Draft Environmental Assessment Cabeza Prieta National Wildlife

Transcription

Draft
Environmental Assessment
Cabeza Prieta National Wildlife Refuge Sonoran Pronghorn
Supplemental Water and Forage Project
Lead Agency: U.S. Department of the Interior
Fish and Wildlife Service
Cabeza Prieta National Wildlife Refuge
Cooperating Agency: Arizona Game and Fish Department
Prepared by
Sidney C. Slone
Refuge Manager
Ajo, Arizona
May 2011
TABLE OF CONTENTS
LIST OF ACRONYMS ............................................................................................................................... iv
1.0 PROPOSED ACTION ............................................................................................................................ 1
1.1 Introduction ......................................................................................................................................... 1
1.2 Proposed Action .................................................................................................................................. 1
1.3 Location .............................................................................................................................................. 3
1.3.1 Proposed New Catchments and Modification of Existing Catchments ....................................... 3
1.3.2 Proposed Placement of Temporary Waters .................................................................................. 3
1.3.3 Proposed Supplemental Feeding.................................................................................................. 5
1.4 Best Management Practices/Conservation Measures.......................................................................... 6
1.4.1 Water Developments.................................................................................................................... 6
1.4.2 Supplemental Forage ................................................................................................................... 7
1.4.3 Additional Measures .................................................................................................................... 7
1.6 Purpose of Action.............................................................................................................................. 12
1.7 Need for Action ................................................................................................................................. 12
1.8 Decision to be Made ......................................................................................................................... 13
1.9 Regulatory Compliance..................................................................................................................... 13
1.10 Scoping/Public Involvement and Issues Identified ......................................................................... 14
2.0 ALTERNATIVES................................................................................................................................. 14
2.1 No Action Alternative....................................................................................................................... 14
2.1.1 Water Catchments ...................................................................................................................... 16
2.1.2 Temporary Water and Supplemental Feeding ........................................................................... 16
2.2 Alternatives Considered But Dismissed From Detailed Analysis .................................................... 17
3.0 AFFECTED ENVIRONMENT ............................................................................................................ 18
3.1 Physical Environment ....................................................................................................................... 18
3.1.1 Air Quality ................................................................................................................................. 19
3.1.2 Soils ........................................................................................................................................... 19
3.1.3 Water Resources and Quality..................................................................................................... 20
3.2 Biological Environment .................................................................................................................... 20
3.2.1 Vegetative Communities............................................................................................................ 20
3.2.2 Wildlife ...................................................................................................................................... 21
3.2.3 Threatened and Endangered Species and Other Special Status Species .................................... 21
i
Sonoran Pronghorn Supplemental Water and Forage Project Draft EA
May 2011
3.3 Human Environment ......................................................................................................................... 26
3.3.1 Cultural Resources ..................................................................................................................... 26
3.3.2 Recreation .................................................................................................................................. 27
3.4 Natural Environment ......................................................................................................................... 27
3.4.1 Visual Resources........................................................................................................................ 27
3.4.2 Wilderness ................................................................................................................................. 28
4.0 ENVIRONMENTAL CONSEQUENCES ........................................................................................... 29
4.1 Physical Environment ....................................................................................................................... 29
4.1.1 Air Quality ................................................................................................................................. 29
4.1.2 Soils ........................................................................................................................................... 30
4.1.3 Water Resources and Quality..................................................................................................... 31
4.2 Biological Environment .................................................................................................................... 31
4.2.1 Vegetation.................................................................................................................................. 31
4.2.2 Wildlife ...................................................................................................................................... 32
4.2.3 Threatened and Endangered Species and Special Status Species .............................................. 33
4.3 Human Environment ......................................................................................................................... 36
4.3.1 Cultural Resources ..................................................................................................................... 36
4.3.2 Recreation .................................................................................................................................. 36
4.4 Natural Environment ......................................................................................................................... 37
4.4.2 Wilderness ................................................................................................................................. 38
4.5 Assessment of Cumulative Impacts .................................................................................................. 39
4.5.1 Air quality .................................................................................................................................. 40
4.5.2 Soils ........................................................................................................................................... 41
4.5.3 Wildlife ...................................................................................................................................... 41
4.5.4 Threatened and Endangered Species and Special Status Species (Sonoran pronghorn)............ 41
4.5.6 Wilderness Values ..................................................................................................................... 42
4.6 Indian Trust Assets............................................................................................................................ 43
4.7 Unavoidable Adverse Effects............................................................................................................ 43
4.8 Irreversible and Irretrievable Commitment of Resources ................................................................. 43
4.9 Summary of Potential Environmental Effects................................................................................... 44
ii
May 2011
5.0 CONSULTATION, COORDINATION AND DOCUMENT PREPARATION ................................. 46
6.0 REFERENCES ..................................................................................................................................... 47
List of Tables
Table 1. Proposed new and modified catchment construction ...................................................................... 3
Table 2. Estimated labor days to construct each catchment.......................................................................... 7
Table 3. Existing water catchments name and capacity .............................................................................. 16
Table 4. Species protected under the Endangered Species Act with a potential to occur in Yuma and Pima counties, Arizona .......................................................................................................................... 22
Table 5. Species protected under the Endangered Species Act and the potential impacts from the Proposed Action Alternative......................................................................................................................... 34
Table 6. Summary of environmental effects by alternative ........................................................................ 44
List of Figures
Figure 1. Location of Proposed Projects ....................................................................................................... 2
Figure 2. Schematic of a proposed Sonoran pronghorn water development ................................................ 4
Figure 3. Photo of a Sonoran pronghorn water catchment basin .................................................................. 4
Figure 4. Photo of Sonoran pronghorn at a feeder station within the pen..................................................... 5
Figure 5. Unauthorized vehicle routes documented within the CPNWR as of November 2008 ................ 10
Figure 6. No Action Alternative ................................................................................................................. 15
Figure 7. Current range of Sonoran pronghorn showing roads and railroads ............................................. 24
Figure 8. Current and historic range of Sonoran pronghorn ....................................................................... 25
Figure 9. Existing landscape character in Refuge ....................................................................................... 28
Appendices
Appendix A
AGFD Guidelines for Handling Sonoran Desert Tortoises
Appendix B
Comment Letter
Appendix C
Biological Evaluation
Appendix D
Intensive Archaeological Survey of Ten Water Catchments on the Cabeza Prieta National
Wildlife Refuge, Southwestern AZ
iii
May 2011
LIST OF ACRONYMS AGFD BE
BMGR
CAA CCP
CFR DM EA ESA °F FEP FW I
mph
OPCNM PSD PVC
MRA
NEPA SR
Refuge U.S.
U.S.C.
USAF
USFWS
Wilderness
Arizona Game and Fish Department
Biological Evaluation
Barry M. Goldwater Range
Clean Air Act
Cabeza Prieta Comprehensive Conservation Plan Wildlife Stewardship Program and
Environmental Impact Statement
Code of Federal Regulations
Department of the Interior Department Manual
Environmental Assessment
Endangered Species Act
degrees Fahrenheit
Forage Enhancement Plot
Fish and Wildlife Service Manual
Interstate
miles per hour
Organ Pipe Cactus National Monument
prevent significant deterioration of air quality
polyvinyl chloride
Minimum Requirements Analysis
