederson 2004). It is assumed that a portion of the AAC will be harvested from within the study area
annually. There is one 15.6ha cutblock proposed adjacent to Trio Creek (in the Tretheway LU), but
currently no other cutblocks are proposed. However, as several licensees hold active forest tenure within
the study areas, it is assumed that additional cutblocks are in various stages of development, and that
harvesting activities will continue into the foreseeable future.
Determination of Cumulative Environmental Effects
Other types of projects and activities likely to interact with the residual environmental effects of the Big
Silver Creek Waterpower Project are summarized in Table 15-51.
Timber resources
Loss of productive land from THLB

Recreation

Transportation

Settlements
Residual Environmental Effect of the
Project
Mineral Extraction
Valued
Environmental
Component
Power Generation
and Transmission
Assessment of Potential Interactions between Other Projects and Activities and
Project Residual Environmental Effects within the Big Silver CEA Study Area
Forestry
Table 15-51

The specific projects and activities within these general categories that would most likely interact with the
residual environmental effects of the Big Silver Creek Waterpower Project include forestry (past, present,
and future), the road network (existing), and electrical transmission lines (existing and future).
Application for an Environmental Assessment Certificate
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October 2011
Evaluation of Cumulative Environmental Effects
The primary effect of the Big Silver Creek Waterpower Project on the THLB is a permanent loss of land
area within the LU that is considered to be productive for the growth of merchantable tree species. A total
of 72.3 ha of productive forest land is expected to be cleared in the Big Silver LU for Project components
of both the Shovel Creek and Big Silver Creek Waterpower Projects. This equates to approximately 0.4%
of the total operable, productive land within the LU. (Clearing associated with that portion of the Big Silver
transmission line located on the west side of Harrison Lake (i.e., in the Tretheway LU) is assessed in
Section 5.2.4.2, together with the effects of the Tretheway Creek Waterpower Project.) It is expected that
a portion of this cleared area will be reverted to productive status at the completion of construction
activities. The total area planned for clearing by all Three Proposed Projects is less than 0.1% of the total
THLB within the Fraser TSA. Again, as suitable areas are revegetated, the loss to the THLB will be
further reduced.
Historical forestry activities are the primary contributor to the existing baseline condition of timber
resources. Timber harvesting activities are not considered to contribute to the loss of productive forest
land, as these areas will be reforested and remain productive. However, forestry activities that have
contributed to the loss of productive land include development of road systems, camp locations, log sorts,
and barge landing sites. Forestry will continue to contribute to the loss of productive forest land primarily
through the development and maintenance of forest road systems. Current provincial forestry regulation
specifies the limits of non-productive area (as a percentage of harvested areas) that can be created
during harvesting operations.
Existing transportation and transmission line corridors are classified as unproductive areas within the
study boundaries and therefore are not included in the TLHB. Recent completion of the Tipella Creek
hydroelectric project, within the Tretheway LU, and Stokke Creek hydroelectric project, within the Big
Silver LU, have resulted in the conversion of approximately 40ha from a productive state (including
transmission lines).
Cumulatively, effects on timber resources in the CEA study area can be categorized as nibbling effects.
The effects from the proposed Project combined with the effects from past, current, and ongoing forestry
road development and other land use activities all contribute to incremental losses of land area suitable
for the growth of merchantable tree species within the study area. However, the cumulative effect on
productive forest land is considered to be not significant.
Table 15-52 summarizes the assessment of cumulative environmental effects on timber resources.
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Table 15-52
Evaluation
Criteria
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October 2011
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Timber Resources Cumulative Effects Analysis for Big Silver CEA Study Area
Cumulative
Effects without
Big Silver
Creek Project
Big Silver Creek
Contribution to
Cumulative
Effects
Comments
Amount of productive forest land that will be removed due
to development of the Three Proposed Projects is very
small in relation to the amount of area which is expected
to remain productive within the study area (less than 1%
of the THLB in the Fraser TSA). For the Shovel Creek
and Big Silver Creek Waterpower Projects together, only
0.4% of the THLB within the Big Silver LU will be lost to
Project clearing.
Magnitude
Negligible
Negligible
Geographic
Extent
Sub-regional
Local
The loss of productive forest land will occur only on the
footprint areas of the Project.
Long-term and
Infrequent
Long-term and
Infrequent
Clearing of productive forest land for transportation and
transmission corridors and for Project facilities occurs
once, but these areas are likely to remain in a cleared
state throughout the life of the Project.
Duration and
Frequency
Reversibility
Context
Long-term
High
Long-term
High
Significance
Not significant
Not significant
Confidence
High
High
The loss of productive forest land within the Project
footprint will be a long-term effect lasting for the lifetime of
the Project. It is anticipated the permanent footprint area
can be returned to a productive state upon Project
decommissioning.
Productive forest areas are considered to have a high
resistance to change. Clearing of the Project footprint
areas should have no effect on the function of remaining
productive areas within the study area boundaries.
Other projects and activities have not and are not
expected to have a significant cumulative effect on the
amount of productive forest land within the LU. The Three
Proposed Projects are also expected to result in no
significant adverse cumulative effects on timber
resources.
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15.3
- 755 -
Cloudworks
October 2011
SUMMARY OF ASSESSMENT OF POTENTIAL ENVIRONMENTAL EFFECTS: BIG SILVER CREEK WATERPOWER PROJECT
Valued
Environmental
Components
Potential Effects
Key Mitigation Measures
Significance Analysis of
Residual Environmental
Effects
Construction
Soils
Project facilities will be located in or adjacent to areas of prior disturbance, and will avoid sensitive soils, where feasible.
The extent of clearing, grubbing, and other activities will be restricted to carefully flagged Project footprints.
Pushover logging will not be permitted.
Temporary uses will be located on areas with higher soil rehabilitation potential where feasible.
Soil management practices will meet or exceed applicable guidelines.
Prior to construction, site-specific surveys will be conducted to identify unstable slopes and sensitive soils, and to inform placement of drainage and erosion control structures and soil
handling procedures.
Soil management procedures will be documented in contract specifications (e.g., for road work), and in the CEMP.
Soil in areas not occupied by permanent Project facilities will be rehabilitated as soon as feasible following construction.
Site-specific rehabilitation plans will be developed by a qualified professional.
Erosion and sedimentation plan will be in place.
Natural drainage patterns will be restored.
Soil management in sensitive areas and soil rehabilitation and revegetation will be monitored.
Residual effects, including
cumulative effects, are
expected to be not significant.
Fugitive dust
Limit vehicle speeds.
Water areas in dry conditions.
Replant areas and minimize exposed soils.
Moisten fine materials or use covers on dump trucks.
Residual effects, including
cumulative effects, are
expected to be not significant.
GHG and CAC
emissions
Minimize idling and turn off machinery when not in use.
Operate equipment at optimum loads
Ensure proper maintenance of equipment
Residual effects, including
cumulative effects, are
expected to be not significant.
None
The Project may reduce or
avoid GHG (and CAC)
emissions associated with the
generation of the equivalent
amount of electricity by fossil
fuel combustion elsewhere.
This is considered a positive
effect.
Loss of soil productivity
and hydrologic function
Construction
Air Quality
GHG offset/reduction
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Valued
Environmental
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Potential Effects
Key Mitigation Measures
Cloudworks
October 2011
Significance Analysis of
Residual Environmental
Effects
Construction and Decommissioning of Temporary Facilities
Changes to TSS,
turbidity, DO
Construction work in the dry.
Implementation of CEMP incorporating relevant BMPs, addressing isolation of work areas, erosion and sediment control, soil management, bank stabilization, revegetation, waste
management (including organic debris), and fire prevention and response.
Steep and turbulent nature of the diversion reach and cold stream temperatures will moderate effects.
Managed discharge of stored water.
Channel design to minimize water temperature increases.
Residual effects, including
cumulative effects, are
expected to be not significant.
Changes to pH and
nitrogen
Implementation of CEMP incorporating relevant BMPs, addressing blast residue and blast rock use and ARD/ML (see below).
Residual effects, including
cumulative effects, are
expected to be not significant.
Accidental spills of
contaminants
Construction work in the dry.
Implementation of CEMP incorporating relevant BMPs addressing hazardous and toxic materials management, spill prevention and response, waste management, and education and
training.
Use of environmentally appropriate lubricants and coolants.
Residual effects, including
cumulative effects, are
expected to be not significant.
Changes due to
ARD/ML, blasting
Sampling of rocks for acid-generating potential.
Containing, neutralizing any potentially acid-generating waste rock.
Water sampling to monitor ARD/ML near spoil sites.
Residual effects, including
cumulative effects, are
expected to be not significant.
Changes to all water
quality parameters
Implementation of CEMP incorporating relevant BMPs.
Stabilizing exposed areas to be flooded and filling in the headpond slowly.
Penstock flush water stored before discharge to stream.
Residual effects, including
cumulative effects, are
expected to be not significant.
Accidental spills of
contaminants
As above for construction and decommissioning of temporary facilities.
Residual effects, including
cumulative effects, are
expected to be not significant.
Changes to TSS and
turbidity
Implementation of OPP incorporating relevant BMPs.
Vegetation between the road and the stream left as intact as possible.
Headpond flushing during natural high flow events.
Residual effects, including
cumulative effects, are
expected to be not significant.
Changes to DO and
TGP
Same as for TSS and turbidity.
Headpond infilling over time.
Design features to prevent air entrainment.
Mixing and turbulence in the tailrace and downstream reach.
Residual effects, including
cumulative effects, are
expected to be not significant.
Accidental spills of
contaminants
As above for construction and decommissioning of temporary facilities.
Residual effects, including
cumulative effects, are
expected to be not significant.
Changes to TSS,
turbidity, DO
Same as for construction (or more stringent standards in effect at the time, if any).