National Environmental Policy Act
State Route
U
nited States
United States Code
United States Air Force
United States Fish and Wildlife Service
Arizona Desert Wilderness
iv
May 2011
1.0 PROPOSED ACTION
1.1 Introduction
The United States Fish and Wildlife Service (USFWS) is proposing to provide supplemental water and
forage for the endangered Sonoran pronghorn to meet Sonoran Pronghorn Recovery Plan and
Comprehensive Conservation Plan objectives.
The first “Narrative for Recovery Actions” statement specified in the Final Revised Sonoran Pronghorn
Recovery Plan (1998) is to “Enhance the present population of Sonoran pronghorn to reach a recovery
goal of 300 adults” and to “decrease factors that are potentially limiting population growth.” The action
statements that follow include: “Enhance Sonoran pronghorn numbers through fawn recruitment and,
increase adult and fawn survival through habitat enhancement, investigation of food plots and water
developments.”
The Cabeza Prieta Comprehensive Conservation Plan Wildlife Stewardship Program and Environmental
Impact Statement [CCP] 2007) states “The refuge will implement a program of upgrading existing
developed waters in wilderness. The upgrades will increase their water collection efficiency and capacity
while decreasing evaporation, visual intrusiveness and maintenance requirements. These improvements
should greatly reduce or eliminate the need for hauling supplemental water.” Further, the Refuge’s CCP
states “Any new waters for Sonoran pronghorn that the Sonoran pronghorn recovery team determines to
be necessary will be constructed at sites determined by consultation between the refuge and the recovery
team.”
This Environmental Assessment (EA) is being prepared to evaluate the effects associated with this
proposed action and complies with the National Environmental Policy Act (NEPA) in accordance with
Council on Environmental Quality regulations (40 Code of Federal Regulations [CFR] 1500-1509) and
Department of the Interior (516 Department Manual [DM] 8) and USFWS (550 Fish and Wildlife Service
Manual [FW] 3) policies (see Section 1.7 for a list of additional regulations with which this EA
complies). NEPA requires examination of the effects of proposed actions on the natural and human
environment.
1.2 Proposed Action
The Proposed Action is to construct five water catchments and enlarge five existing catchments to
provide reliable water sources for the Sonoran pronghorn and other wildlife species. Each catchment
would be constructed or modified to store approximately 11,000 gallons of water. This would provide a
more reliable water source and thus reduce or eliminate the need to haul water. Temporary waters and
supplemental feeding are also part of the proposed action. One existing catchment, Antelope Hills would
be abandoned and the site reclaimed. Figure 1 shows the catchment locations and Table 1 shows a
summary of the proposed catchment constructions and renovations.
The Proposed Action uses mechanized equipment (i.e. backhoe) to access the sites for excavation where
there are existing trails to the site and when substrate conditions preclude hand-digging (see Table 2)
Safety concerns would be mitigated through training and adherence to AGFD written policy.
1
May 2011
Figure 1. Location of Proposed Projects
2
May 2011
1.3 Location
The project area is located within the Cabeza Prieta National Wildlife Refuge in Pima and Yuma
Counties, Arizona (Figure 1). Approximately 93 percent of the Refuge is designated as part of the
National Wilderness Preservation System per the Arizona Desert Wilderness Act of 1990 (Public Law
101-628, HR 2570 Title 3). The proposed locations for supplemental water and forage areas would be
within the designated Wilderness portions of the Refuge.
1.3.1 Proposed New Catchments and Modification of Existing Catchments
Each catchment would consist of 24 sections of 24-inch-diameter by 20 feet PVC pipe which would result
in approximately 11,000-gallons of storage (Figure 2). A walk-in 4-foot-wide by 7-foot-long by 36 inchdeep ground-level drinking trough would be connected to the storage pipes using flexible plumbing. Up
to three collection points would be constructed for each catchment. All PVC pipe would be buried at least
1 foot beneath the surface. The top soil surface would be set aside during excavation and returned to the
surface after the storage pipe is placed in the hole. The contour of the surface would be returned as close
as possible to the original level. Diagrams of the catchments are provided in Figure 2 and a photo
showing a typical water catchment basin is shown in Figure 3.
Table 1. Proposed new and modified catchment construction
Catchment
Name
Sierra Pintas #1
Sierra Pintas #2
Sierra Pintas #3
Granite #1
Fawn Hills
Granite #2
Agua Dulce #1
Agua Dulce #2
Agua Dulce #3
Antelope Hills #1
Existing Capacity
(gallons)
3,314
3,752
1,876
5,159
2,814
0
0
0
0
0
Existing or
Proposed
Existing
Existing
Existing
Existing
Existing
Proposed
Proposed
Proposed
Proposed
Proposed
Proposed Capacity
(gallons)
11,000
11,000
11,000
11,000
11,000
11,000
11,000
11,000
11,000
11,000
1.3.2 Proposed Placement of Temporary Waters
The proposed action also includes the placement of temporary waters when recommended by the SPRT
and approved by the Refuge Manager. These waters are only proposed for times of crisis, such as periods
of extreme or prolonged water and forage shortages. These waters would consist of a small holding tank
(up to 2,000 gallons) and a 100 to 150 gallon drinking trough, and would be placed in the vicinity of
Sonoran pronghorn herds. Polyethylene flex pipe would connect the holding tank to the water trough. The
holding tanks would be draped with camouflage netting and the netting secured to the ground either by
rebar staking or by using large rocks as anchors. The drinking trough would be partially buried in the
ground to secure the trough, limit its visibility from a distance, and to reduce evaporative loss. The
3
May 2011
Figure 2. Schematic of a proposed Sonoran pronghorn water development
Figure 3. Photo of a Sonoran pronghorn water catchment basin
4
May 2011
polyethylene flex pipe from the holding tank to the trough would be buried to prevent animals from
disturbing the line and to insulate the water in the line from the summer temperatures. During periods of
high use, temporary waters would require at least weekly visits to maintain available water within the
tanks. These waters would not be permanent structures as defined under the Wilderness Act; they would
be removed after their purpose has been served.
1.3.3 Proposed Supplemental Feeding
A supplemental feeding program would be implemented during periods of poor forage production to
enhance fawn survival when recommended by the SPRT and approved by the Refuge Manager. Baled
alfalfa and pellet feed formulated for pronghorn would be transported via helicopter or by truck to the
proximity of existing waters (catchments and temporary waters) where fawns are known to be present or
periodically as needed to preserve the lives of adults in an attempt to stabilize and prevent the loss of
pronghorn groups frequenting a water source.
Supplemental feed stations would be constructed of a lumber frame with a plywood and wire platform to
hold the feed off the ground (Figure 4). Additional feed would be stored off the ground on pallets and
covered with tarps for future use. Any ground disturbance would be minimized and the soils returned to a
pre-disturbance condition to the extent possible.
Figure 4. Photo of Sonoran pronghorn at a feeder station within the pen
5
May 2011
1.4 Best Management Practices/Conservation Measures
1.4.1 Water Developments
Saguaro cacti and large trees will be avoided. Other cacti species may be salvaged and re-planted where
feasible. Photographs of each project area would be taken prior to the initiation of construction. After
construction, the area would be contoured to pre-disturbance condition and all tracks would be raked out.
The visible portions (the above-ground components) of each of these catchments would be limited to the
collection points located in adjacent runnels and the walk-in drinking trough. The life expectancy of these
catchments is 50 plus years. The first PVC water catchment was built in 1995 and the level of sediment in
the tanks was measured during 2010 and found to be insignificant (John Hervert, AGFD, personal
communication).
Materials and vehicles would be staged at a designated area such as an established public access road .A
helicopter would be used to fly in equipment, construction materials, and personnel to the catchment site.
The use of a helicopter to transport personnel and equipment would eliminate the need for multiple
vehicles to travel into the construction area and would reduce foot paths leading from authorized roads to
the catchment construction sites. An anticipated 24 to 36 helicopter trips would be required per site to
transport all of the personnel and equipment. This estimate includes the number of trips required to
transport and place the 500 lb. 20-foot by 24-inch water pipes used in the catchment systems. These pipes
would be transported one at a time and placed directly into the trench to minimize impact to the
catchment area. This would also eliminate the need for personnel to place the pipe in the trench by hand,
thereby reducing impacts to soil and vegetation at the site.
At locations that support soils suitable for hand digging (coded with an “A” in Table 2), crews of up to
20 people would use hand tools such as shovels, rakes, caliche bars, and pick axes. At locations that
support soils unsuitable for hand digging (coded with a “B” in Table 2), crews of a minimum of 10 people
would be flown to the construction site and a backhoe would be driven in from the nearest point of
existing disturbance along an existing trail. A helicopter would be used to deliver the 24-inch by 20-foot
water pipes and other large equipment. Under each scenario, personnel would be flown out by helicopter
at the end of the day and camp in a designated staging area. The backhoe would remain at the site until
construction is completed and would be driven out along the same path it came in on. The access route
and other signs of human presence would be concealed by raking out track marks, and returning the area
to preconstruction conditions. Work would be conducted outside of the pronghorn closure season (March
15 through July 31) when possible, but some emergency response actions and construction may occur
within this window.
Once these larger capacity catchments fill with water from surface runoff due to precipitation, the need
for supplemental water hauling is anticipated to be reduced considerably, if not eliminated entirely, which
would reduce or eliminate the need for periodic intrusions into the Wilderness area that are associated
with water hauling.
6
May 2011
Table 2. Estimated labor days to construct each catchment
Water Catchment Location
Alternative
Proposed
Action
A
B
Sierra
Pinta
#1A
Sierra
Pinta
#2A
Sierra
Pinta
#3A
Antelope
Hills
#1B
Agua
Dulce
#1B
Agua
Dulce
#2B
Agua
Dulce
#3A
Granite
#1B
Granite
#2B
Fawn
HillsB
34
labor
days
32
labor
days
40
labor
days
20
labor
days
20
labor
days
20
labor
days
48
labor
days
20
labor
days
20
labor
days
20
labor
days
Soil is free of compacted rock or lacks a caliche layer.
Soil is composed of compacted rock or caliche layer.
1.4.2 Supplemental Forage
Where no access via existing trail permits, up to five helicopter missions may be needed per season to
initially stock and replenish alfalfa at the selected waters, depending on the duration and timing of nonforage producing periods. During each mission, three helicopter trips per water may be needed to move
12 to 24 bales of alfalfa to each of the selected feed sites. This would equate to a possible 15 helicopter
flights per season, and the helicopter would attempt to avoid pronghorn. At waters accessible via trail, a
truck would be used to haul baled alfalfa as needed. Up to five missions may be needed per season to
initially stock and replenish alfalfa at the selected waters depending on the duration and timing of nonforage producing periods. The same amount of alfalfa (12 to 24 bales) could be transported to each site
with one to two trips by truck.
1.4.3 Additional Measures
Additional best management practices and conservation measures proposed as part of the Proposed Action to minimize impacts include: 
After construction is complete, construction personnel would return the construction area and the
access route to a preconstruction condition by raking and obscuring tire tracks and footpaths.