Residual effects, including
cumulative effects, are
expected to be not significant.
Changes to pH,
nitrogen, contaminants
Same as for construction (or more stringent standards in effect at the time, if any).
Residual effects, including
cumulative effects, are
expected to be not significant.
Commissioning
Water Quality
Operation
Decommissioning
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Valued
Environmental
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Potential Effects
Key Mitigation Measures
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October 2011
Significance Analysis of
Residual Environmental
Effects
Construction and Decommissioning of Temporary Facilities
Fish Rearing and
Overwintering
Habitat
Substrate movement
Duration of construction minimized.
No residual effects or
cumulative effects are
expected.
Burying underwater
transmission line cable
on east and west
shores of Harrison Lake
Shoreline rebuilt with regionally approved materials and following the natural grade.
No residual effects or
cumulative effects are
expected.
Water quality, physical
disturbance due to
blasting
Construction work in the dry.
Implementation of CEMP incorporating relevant BMPs addressing blast residue and blast rock use.
Residual effects, including
cumulative effects, are
expected to be not significant.
Increased water
temperature
Minimize extent of riparian disturbance.
Implementation of CEMP incorporating relevant BMPs addressing revegetation.
Residual effects, including
cumulative effects, are
expected to be not significant.
Short-term habitat loss
Instream work during fisheries windows.
Fish salvage.
Buried penstock crossings.
Stream channel rebuilt using natural materials, grade.
Fording avoided or in compliance with DFO guidelines.
Implementation of CEMP incorporating relevant BMPs addressing waste management, hazardous materials management, spill prevention and response, revegetation.
Residual effects, including
cumulative effects, are
expected to be not significant.
Long-term habitat loss
Minimized extent of disturbance.
Unavoidable habitat loss offset by suitable compensation habitat at appropriate ratios.
Monitoring of compensation habitat function.
Compensation habitat maintenance at full function for life of project.
Residual effects, including
cumulative effects, are
expected to be not significant.
Compliance with standard ramping rates unless less stringent rates demonstrated to be acceptable.
Ramping rate tests to determine ramping rates protective of fish.
Maintenance of IFR.
Fish stranding contingency plan.
Fire prevention and response measures.
Residual effects, including
cumulative effects, are
expected to be not significant.
Commissioning
Changes in flow
Operation
Implementation of OPP, including maintenance of IFR, emergency response procedures, and fire prevention and response.
Unavoidable habitat loss offset by compensation habitat per construction.
Residual effects, including
cumulative effects, are
expected to be not significant.
Changes in flow due to
ramping
Implementation of OPP, including adherence to ramping rates protective of fish, fish stranding contingency plan, and emergency response procedures.
Continuous flow monitoring.
Residual effects, including
cumulative effects, are
expected to be not significant.
Extreme changes in
water temperature
Natural conditions will moderate temperature.
Water temperature monitoring and adaptive management as required.
Residual effects, including
cumulative effects, are
expected to be not significant.
Bedload trapping and
backwatering upstream
of the diversion weir
Mitigated over time through headpond infilling.
Implementation of OPP, including annual sediment sluicing from headpond.
Residual effects, including
cumulative effects, are
expected to be not significant.
Water quality, physical
disturbance due to
blasting
Same as for construction (or more stringent standards in effect at the time, if any).
Residual effects, including
cumulative effects, are
expected to be not significant.
Increased water
temperature, habitat
loss
Same as for construction (or more stringent standards in effect at the time, if any).
Residual effects, including
cumulative effects, are
expected to be not significant.
Loss of habitat due to
flow diversion
Decommissioning
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Valued
Environmental
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Potential Effects
Key Mitigation Measures
Cloudworks
October 2011
Significance Analysis of
Residual Environmental
Effects
Construction and Decommissioning of Temporary Facilities
Substrate movement
Duration of construction minimized.
No residual effects or
cumulative effects are
expected.
Burying underwater
transmission line cable
on east and west
shores of Harrison Lake
Shoreline rebuilt with regionally approved materials and following the natural grade.
No residual effects or
cumulative effects are
expected.
Water quality, physical
disturbance due to
blasting
As above for fish rearing and overwintering habitat
Residual effects, including
cumulative effects, are
expected to be not significant.
As above for fish rearing and overwintering habitat
Residual effects, including
cumulative effects, are
expected to be not significant.
Loss of habitat due to
flow diversion
As above for fish rearing and overwintering habitat
Residual effects, including
cumulative effects, are
expected to be not significant.
Changes in flow due to
ramping
As above for fish rearing and overwintering habitat
Residual effects, including
cumulative effects, are
expected to be not significant.
Extreme changes in
water temperature
As above for fish rearing and overwintering habitat
Residual effects, including
cumulative effects, are
expected to be not significant.
Commissioning
Changes in flow
Fish Spawning
and Incubation
Habitat
Operation
Bedload trapping by the
diversion weir
Unavoidable habitat loss offset by compensation habitat.
Implementation of OPP, including annual sediment sluicing from headpond.
Residual effects, including
cumulative effects, are
expected to be not significant.
Decommissioning
Same as during
construction
Same as for construction (or more stringent standards in effect at the time, if any).
Residual effects, including
cumulative effects, are
expected to be not significant.
Application for an Environmental Assessment Certificate
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Valued
Environmental
Components
- 759 -
Potential Effects
Key Mitigation Measures
Cloudworks
October 2011
Significance Analysis of
Residual Environmental
Effects
Construction and Decommissioning of Temporary Facilities
Water quality, physical
disturbance due to
blasting and
As above for fish rearing and overwintering habitat
No residual effects or
cumulative effects are
expected.
Compliance with standard ramping rates unless less stringent rates demonstrated to be acceptable.
Ramping rate tests to determine ramping rates protective of fish.
Maintenance of IFR.
Fish stranding contingency plan.
Residual effects, including
cumulative effects, are
expected to be not significant.
Commissioning
Changes in flow
Fish Migratory
Habitat
Operation
Attraction to tailrace
flows
Reduced flows in
diversion reach
impeding up/
downstream migration
No anadromous fish are able to access the diversion reach and there is low utilization of the lower diversion reach by Dolly Varden and rainbow trout.
Residual effects, including
cumulative effects, are
expected to be not significant.
Implementation of OPP, including maintenance of IFR, ramping rate protocols, and emergency response procedures.
Residual effects, including
cumulative effects, are
expected to be not significant.
Decommissioning
Same as during
construction
Same as for construction (or more stringent standards in effect at the time, if any).
No residual effects or
cumulative effects are
expected.
Construction and Decommissioning of Temporary Facilities
Riparian Habitat
Short-term habitat loss
Avoidance of (high/climax value) riparian habitat where possible.
Minimized extent of riparian disturbance.
Site-specific vegetation characteristics documented prior to disturbance to inform restoration prescriptions.
Site-specific riparian restoration treatments/prescriptions for on- and off-site areas.
Implementation of CEMP incorporating relevant BMPs addressing erosion and sediment control, soil management, invasive plant management, revegetation, and fire prevention and
response.
Minimized use of machinery and equipment in RMZ.
Monitoring of revegetation for 5 years post-construction, and to ensure compensation habitat is effective.
Residual effects, including
cumulative effects, are
expected to be not significant.
Long-term loss of
habitat function
As above for short term habitat loss.
Residual effects, including
cumulative effects, are
expected to be not significant.
Slow filling of headpond.
Location of penstock flush water pond outside of RMZ if possible.
No residual effects or
cumulative effects are
expected.
Use of the BC Hydro Integrated Vegetation Management Plan for Transmission Rights-of-way (BC Hydro, 2010) for vegetation management.
Habitat loss addressed in construction phase above.
Implementation of OPP, including emergency response procedures and fire prevention and response.
Residual effects, including
cumulative effects, are
expected to be not significant.
Same as for construction (or more stringent standards in effect at the time, if any).
Some Project infrastructure may remain in place for bank stabilization, if appropriate.
Floristic succession will return all areas to climax riparian function.
Residual effects, including
cumulative effects, are
expected to be not significant.
Commissioning
Bank stability,
disturbance to riparian
habitat
Operation
Maintenance of early
seral stage on ROWs
Decommissioning
Loss of habitat function,
bank instability
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Temporary decline in
invertebrate production
and loss of habitat
Macroinvertebrate drift will continue through diversion channel.
Minimized duration of construction.
Implementation of CEMP incorporating relevant BMPs addressing erosion and sediment control, bank stabilization, and revegetation.
Natural recolonization after disturbance.
Compensation for unavoidable habitat loss.
Residual effects, including
cumulative effects, are
expected to be not significant.
Compliance with standard ramping rates unless less stringent rates demonstrated to be acceptable.
Ramping rate tests to determine ramping rates protective of fish.
Maintenance of IFR.
Residual effects, including
cumulative effects, are
expected to be not significant.
Commissioning
Dewatering, stranding
of invertebrates
Operation
Implementation of OPP, including maintenance of IFR, ramping protocols, and emergency response procedures.
Macroinvertebrate
Habitat
Reduced habitat, flood
flows
Channel-forming flows will still occur.
Unavoidable habitat loss offset by compensation habitat per construction.
Residual effects, including
cumulative effects, are
expected to be not significant.
Water temperature
Temperature monitored continuously during the first five years of operation.
Residual effects, including
cumulative effects, are
expected to be not significant.
Habitat alteration in
headpond
Headpond infilling over time, development of variety of substrates.
Residual effects, including
cumulative effects, are
expected to be not significant.
Bedload trapping in the
headpond.
Annual sluicing of sediment from headpond.
Residual effects, including
cumulative effects, are
expected to be not significant.
Same as for construction (or more stringent standards in effect at the time, if any).
Residual effects, including
cumulative effects, are
expected to be not significant.