Mature saguaros, trees, and columnar cactus would be avoided by all construction activities.

Native vegetation would be avoided to the maximum extent possible. If cactus cannot be avoided,
transplantable specimens would be salvaged and transplanted after construction is completed.

Helicopter flight routes would be chosen to avoid areas used by pronghorn, as determined by the
most recent AGFD bi-weekly pronghorn monitoring flights and other pronghorn monitoring
efforts. Furthermore, a biologist would be present on the first flight and would scan for pronghorn
and other wildlife. If pronghorn are observed from the helicopter, helicopter overflights would be
redirected away from any pronghorn sighted and to the extent possible direct the pilot to
minimize further disturbance to pronghorn and wildlife.
7
May 2011

Helicopter flights for supplying water and supplemental feed during summer months would be
conducted during daylight hours and the flight path would avoid flying over known lesser longnose bat roosting areas (such as mine adits and known maternity colony locations).

To minimize disturbance to Sonoran pronghorn, the minimum number of vehicles would be used
and the minimum number of trips to work sites would be made to complete the job in the fastest
and most efficient manner as authorized in the MRA decision.

The Refuge biologist would accompany Refuge and AGFD vehicles and equipment to each staging area. 
Vehicle operators would be trained to recognize pronghorn. If pronghorn are sighted within one
mile of the project site or any access road to the site by the Refuge biologist or vehicle operators,
the vehicles involved would initially stop to allow the pronghorn to move away and to reduce
disturbance to the extent possible. Once the pronghorn have moved away from line of sight or
greater than one mile of the vehicle or project site, depending on terrain, vehicles would proceed
at 15 mph for the first mile and then resume normal speeds (25 mph).