Decommissioning
Same as during
construction
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Habitat loss and
fragmentation
Clearing will be restricted to carefully flagged areas within development footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with ground cover, shrubs, or trees that are regionally appropriate (once erosion concerns have been addressed).
„Soft edges‟ will be created along right-of-way and access roads by maintaining shrub species along the forest edge. Relevant portions of Section 3 (Site Development and Management)
of the Develop with Care (BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along forested and riparian edges.
Connectivity at stream crossings will be encouraged by limiting riparian clearing to the access road footprint or penstock where they cross the stream.
Creek crossings (for creeks with year-round flow) will be surveyed prior to construction to determine tailed frog presence. Water diverted around construction site will be returned to the
same stream immediately downstream of the work site when tailed frog tadpoles are observed.
Construction and maintenance activities in and around watercourses will conform to Standards and Best Practices for Instream Works (BC MWLAP 2004), Best Management Practices
for Amphibians and Reptiles (Ovaska et al. 2004), and other approved work practices, where feasible.
Residual effects, including
cumulative effects, are
expected to be not significant.
Introduction of silt and
other harmful
substances
BMPs will be followed for in-stream works.
CEMP will include sections on managing construction waste, spill prevention, and emergency response.
Maintenance and refuelling will be conducted at an approved distance away from watercourses.
Equipment will be checked to ensure systems are free of leaks and in good condition.
All machines working near water will have spill kit, trained operators.
Erosion and sedimentation plan will be in place.
Clearing, grubbing will be minimized, especially in wet weather. Natural vegetation cover, woody debris, and organic matter will be retained when possible.
Disturbed areas will be revegetated as soon as possible with regionally appropriate species.
Residual effects, including
cumulative effects, are
expected to be not significant.
Direct Mortality
As above for habitat loss.
Permits will be in place to salvage tailed frog tadpoles (or adults) during diversion of any stream for intake or penstock construction.
Residual effects, including
cumulative effects, are
expected to be not significant.
Habitat alteration,
mortality due to
herbicide use
CEMP will include pest management plan with guidance for herbicide use.
Broadcast spraying of chemical defoliants will be avoided around potential breeding sites.
No residual effects or
cumulative effects are
expected.
Flow regulation in
diversion reach
Flow within diversion reach will be maintained as defined by operating parameters set by provincial government. Strategies will be in place to maintain fish habitat as described in
Aquatic Environment section.
No residual effects or
cumulative effects are
expected.
Potential Effects
Construction and Decommissioning
Pacific Tailed
Frog
Operation
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Habitat loss and
fragmentation
Clearing will be restricted to carefully flagged areas within development footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate ground cover, shrubs, or trees (once erosion concerns have been addressed).
„Soft edges‟ will be created along right-of-way and access roads by maintaining shrub species along the forest edge. Relevant portions of Section 3 (Site Development and Management)
of the Develop with Care (BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along forested and riparian edges.
Connectivity at stream crossings will be encouraged by limiting riparian clearing to the access road footprint.
Larger culverts or bridge crossings will be used.
Construction and maintenance activities in and around watercourses will conform to Standards and Best Practices for Instream Works (BC MWLAP 2004), Best Management Practices
for Amphibians and Reptiles (Ovaska et al. 2004), and other approved work practices, where feasible.
No residual effects or
cumulative effects are
expected.
Introduction of silt and
other harmful
substances
As above for Pacific Tailed Frog.
No residual effects or
cumulative effects are
expected.
Increased road
mortality and direct
mortality
Construction activities will be avoided in/around wetlands (where amphibian breeding is noted) to extent feasible.
If unavoidable, construction in these areas will be scheduled after breeding is complete and toadlets/juveniles have dispersed where feasible and appropriate.
Natural drainage will be maintained to protect wetland hydrology.
If construction cannot be rescheduled, Environmental Monitor will install fencing to direct amphibian migrations away from roads, or culverts to be installed to direct amphibians safely
across the road. These measures will be monitored during peak amphibian activity to ensure they are effective.
Congregrations and mortality of toadlets/amphibians will be reported to Environmental Monitor, who will identify problem areas and implement additional measures (such as fencing), as
required.
No residual effects or
cumulative effects are
expected.
Habitat alteration,
mortality due to
herbicide use
Maintenance workers will be informed of potential amphibian use and/or congregations if maintenance activities occur during the times of the year when congregations are anticipated.
As above for Pacific Tailed Frog.
No residual effects or
cumulative effects are
expected.
Increased road
mortality
Maintenance work in or adjacent to known locations of amphibian congregations identified during construction will be scheduled for times when congregations are absent, to the extent
feasible.
Congregrations and mortality of toadlets/amphibians will be reported to Environmental Monitor, who will identify problem areas and implement additional measures (such as fencing), as
required.
No residual effects or
cumulative effects are
expected.
Western Toad
Operation
Construction and Decommissioning
Red-legged Frog
Habitat loss and
fragmentation
As above for Western Toad.
No residual effects or
cumulative effects are
expected.