To minimize disturbance to Sonoran Desert tortoises project activities, to the extent possible,
would be scheduled when tortoises are inactive (typically November 1 to March 1). Additionally,
the AGFD Guidelines for Handling Sonoran Desert Tortoises Encountered on Development
Projects (Appendix A) would be followed should any tortoises be encountered.
To minimize disturbance to Sonoran Desert tortoises and their habitat, a desert tortoise awareness
education program would be presented to all construction personnel. The program would include
a briefing of: 1) the legal and sensitive status of the tortoise; 2 tortoise life history and ecology; 3)
mitigation measures designed to reduce adverse effects to tortoises; and 4) protocols to follow if a
tortoise is encountered.
1.5 Background
Sonoran pronghorn were one of the first species declared endangered; they were listed in the first
endangered species legislation—the Endangered Species Preservation Act of 1966—and subsequently
included in a list of endangered species published in 1967, the Endangered Species Conservation Act of
1970, and again under the Endangered Species Act of 1973 (ESA). The Refuge was designated as the lead
office for recovery of the Sonoran pronghorn in 1988 by the USFWS Southwest Regional Director, thus
elevating its status as a refuge management priority. The Sonoran Pronghorn Recovery Team (SPRT)
consists of one or more representatives from each agency that has a mandate to protect the species and/or
manage lands inhabited by pronghorns both currently and historically. SPRT currently consists of the
USFWS, Arizona Game and Fish Department (AGFD), Commission of Ecology and Sustainable
Development for the State of Sonora (CEDES) group, Natural Commission for Protected Natural Areas
(CONANP), US Air Force (Luke Air Force Base), US Marine Corps, (Marine Corps Air Station Yuma),
Bureau of Land Management (BLM), National Park Service (NPS), and a representative from the Arizona
State University. SPRT also includes veterinary staff and representatives from regional zoos including
Phoenix Zoo and Los Angeles Zoo. The original SPRT was organized in the early 1980s to develop the
1982 Sonoran Pronghorn Recovery Plan, and the current SPRT was formed in 1999.
Presently, Sonoran pronghorn occupy approximately 8 percent of their historic range, which originally
included most of southwestern Arizona, an equally large area within northwestern Sonora, Mexico and
8
May 2011
portions of southeastern California. Approximately 100 Sonoran pronghorn survive in the wild within the
Arizona portion of their current range. An additional 70 Sonoran pronghorn are managed as part of a
semi-captive herd on the Refuge. Their current range in the US is limited to approximately 1.6 million
acres, found almost entirely within the Refuge, Barry M. Goldwater Range (BMGR), and Organ Pipe
Cactus National Monument (OPCNM).
Sonoran pronghorn’s access to portions of suitable habitat within their historic range has been eliminated
by the construction of major highways, fences, and water canals. They have been unable to access the
Gila and Rio Sonoyta rivers since the construction of Interstate 8 (I-8), State Route 85 (SR 85), Mexican
Highway 2, and Mexican Highway 8. Only one naturally occurring perennial water source, Quitoboquito
Spring, exists within their current range in the US. This spring is located on OPCNM in an area of high
illegal border crossings, and adjacent to a busy Mexican highway. Pronghorn have never been
documented at the spring, but have been documented within 2 miles of it (Tim Tibbitts, OCPNM,
personal communication).
The pronghorn’s access to other areas of their current range are presumed to have been and are currently
being impacted by US/Mexico border related activities (e.g., smuggling), associated law enforcement
efforts, and recreation activities. All of the valley habitats including the entire pronghorn range within the
Refuge have been heavily impacted by border related activities (Figure 5). Within the wilderness area of
the Refuge nearly 8000 miles of illegal vehicle routes were recently delineated. The data was derived
from an analysis of fall, 2008 true color, high resolution (30 cm ground sample distance) imagery
obtained in cooperation with the Department of Defense. The network of illegal vehicle routes within
Refuge wilderness is both extensive and locally severe. Vehicle routes were classified into four categories
as defined below.
Class 1 - Tire tread impressions in soil, or soil berms built up around tire tracks. Undisturbed
soil and/or vegetation growing between tracks
Class 2 – Multiple parallel Class 1 road tracks with three or more crossings of tracks within 100
meters
Class 3 - Soil berms built up around tire tracks. Disturbed soil and no vegetation between tracks
Class 4 – Multiple parallel Class 3 road tracks with three or more crossings of tracks within 100
meters
Nearly 99% of the illegal vehicle routes identified were classified as Class 1 (Steve Barclay, USFWS,
personal communication). A detailed analysis is currently underway to examine the effects of human
activity on Sonoran pronghorn (Jim Atkinson, USFWS, personal communication).
The Sonoran pronghorn subpopulation in the U.S. appears to be most sensitive to the number of fawns
that survive to adulthood. Approximately 35 fawns for every 100 adult females need to be recruited each
year in order for the U.S. subpopulation to grow (John Hervert, AGFD, personal communication). In
response to the prolonged 2002 drought that nearly extirpated the remaining U.S. population of Sonoran
pronghorn, the USFWS and its cooperating agency partners through the Sonoran Pronghorn Recovery
Team (SPRT), have developed five forage enhancement (irrigation) plots (FEPs) in the non wilderness
area of the refuge (three) and within the BMGR (two) in an attempt to enhance fawn survival. Each FEP
9
May 2011
Figure 5. Unauthorized vehicle routes documented within the CPNWR as of November 2008
10
May2011
includes a water source that is maintained (filled) during periodic irrigation cycles throughout the year.
Additionally, there are three other water sources for Sonoran pronghorn within the non wilderness area of
the refuge and five water sources for pronghorn within the BMGR. The topography and associated plant
community within the non-wilderness area of the refuge (Child’s Valley) offers better concealment for
smugglers than the broadly open valley habitats to the west that lie within designated Wilderness.
Consequently, the Child’s Valley is both frequently and heavily used by smugglers which may be
offsetting the Refuge’s attempts to establish and stabilize pronghorn within the non-wilderness area (Jim
Atkinson, USFWS, personal communication).
Additionally, the USFWS developed six small storage capacity water catchments between 2004 and 2007
within the wilderness area of the Refuge. These catchments were strategically placed within core current
pronghorn range according to established pronghorn use patterns as determined through radio telemetry
data. Pronghorn have been observed routinely using these existing catchments and the USFWS believes
they are essential components of pronghorn recovery.
Sonoran pronghorn forage on cactus fruits, such as chain fruit cholla in hot, dry seasons to help meet
metabolic water requirements when free standing water sources are not available. Fox et al. (2000)
suggested Sonoran pronghorn water intake from forage alone was not adequate to meet minimum water
requirements (0.5 to 0.9 gallons per animal per day). In particular, availability of freestanding water
contributes directly to adult and fawn survival as the use of water sources by pronghorn peaks between
May and August—the hottest time of the year, when water is most scarce. AGFD observations have
shown increases in fawn mortality after 30 to 60 days with no rain. Mortality is likely due to the forage
losing its succulence and nutritional quality as it dries out (Jill Bright, AGFD, personal communication,
May 24, 2010).
When the captive breeding pen was established in 2004, high quality alfalfa hay was provided to the
pronghorn as supplemental feed beginning in 2005. The pronghorn in the pen eventually learned to feed
on the alfalfa.
Sonoran pronghorn in the captive breeding pen increase their intake of alfalfa when rain is absent more
than 60 days. Subsequent observations have shown that wild pronghorn will use alfalfa hay as a food
source; particularly once wild pronghorn herds intermix with released captive pronghorn that have
learned to eat alfalfa hay (Jim Atkinson, CPNWR, personal communication, October 19, 2010). Use of
supplemental feed as a management tool may be a key factor to decreasing pronghorn mortality during
prolonged drought conditions when forage conditions are poor.
Water hauling to fill empty or nearly empty water catchments has been ongoing since 2003 due to
persistent drought conditions and low storage capacity of some of the water catchments constructed for
Sonoran pronghorn. Most water hauling occurs during late spring and summer. Water hauling is done by
truck or helicopter depending upon the location. Because temperatures during this time period tend to be
greater than 90 degrees Fahrenheit (oF), helicopter lifting capacity is limited thus requiring more flights to
supply enough water to support pronghorn. The USFWS has found that larger capacity catchments (such
as Antelope Parabolic near the Aqua Dulce Range) rarely, if ever, require supplemental water hauling
operations.
11
May 2011
1.6 Purpose of Action
The purpose of the Proposed Action is to contribute to the recovery of Sonoran pronghorn, a Federally
listed endangered species, pursuant to the ESA, by implementing management actions to limit loss of
Sonoran pronghorn, reduce fawn mortality and to stabilize the population. Reliable water sources and,
when necessary, supplemental feed are critical components to achieve these purposes. Goal 1, Objective 2
of the CCP states that the refuge will “continue to ensure that reliable sources of free water are available
in at least 22 locations within the range of the Sonoran pronghorn.” The strategies listed for
accomplishing these objectives include: “Survey Sonoran pronghorn habitat throughout the refuge to
identify potential sites for upgraded developed waters similar to the redeveloped water at Antelope Tank
and, develop additional waters at suitable sites in Sonoran pronghorn habitat, should the Sonoran
pronghorn recovery team determine they are necessary”. Recovery actions within the Final Revised
Sonoran Pronghorn Recovery Plan (1998) specify to “Enhance the present population of Sonoran
pronghorn to reach a recovery goal of 300 adults” and to “decrease factors that are potentially limiting
population growth.”
1.7 Need for Action
The Proposed Action is necessary to stabilize the Sonoran pronghorn population and meet recovery goals.
Because rainfall in the arid Southwest is typically very sporadic with long periods of no rain, low capacity
water storage facilities are often inadequate to store enough water to provide water until the next rain
event. To ensure water is permanently available for pronghorn, the water storage capacity of the identified
waters must be enlarged. The storage capacity of the existing water catchments for Sonoran pronghorn on
the Refuge ranges from 1,870 to 5,160 gallons, which is not large enough to prevent the catchments from
going dry between the infrequent rains. In the absence of rain, the smaller capacity catchments can go dry
within six months and the largest can go dry within one year. Thus, the existing water catchments require
replenishment by helicopter water-hauling missions primarily during periods critical to the needs of
pronghorn. Only one of these catchments (Fawn Hills) is accessible via water truck. The most sensitive
period tends to be between May and July when fawns are present and temperatures exceed 90°F (personal
communication, Jill Bright, AGFD May 24, 2010).Current water hauling operations usually take place in
the late spring and early summer months after the winter rainy season. Because higher temperatures limit
helicopter lifting capacity, multiple trips are presently needed during a hauling operation to supply
enough water to support pronghorn. Increased capacity in water catchments would assist in reducing or
eliminating the need to haul water.
Providing water for pronghorn is a widespread, accepted management practice (O’Gara and Yoakum
1992, Yoakum 1994). Studies have documented Sonoran pronghorns’ use of free-standing water sources
(Hervert et al. 2000, Morgart et al. 2005) and provided evidence that these water sources benefit the
Sonoran pronghorn (Hervert et al. 2000, Bright and Hervert 2005).
The availability of free-standing water to pronghorn is vital, particularly during drought periods when
preformed water (i.e., water bound in plant tissue) is scarce (Fox et al. 1997). Access to water is essential
for digestion of food and for cooling the body (Schmidt-Nielson 1964). Drinking free-standing water also
enables pronghorn to consume and use forage of higher nutritional quality than chain fruit cholla (Hervert
personal communication 2010). Existing wildlife water storage capacity is insufficient to provide water
throughout dry periods without supplemental water hauling. New, large-capacity water catchments are
needed on the Refuge to provide reliable water sources for pronghorn within movement corridors and to
12
May 2011
offset the loss of habitat that is no longer accessible. The placement of additional temporary waters may
be needed as an offsetting measure for pronghorn that now avoid preferred habitats or established water
catchments due to continued human intrusion.
The Refuge may also need to provide supplemental feed at all waters as needed during periods of poor
forage production as an offsetting measure to minimize pronghorn loss that may occur otherwise,
particularly among fawns. The need for supplemental feed would be determined by the following criteria:
(1) whether or not pronghorn with fawns were present in the vicinity of a water catchment and (2) upon
the condition of and distance to available forage during critical periods. A population viability analysis
(PVA) workshop conducted in 1996 when populations estimates for Sonoran pronghorn ranged from 130
to 160, estimated a 23-percent probability of extinction within the next 100 years. The risk of extinction
rose considerably whenever the population declined below 100 individuals. Further, the PVA indicated
that the current Sonoran pronghorn population is most sensitive to fawn survival rates, which underscores
the importance of any management action that have the potential to increase fawn survival in the least
(Hosack et al. 2002).
1.8 Decision to be Made
This EA describes the environmental effects of the alternatives evaluated and provides information to
help the USFWS fully consider the potential environmental effects and any proposed mitigation. Using
the analysis in this EA, the USFWS will decide whether there would be significant environmental effects
associated with the Proposed Action that would require the preparation of an environmental impact
statement or whether the Proposed Action can proceed.
1.9 Regulatory Compliance
This EA was prepared by the USFWS, in coordination with the AGFD, and represents compliance with
applicable Federal statutes, regulations, Executive Orders, and other compliance documents, including the
following:

Administrative Procedures Act (5 United States Code [U.S.C.] 551-559, 701-706, and 801-808)
as amended

American Indian Religious Freedom Act of 1978 (42 U.S.C. 1996)

Antiquities Act of 1906 (16 U.S.C. 431-433)

Archaeological Resources Protection Act of 1979 (16 U.S.C. 470)

Bald Eagle Protection Act (16 U.S.C. 668-668d) as amended

Clean Air Act of 1972, as amended (42 U.S.C. 7401 et seq.)

Clean Water Act of 1972, as amended (33 U.S.C. 1251 et seq.)

Endangered Species Act of 1973, (ESA) as amended (16 U.S.C. 1531 et seq.)

Executive Order 12898, Federal Action Alternatives to Address Environmental Justice in
Minority Populations and Low Income Populations, 1994.

Executive Order 13112, Invasive Species (issued in February 1999)

Fish and Wildlife Coordination Act of 1958, as amended (16 U.S.C. 661 et seq.)

Fish and Wildlife Improvement Act of 1978 (16 U.S.C. 7421)
13
May 2011

Floodplain Management (Executive Order 11988)

Migratory Bird Treaty Act (16 U.S.C. 703-712) as amended

National Refuge System Administration Act of 1966 (16 U.S.C. 668dd-668ee) as amended

National Environmental Policy Act (NEPA) of 1969 (42 U.S.C. 4321 et seq.) as amended

Regulations for Implementing the Procedural Provisions of NEPA (40 CFR 1500 et seq.)

National Historic Preservation Act of 1966 (16 U.S.C. 470 et seq.) as amended

Native American Graves Protection and Repatriation Act of 1990 (25 U.S.C. 3001 et seq.)

Protection and Enhancement of the Cultural Environment (Executive Order 11593)

Protection of Wetlands (Executive Order 11990)

National Pollutant Discharge Elimination System (33 U.S.C. 1251 et seq.) as amended