Introduction of silt and
other harmful
substances
As above for Pacific Tailed Frog.
No residual effects or
cumulative effects are
expected.
Increased road
mortality and direct
mortality
As above for Western Toad.
No residual effects or
cumulative effects are
expected.
Habitat alteration,
mortality due to
herbicide use
As above for Western Toad.
No residual effects or
cumulative effects are
expected.
Increased road
mortality
As above for Western Toad.
No residual effects or
cumulative effects are
expected.
Operation
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Rubber Boa
Habitat loss and
fragmentation,
associated mortality
Clearing will be restricted to carefully flagged areas within development footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate ground cover, shrubs, or trees (once erosion concerns have been addressed).
„Soft edges‟ will be created along right-of-way and access roads by maintaining shrub species along the forest edge. Relevant portions of Section 3 (Site Development and Management)
of the Develop with Care (BC MOE 2006a) document will be applied, when appropriate.
Some large CWD will be left in cleared areas and placed along forested and riparian edges.
No residual effects or
cumulative effects are
expected.
Construction and Decommissioning
Northern
Goshawk
Habitat loss and
fragmentation
Inactive or active nests found in close proximity to construction areas will be reported to the Environmental Monitor.
Appropriate setback buffers will be established around active nests (if any are identified) (per BMPs in Demarchi and Bentley 2005, BC MOE 2006a) and will be monitored during
construction, if work must commence during the breeding season and the active nest is adjacent to a work site.
As above for Rubber Boa.
Rather than completely removing some large trees near the edge of a footprint, the possibility of creating snags by “stubbing” will be considered, providing it is safe to do so.
Mature and old-growth forest will be avoided and existing disturbance corridors followed, where feasible.
Residual effects, including
cumulative effects, are
expected to be not significant.
Construction and Decommissioning
Nest loss and
disturbance due to loud
construction noise
Great Blue Heron
Great Blue Heron nests are protected by law; lead regulatory agency will be consulted if nests are identified in or near (within 500 m) final Project footprints.
Areas within 500 m of any Project footprints will be surveyed prior to construction to identify any large stick nests.
Inactive or active nests found in close proximity to construction areas will be reported to the Environmental Monitor.
Appropriate setback buffers will be established around active nests (if any are identified) (per BMPs in Demarchi and Bentley 2005, BC MOE 2006a) and will be monitored during
construction, if work must commence during the breeding season and the active nest is adjacent to a work site.
If a vacant nest is located in a Project footprint and cannot be avoided, the lead regulatory agency will be consulted to develop a plan to relocate the nest.
No residual effects or
cumulative effects are
expected.
The configuration of the conductors on the transmission line poles will reduce and likely eliminate potential for avian electrocution.
If avian mortality due to collision or electrocution is suspected, the transmission line will be monitored and preventative measures put into place, under the guidance of a qualified
professional biologist.
No residual effects or
cumulative effects are
expected.
As above for Rubber Boa.
Mature and old-growth forest will be avoided and existing disturbance corridors followed, where feasible.
No residual effects or
cumulative effects are
expected.
As above for Great Blue Heron.
No residual effects or
cumulative effects are
expected.
Operation
Avian mortality from
transmission line
Construction
Habitat loss
Olive-sided
Flycatcher
Operation
Avian mortality from
transmission line
Construction and Decommissioning
Nest loss and
disturbance due to loud
construction noise
Bald Eagle nests are protected by law; lead regulatory agency will be consulted if nests are identified in or near (within 500 m) final Project footprints.
As above for Great Blue Heron.
No residual effects or
cumulative effects are
expected.
Bald Eagle
Operation
Avian mortality from
transmission line
As above for Great Blue Heron
No residual effects or
cumulative effects are
expected.
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American Dipper
Habitat alteration,
displacement due to
disturbance
Instream works will be scheduled over short periods during dry season.
As above for Rubber Boa.
No residual effects or
cumulative effects are
expected.
Construction and Decommissioning
Harlequin Duck
Habitat loss and
fragmentation
As above for Rubber Boa.
No residual effects or
cumulative effects are
expected.
Disturbance due to loud
construction noise
Before construction within 50 m of suitable Harlequin Duck nesting habitat during the breeding season (April 1 to August 31), a Harlequin Duck nest survey will be conducted by a
qualified professional in accordance with current standards and guidelines. If a suspected nest site is located, work will be delayed in the area until ducklings have left the area.
No residual effects or
cumulative effects are
expected.
As above for Rubber Boa.
Rather than completely removing some large trees near the edge of a footprint, the possibility of creating snags by “stubbing” will be considered, providing it is safe to do so.
Mature and old-growth forest will be avoided and existing disturbance corridors followed, where feasible.
If a nest tree is removed, placement of nest boxes will be considered.
No residual effects or
cumulative effects are
expected.
Clearing will be restricted to carefully flagged areas within development footprints, except where hazard tree removal is required.
Disturbed sites will be replanted quickly with regionally appropriate ground cover, shrubs, or trees (once erosion concerns have been addressed).