Soil and Water Conservation Act of 1977 (16 U.S.C. 2001-2009) as amended

Wilderness Act 1964

The Arizona Desert Wilderness Act of 1990 (HR 2570 Title 3)
Further, this EA reflects compliance with applicable State of Arizona and local regulations, statutes,
policies, and standards for conserving the environment and environmental resources such as water and air
quality, endangered plants and animals, and cultural resources.
1.10 Scoping/Public Involvement and Issues Identified
On June 17 2010, the USFWS announced its intent to prepare an EA on the alternatives under
consideration for the redevelopment of water catchments, construction of new water catchments, and
provisions for temporary watering and supplemental feed on the Refuge. A 30-day scoping period from
June 17, 2010, through July 19, 2010, was established under that notice. The USFWS provided a news
release and sent out 27 letters and emails to potential interested parties announcing the initial scoping
period for development of this EA. Seven of the scoping letters were mailed to local (southern Arizona)
tribes. The announcement was posted on the Refuge website.
During the scoping period, the USFWS received one response letter with comments that were considered
as part of this analysis. The response is included in Appendix B along with the list of agencies,
individuals, and organizations that were provided scoping letters. The commenter who responded during
the 30-day scoping period was supportive of the project and inquired if the USFWS had also considered a
predator management plan for the pronghorn. A predator management plan is considered to be outside of
the scope of this document. No additional issues were identified that would cause the development of
additional alternatives.
2.0 ALTERNATIVES
2.1 No Action Alternative
Under the No Action Alternative, current management direction would continue, which would maintain
the current program of hauling water to the existing catchments (Table 3 and Figure 6) when dry or nearly
14
May 2011
Figure 6. No Action Alternative
15
May 2011
dry and repairing the catchments (e.g., simple maintenance activities such as cleaning troughs and
collection screens) as problems occur.
Table 3. Existing water catchments name and capacity
Catchment Name
Antelope Hills
Granite #1
Fawn Hills
Sierra Pintas #1
Sierra Pintas #2
Sierra Pintas #3
Existing Capacity
2,814
5,159
2,814
3,314
3,752
1,876
2.1.1 Water Catchments
The six existing catchments have a water storage capacity ranging from 1,876 to 5,159 gallons. None of
these catchments is large enough to maintain a standing water supply during long periods without rain
(six to twelve months without precipitation). One of the six catchments (Antelope Hills) has never been
fully functional due to a perennial leak and was not optimally located for pronghorn when it was
originally installed. The existing catchments are constructed of one or more rows of buried 20-foot by 18
or 24-inch polyvinyl chloride (PVC) pipe that gravity feeds water into a ground level, 4-foot-wide by 7
foot-long by 30-inch-deep walk-in trough. Catchments have at least one collection point that consists of a
small dam in a nearby runnel that functions to channel surface runoff from rainfall into a 4- or 6-inch
PVC pipe that in turn feeds into the buried rows of storage pipe. Additionally, covers have been added to
the trough to minimize water loss through evaporation. Water hauling missions via helicopter to the
existing catchments are required to maintain a water supply during periods critical to the needs of
pronghorn. Water retention rates within the existing catchments are variable due to the differing storage
capacities of each. The most influential factor affecting retention rates is the degree of use that the
catchments receive from pronghorn. Three catchments went dry or were nearly dry during the prolonged
2009 drought.
2.1.2 Temporary Water and Supplemental Feeding
Emergency placement of temporary waters has not been used as a management tool to date on the Refuge,
although it could occur. Placement of temporary waters has occurred on the BMGR and on OCPNM. The
placement of temporary waters and use of supplemental feeding in emergency situations could occur
under existing USFWS management guidelines. Temporary waters have limited storage capacity and
would require frequent trips for maintenance and water recharge. Supplemental feeding also has been
used for Sonoran pronghorn on the Refuge, the BMGR and is planned for OCPNM. It has been used
experimentally on the BMGR since 2009 in an effort to draw pronghorn away from actively used targets
and was used in 2009 on the Refuge following pronghorn releases, but is not regularly occurring within
the Refuge. Supplemental feeding is planned for ORPI and will be done in spring-summer 2011. This is
being done in part as required mitigation for the SBInet Ajo-1 project. But also as a pro-active emergency
recovery action, needed because of the combined impacts of border activities and drought (Tim Tibbitts,
NPS, personal communication).
16
May 2011
The only supplemental feeding on the Refuge since the initial Bermuda grass hay experiment has been at
the Charlie Bell forage enhancement plot (which was established to increase fawn survival) and in the
vicinity of the captive breeding pen following pronghorn releases in 2009. Depending on the duration and
timing of non-forage producing periods, up to five helicopter missions may be needed per season to
initially stock and replenish alfalfa at selected catchments. During each mission, three helicopter trips per
catchment may be needed to move 12 to 24 bales of alfalfa to each of the selected feed sites. This would
equate to a possible 15 helicopter flights per season.
The No Action Alternative would not fully meet the Purpose and Need of this project. The six existing
catchments currently contribute to the recovery of Sonoran pronghorn and are necessary to stabilize the
population. However, the No Action Alternative would not provide sufficient perennially available water
and forage resources to maintain the population over time or in periods of severe or extended drought.
Continued use of low-water-capacity catchments would result in continued, intrusive, and costly
maintenance trips. Use of temporary water catchments on an emergency basis alone, would not provide a
long-term solution and meet the need to stabilize the Sonoran pronghorn population with the ultimate
purpose of contributing to the recovery of the species. Standardizing a proactive response to recurring
environmental conditions, such as extreme drought, or management issues, such as the failure of a
permanent water development, through an approved plan is generally superior to reactive crisis
management. To be of maximum population value and efficiency in management actions, temporary
waters would have to be placed in strategic locations and be functional prior to any water-related
movements from the target group or individual Sonoran pronghorn. If any delay occurs in providing a
temporary water source to a specific area occupied by Sonoran pronghorn at the time a decision is made,
water-related movements may occur and result in the temporary water not being found and used by
Sonoran pronghorn. An established and vetted response to Sonoran pronghorn survival of environmental
conditions would ensure that management actions are consistent and that the potential adverse impacts of
these actions have been analyzed and avoided, minimized, or mitigated. The No Action Alternative is
included in the EA as a basis for comparison for the Proposed Action.
2.2 Alternatives Considered But Dismissed From Detailed Analysis
An alternative consisting of development of an implementation plan describing the placement of
temporary waters and supplemental feed during a time of crisis was also considered. Placement of
temporary waters and use of supplemental feed is an authorized activity under existing management
guidelines in emergency conditions. However, this alternative would provide management guidelines for
placement of such temporary waters and use of supplemental feed and would avoid placement of any new
permanent structures within Wilderness. Under this alternative, temporary water tanks would be placed in
the vicinity of Sonoran pronghorn herds in crisis. The temporary waters would consist of a small holding
tank (up to 2,000 gallons) and a 100 to 150 gallon water trough. Polyethylene flex pipe would connect the
holding tank to the water trough. The holding tanks would be draped with camouflage netting and the
netting secured to the ground either by rebar staking or by using large rocks as anchors. The trough would
be partially buried in the ground to secure the tank, limit its visibility from a distance, and to reduce
evaporative loss. The feeder line from the holding tank to the trough would be buried to prevent animals
from disturbing the line and to insulate the water in the line from the summer temperatures.
This alternative would require at least bi-weekly visits during periods of heavy use to maintain available
water within the tanks and to provide supplemental feed to enhance fawn survival. It is important to note
17
May 2011
that this alternative as a stand alone requires repeated servicing by 1,500 to 2,000 gallon water trucks,
with resulting impacts on unimproved dirt roads through the refuge. If the tanks are placed away from
established legal roads, access by water trucks would establish new, heavily-impacted dirt roads to the
tanks (Tim Tibbitts, OCPNM, personal communication).
These structures would not be permanent structures as defined under the Wilderness Act; they would be
removed within one year. The use of temporary waters would only provide resources to a few animals;
herd sizes are rarely more than 5 to 7 pronghorn at the most in mid-summer.
Supplemental feed stations would consist of a lumber frame with a plywood and wire platform to hold the
feed off the ground. Additional feed would be stored off the ground on pallets and covered with tarps for
future use. Any ground disturbance would be minimized and the soils returned to a pre-disturbance
condition to the extent possible.
Use of temporary waters to stabilize the Sonoran pronghorn population would be less than ideal. Once
supplemental water sources are placed, it takes time for Sonoran pronghorn to find the water and become
habituated to use of the water source. In an emergency situation, temporary water sources would be
placed in a strategic locations and would likely be found and used by nearby Sonoran pronghorn;
however, the number of Sonoran pronghorn that benefit would be limited and the benefit would be short
term. Temporary waters would be relatively small and would require frequent trips to the location for
maintenance and refilling. Human intrusion can disturb Sonoran pronghorn using the water source and
may further limit the effectiveness of the measure.
This alternative would not fully meet the Purpose and Need. It would not provide substantive advantages
when compared to the No Action or Proposed Action Alternatives and was dropped from consideration.
3.0 AFFECTED ENVIRONMENT
This chapter describes the present environment (i.e., affected environment) in the project area within the
Refuge. Based on geographic context, preliminary research, and scoping comments, the following
resources would not be impacted by the No Action or Proposed Action Alternatives and are not addressed
in the EA: Land Ownership/Jurisdiction/Use, Minerals and Mining, Prime and Unique Farmland, Sole
Source Aquifers, Wetland and Riparian Areas, Noise, Hazardous Materials, Title VI/Environmental
Justice, and Social and Economic Considerations. No person or group of people would experience a
disproportionate share of environmental consequences as a result of implementation of either the
Proposed Action or the No Action Alternatives.
3.1 Physical Environment
The Refuge is one of the largest Wilderness area managed by the USFWS. The Refuge is located adjacent
to the OPCNM, the BMGR, the BLM, and is near to lands held by the Tohono O’odham Nation, and
Pinacate Biosphere Reserve in Mexico. These areas combine to create a vast area of undeveloped Sonoran
desert.
18
May 2011
The Refuge is located in the Sonoran region of the Basin and Range Province of North America, an
extensive system of mountains separated by valleys. Elevations on the Refuge range from 600 feet mean
sea level (msl) in the San Cristobal Valley to 3,293 feet msl in the Growler Mountains. The geology of
the Refuge is primarily basalts and granite, with sedimentary material dominating drainage corridors
throughout the Refuge. The topography of the Refuge includes broad valleys and basins between abrupt,
narrow mountain ranges. Runoff from the mountains drains northward into the Gila River, westward to
the Colorado River, and finally southward to the Gulf of California. Three large desert playas or “dry
lakes” have formed on the Refuge in areas that do not have an outlet for draining water.
3.1.1 Air Quality
The Refuge is located within an attainment area for air quality and currently meets federal and state
standards, with the exception of the 24-hour suspended particulate standard, which could be exceeded
during days with high winds (USFWS 2006). The Clean Air Act (CAA) includes measures to prevent
significant deterioration (PSD) of air quality in areas where air quality is better than the national standards
established by the US Environmental Protection Agency (EPA) to protect public health and welfare. One
of the express purposes of the PSD program is “to preserve, protect, and enhance the air quality in
national parks, national wilderness areas, national monuments, national seashores, and other areas of
special natural, recreational, scenic, or historic value.” In general, “clean air areas” are protected through
ceilings on the additional amounts of certain air pollutants over a baseline level. The PSD increment
amounts vary based on the area’s classification.
Congress gave the greatest degree of air quality protection to certain national parks and Wilderness areas.
These “Class I” areas are national parks or national Wilderness areas that were designated as of August 7,
1977, and that are greater than 6,000 acres (for parks) or 5,000 acres (for Wilderness). Only a small
amount of new pollution is allowed in these Class I areas. All other clean air regions are designated Class
II areas with moderate pollution increases allowed, unless an area is redesignated by a state or tribe. The
Wilderness portions of the Refuge are located within an area designated as Class II.
3.1.2 Soils
Soils on the Refuge are classified as “hyper thermic” (very hot) and arid. Steeper mountain areas within
the Refuge generally do not have soil, while the more gradual mountain slopes support a shallow layer of
coarse soil. Alluvial fans, bajadas and stream channels on the Refuge support coarse grained deposits.
Fine grain deposits of clay and silts occur in playas on the Refuge while dunes consisting of wind-blown
sand are found in the valleys. Most of the soil is high in salts.
According to the CCP, two soil-related formations occur on the Refuge that are sensitive to disturbance:
cryptogamic soil crusts and desert pavement (USFWS 2006). Cryptogamic soil crusts occur widely on
valley floors in the Refuge. These tiny, black, irregularly raised pedestals in the sand are self-sustaining
biological communities essential to the ecology of arid lands. Cryptogamic soils are fragile and very
susceptible to damage from trampling and compaction. Desert pavement also occurs in the Refuge. Desert
pavement is a layer of coarse gravel and cobble-size material that occurs in the surface of the older
alluvial fans. When the pavement layer is disturbed, the surface soils become more susceptible to erosion.
Desert varnish, a mineralized coating, may also occur on the desert pavement.
19
May 2011
3.1.3 Water Resources and Quality
Natural Surface Waters
The Refuge lies within the Colorado River Basin, and ground water and surface runoff generally flows
northwest toward the Gila River. No perennial water bodies exist on the Refuge, and the supply of surface
water is scarce, varying with the seasons. All streams within the Refuge are ephemeral, flowing only
during or after rains. Surface runoff rapidly evaporates and infiltrates into the ground. The largest surface
water area is the ephemeral Las Playas. Smaller surface water areas include Dos Playas and Pinta Playa.
These playas occasionally hold water for a few days after a very heavy rain.
Natural tinajas occur in the mountain ranges throughout the Refuge. A tinaja is a hole or depression in the
rock formed by scouring water that holds water for a varying length of time after rains. Many of these
natural water sources on the Refuge have been modified to increase the volume of water stored after
storm events. Waters such as Heart Tank, Buckhorn Tank, Cabeza Prieta Tanks, and Agua Dolce Springs
are examples of natural waters that have been modified for use as water sources, principally for bighorn
sheep.
Developed Waters
According to the CCP, as of 2006, there were 34 operational developed wildlife waters on the Refuge, of