„Soft edges‟ will be created along right-of-way and access roads by maintaining shrub species along the forest edge. Relevant portions of Section 3 (Site Development and Management)
of the Develop with Care (BC MOE 2006a) document will be applied, when appropriate.
Residual effects, including
cumulative effects, are
expected to be not significant.
As above for Great Blue Heron.
No residual effects or
cumulative effects are
expected.
Vegetation clearing will take place outside of the breeding bird season (March 15 to August 15) where possible to prevent disturbance of bird nests
If clearing takes place during the breeding season, qualified professionals will complete nest surveys prior to construction to determine if nesting is occurring in the area. If nests are
located, appropriate setback buffers for disturbance will be applied.
No residual effects or
cumulative effects are
expected.
Avian mortality from
transmission line
As above for Great Blue Heron.
No residual effects or
cumulative effects are
expected.
Nest abandonment and
direct mortality due to
clearing
As above for construction.
No residual effects or
cumulative effects are
expected.
As above for Rubber Boa.
Rather than completely removing some large trees near the edge of a footprint, the possibility of creating snags by “stubbing” will be considered, providing it is safe to do so.
Mature and old-growth forest will be avoided and existing disturbance corridors followed, where feasible.
Residual effects, including
cumulative effects, are
expected to be not significant.
Construction
Western Screechowl
Habitat loss and
fragmentation
Construction
Habitat loss and
fragmentation
Band-tailed
Pigeon
Operation
Avian mortality from
transmission line
Construction
Nest abandonment and
direct mortality due to
clearing
Operation
Migratory Birds
Construction
Spotted Owl
Habitat loss and
fragmentation
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Increased hunting
mortality
Crews will be prohibited from hunting in the area.
Temporary roads and staging/spoil areas will be deactivated and planted with appropriate vegetation when no longer needed.
Road deactivation will include measures designed to prevent ATV access.
No residual effects or
cumulative effects are
expected.
Increased road
mortality
Safe speed limits along access roads will be imposed.
Contractors/crews will be encouraged to use as few vehicles as possible to access work site.
Wildlife observations will be recorded; Environmental Monitor will inform drivers of road sections frequented by wildlife.
Temporary roads will be deactivated and re-planted with appropriate vegetation when no longer needed.
Revegetation will use unpalatable regionally approved vegetation when re-planting cleared roadsides where feasible, to discourage foraging.
No residual effects or
cumulative effects are
expected.
Columbian
Black-tailed Deer
Construction, Operation, and Decommissioning
Grizzly and Black
Bears
Problem animal
mortality
Crews will participate in an appropriate wildlife awareness training program, and be instructed to refrain from feeding wildlife.
Food scraps and garbage from construction sites will be removed or stored in bear-proof containers for proper disposal.
Work crews will be prohibited from hunting and cleaning game in the Project area.
Nuisance bears will be reported to a Conservation Officer, who would assist in determining appropriate measures.
Human-Bear Conflict Management measures will be developed and included in the CEMP to provide clear procedures for handling bears that wander onto work sites.
All road kill will be promptly moved from roadways to prevent scavenging wildlife (including bears) from being attracted to the roads.
Revegetation will use unpalatable regionally approved vegetation when re-planting cleared roadsides where feasible, to discourage foraging.
Wildlife observations will be recorded; Environmental Monitor will inform drivers of road sections frequented by wildlife.
No residual effects or
cumulative effects are
expected.
Construction and Decommissioning
Habitat loss and
fragmentation
Pacific Sideband
As above for Rubber Boa.
No residual effects or
cumulative effects are
expected.
CEMP will include pest management plan with guidance for herbicide use in areas where species-at-risk may occur.
No residual effects or
cumulative effects are
expected.
Operation
Habitat alteration,
mortality due to
herbicide use
Construction and Decommissioning
Black Petaltail
Habitat loss and
fragmentation
Clearing will be restricted to carefully flagged areas within development footprints, except where hazard tree removal is required.
Sensitive ecosystems (wetlands) will be avoided during final project design to the extent feasible.
Areas to be avoided will be identified and fenced off prior to construction activities, if located adjacent to the Project footprint.
No residual effects or
cumulative effects are
expected.
Introduction of silt and
other harmful
substances
BMPs will be followed for in-stream works.
CEMP will include sections on managing construction waste, spill prevention, and emergency response.
Equipment will be checked to ensure systems are free of leaks and in good condition.
All machines working near water will have spill kit, trained operators.
Erosion and sedimentation plan will be in place.
No residual effects or
cumulative effects are
expected.
As above for Pacific Sideband.
No residual effects or
cumulative effects are
expected.
Operation
Habitat alteration,
mortality due to
herbicide use
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Habitat loss and direct
mortality
Clearing will be restricted to carefully flagged areas within development footprints, except where hazard tree removal is required.
If facility locations (including access roads, transmission lines, spoil areas, and laydown sites) change during the final design phase, new areas will be checked for the presence of rare
plants.
Rare plant communities and sensitive ecosystems known or identified during final design will be avoided and fenced off prior to construction activities, where located close to any Project
footprint.
Disturbance to or in special habitats (e.g., alluvial fans, lake beaches, non-forested wetlands, rock outcrops, cliffs) will be avoided to extent feasible.
Natural drainage patterns will be maintained or restored.
Soil rehabilitation and revegetation monitoring will be conducted.
No residual effects or
cumulative effects are
expected.
Invasive species
Preventing the establishment of invasive species is by far the most important step in mitigating the risk for introduction. The government of Canada currently employs inspection
techniques at ports and border crossings to reduce the risk of importing many invasive insect species, and federal and provincial governments have strategies to address other points of
introduction or spread on regional levels (Government of Canada 2004)
Rare plant communities and sensitive ecosystems known or identified during final design will be avoided and fenced off prior to construction activities, where located close to any Project
footprint.
Disturbed sites will be revegetated as soon as possible after construction with regionally appropriate ground cover, shrubs, or trees (once erosion concerns have been addressed) and
monitored for revegetation success.
Prior to any land clearing or soil disturbance activities, a qualified individual familiar with invasive species identification will conduct a site survey to locate any occurrences of invasive
species in areas potentially affected by the Project. Known occurrences of invasive species will be avoided in final facility siting/routing if feasible. Known occurrences of invasive species
in or adjacent to work sites will be flagged in the field prior to construction.
All construction vehicles and equipment will be thoroughly washed, paying special attention to undercarriages, wheel wells, tire treads, and tracks where mud, insect larvae, and seeds
may be lodged, before their arrival to any work site or relocation from any site where invasive plants are already established. Washing areas will be located an appropriate distance away
from any waterbody and riparian areas and run-off will be directed away from them.
Domestic animals will be kept out of the work site whenever possible.
Monitoring for invasive plants at any disturbance/reclaimed site will continue until revegetated sites are well established. Environmental Monitor will record presence of any newly
established invasive species determined to be present because of construction. A professional biologist will assess any such new populations and develop an invasive plant removal
strategy.
No residual effects or
cumulative effects are
expected.
Introduction of silt and
other harmful
substances
CEMP will include sections on managing construction waste, spill prevention, and emergency response.
Maintenance and refuelling will be conducted at an approved distance away from watercourses.
Equipment will be checked to ensure systems are free of leaks and in good condition.
All machines working near water will have spill kit, trained operators.
Erosion and sedimentation plan will be in place.
Clearing, grubbing will be minimized, especially in wet weather. Natural vegetation cover, woody debris, and organic matter will be retained when possible.
Disturbed areas will be revegetated as soon as possible with regionally appropriate species.
Soil rehabilitation monitoring will inform recommendations for any follow-up soil rehabilitation activities that may be necessary to ensure soil rehabilitation success.
No residual effects or
cumulative effects are
expected.
Mortality due to
herbicide use
CEMP will include pest management plan with guidance for herbicide use in areas where rare plants may occur.
No residual effects or
cumulative effects are
expected.
Invasive species
As above for construction and decommissioning.
OPP will specify measures to prevent introduction and/or spread of invasive species for ongoing maintenance activities, such as control of vegetation. These measures will be informed
by a review of vegetation management plans developed for transmission line corridors by BC Hydro, including Integrated Vegetation Management Plan for Distribution Line Corridors (BC
Hydro, 2005), Pest Management Plan for Management of Vegetation at BC Hydro Facilities (BC Hydro, 2006), and Approved Work Practices for Managing Riparian Vegetation (BC
Hydro et al., 2003).
Slow-growing later-successional plants may be used to prevent invasive plant spread and reduce pruning and maintenance requirement.
No residual effects or
cumulative effects are
expected.
Rare Plants and
Rare Ecological
Communities
Operation
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Clearing will be restricted to carefully flagged areas within development footprints, except where hazard tree removal is required.
Areas not occupied by Project structures and not required to remain cleared for safety and access purposes will be revegetated after construction. A qualified professional will oversee all
revegetation planning and activities.
The CEMP will include BMPs for site evaluation, clearing, soil conservation, and rehabilitation to ensure opportunities for successful revegetation are maximized.
After soil rehabilitation, depending on site conditions, revegetation will include planting ecologically suitable tree and understory species, as well as seeding of suitable areas with herb,
shrub, and grass species to promote development of ecologically appropriate ground cover.
Soil rehabilitation and revegetation monitoring will be conducted.
Residual effects, including
cumulative effects, are
expected to be not significant.
Potential Effects
Construction
Loss of timber
resources due to
clearing
Timber Resources
Construction, Operation, and Decommissioning
Loss of timber
resources due to fire
Fire Abatement Plan will be prepared for all Project phases.
FAP will address wildfire awareness, risk assessment, risk monitoring, activity protocols, fire-fighting resources and equipment, worker training, and wildfire response and suppression.
No residual effects or
cumulative effects are
expected.