which 27 are located within the Wilderness area. Several additional wells and livestock waters were
developed by early ranchers but are now inoperable either due to sand/salt intrusion or damage to the
wells. When Refuge personnel refill existing developed water catchments, the water is generally obtained
from public water sources in the town of Ajo, Arizona. Water in Ajo is drawn from a deep well and is
treated by Ajo Improvement Company. The treated water is provided to the public by Ajo Domestic
Water Improvement District and Ajo Improvement Company and Arizona Water Company-Ajo. The
2009 Consumer Confidence Report for municipal water found no water quality violations and no public
notifications during the year.
3.2 Biological Environment
Biological resources include plant and animal species and the vegetative communities within which they
occur. A Biological Evaluation (BE) was prepared for the project that includes a more detailed description
of plant and animal species occurring in the project area (Appendix C). The following discussion of the
affected environment for biological resources addresses the plant and animal communities within the
Refuge where the Proposed Action would occur. These communities include the vegetative associations
and the habitat they provide for wildlife species.
3.2.1 Vegetative Communities
The project area is located in the Lower Colorado River Valley Subdivision of the Sonoran Desertscrub
Biome (Turner and Brown 1994). The plant species that inhabit this area are adapted to dry, desert
environments. Tree species include western honey mesquite, ironwood, blue palo verde, and Smoketree.
Additional species that are only found in washes include desert willow, Chuparosa, canyon ragweed,
desert honeysuckle, catclaw acacia, Burrobrush, and desert broom. In dryer and more barren upland areas
the more common desert pavement plants are wooly plantain, creosotebush, white bursage, ocotillo,
20
May 2011
brittlebush, foothill palo verde, and saguaro. A number of cacti are commonly found in this biome
subdivision. They include silver cholla, diamond cholla, teddy bear cholla, chainfruit cholla, Englemann
hedgehog, and fishhook barrel cactus.
3.2.2 Wildlife
Large mammals that occur in the project area include desert bighorn sheep, desert mule deer, collared
peccary and Sonoran pronghorn. Other large mammals include the mountain lion, bobcat, and coyote.
Birds typically found within this habitat include turkey vulture, red-tailed hawk, Gambel’s quail, whitewinged dove, lesser nighthawk, Gila woodpecker, ash-throated flycatcher, loggerhead shrike, horned lark,
verdin, rock wren, curve-billed thrasher, cactus wren, phainopepla, and black-throated sparrow.
The desert in Arizona’s southwest is considered a “hot spot” for reptile species, hosting numerous species
of lizards and snakes. Reptiles occurring in the Refuge include the side-blotched lizard, tiger whiptail,
desert horned lizard, desert iguana, zebra-tailed lizard, coachwhip snake, Sonoran gophersnake, longnosed snake, desert patch-nosed snake, western diamond-backed rattlesnake, Mohave rattlesnake, rosy
boa, and sidewinder.
3.2.3 Threatened and Endangered Species and Other Special Status Species
Species federally listed as threatened or endangered, or proposed for such listing, have specific
protections under the ESA. Section 9 of the ESA prohibits “take” of a listed species. Section 10 of the
ESA allows for exemptions to the take prohibition, based on incidental take statements issued in
accordance with Biological Opinions or other authorized permits. Section 7 of the ESA requires a federal
agency to consult with the USFWS if the agency determines that any proposed action may affect a listed
species.
Species that may occur within the project area are analyzed in detail in the BE (Appendix C). A summary
of species protected under the ESA that have a potential to occur in Yuma and Pima counties is shown in
Table 4. The BE determined the project area supports suitable habitat for two species listed as endangered
and one listed as a candidate under the ESA: Sonoran pronghorn (Antilocapra americana sonoriensis)
and lesser long-nosed bat (Leptonycteris curasoae yerbabuenae, LLNB) and the Sonoran population of
the desert tortoise (Gopherus agassizii). Information from the BE regarding these species is summarized
below. The project area does not support any designated or proposed critical habitat. No additional
analysis is conducted for those species that may occur on the BMGR as transients or otherwise may be
present in the general project vicinity or county but for which suitable habitat is not present in the project
area.
Lesser Long-nosed Bat
The lesser long-nosed bat (LLNB) is listed as an endangered species and identified as a Wildlife Species
of Special Concern in Arizona (AGFD 2003). Their known range extends from extreme southwestern
New Mexico and southeastern Arizona north to the Phoenix area, west to the Agua Dulce Mountains on
the Refuge, south through western Mexico (Cockrum and Petryszyn 1991), and possibly to El Salvador
(Spicer 1988). This species resides in Arizona during summer months within desert grasslands and
scrubland up to the edge of oak woodland (Hoffmeister 1986, Hayward and Cockrum 1971). LLNB begin
21
May 2011
Table 4. Species protected under the Endangered Species Act with a potential to occur in Yuma and
Pima counties, Arizona
Common Name
Scientific Name
ESA Status
PLANTS
Acuna cactus
Gooddings onion
Huachuca water umbel
Kearney’s blue star
Nichol Turk's head cactus
Pima pineapple cactus
Echinomastus erectocentrus var. acunensis
Allium gooddingii
Lilaeopsis schaffneriana ssp. recurva
Amsonia kearneyana
Echinocactus horizonthalonius var. nicholii
Coryphantha scheeri var. robustispina
C
CA
E
E
E
E
INVERTEBRATES
San Xavier talussnail
Sonorella eremite
CA
REPTILES AND AMPHIBIANS
Chiricahua leopard frog
Desert tortoise, Sonoran population
Northern Mexican gartersnake
Sonoyta mud turtle
Tucson shovel-nosed snake
Lithobates [Rana] chiricahuensis
Gopherus agassizii
Thamnophis eques megalops
Kinosternon sonoriense longifemorale
Chionactis occipitalis klauber
T
C
C
C
C
FISH
Desert pupfish
Quitobaquito pupfish
Gila chub
Razorback sucker
Gila topminnow
Cyprinodon macularius
Cyprinodon eremus
Gila intermedia
Xyrauchen texanus
Poeciliopsis occidentalis occidentalis
E
E
E
E
E
BIRDS
Bald eagle
California least tern
Masked bobwhite
Mountain plover
Mexican spotted owl
Southwestern willow flycatcher
Yellow-billed cuckoo
Yuma clapper rail
Haliaeetus leucocephalus
Sterna antillarum browni
Colinus virginianus ridgewayi
Charadrius montanus
Strix occidentalis lucida
Empidonax traillii extimus
Coccyzus americanus
Rallus longirostris yumanensis
T
E
E
PT
T
E
C
E
MAMMALS
Jaguar
Lesser long-nosed bat
Ocelot
Sonoran pronghorn
Panthera onca
Leptonycteris curasoae yerbabuenae
Leopardus (=Felis) pardalis
Antilocapra americana sonoriensis
E
E
E
E
Source: USFWS list of threatened, endangered, proposed, and candidate species occurring in Yuma and Pima Counties, < http://arizonaes.fws.gov/>, accessed September 7, 2010. Status Definitions: ESA = Endangered Species Act, E = Endangered, T = Threatened, PT = Proposed Threatened, C = Candidate, CA = Conservation Agreement Cabeza Prieta National Wildlife Refuge
22
May 2011
migration into Arizona in early April and congregate in maternity colonies. LLNB migrate south in the
fall, leaving Arizona by early October (Hayward and Cockrum 1971).There is an established maternity
colony of 5,000 female lesser long-nosed bats in the Growler Mountains on the Refuge. A large colony
(25,000 to 40,000 females) is present in the vicinity of the Ajo Range in OPCNM (Hall et al. 2001). The
bats are also known from the Agua Dulce Mountains in the southeast corner of the Refuge (Cockrum and
Petryszyn 1991).
Sonoran Pronghorn
The Sonoran pronghorn is listed as endangered under the ESA (32 Federal Register 4001; 11 March
1967) without designation of critical habitat. The Refuge comprises a substantial portion of the total
occupied range of this animal. Sonoran pronghorn are the smallest and palest pronghorn subspecies, and
are proportionately long-legged and small-bodied. The female’s horns, if she has any, do not develop until
her second year and their growth is irregular. The sheaths rarely exceed three or four inches in length.
Prongs are mostly absent in females (Brown and Ockenfels 2007.) Males have horns with a single prong
projecting forward, and their horns are larger than the females’. Pronghorns are the fastest land mammals
in North America; they canter at 25 miles per hour (mph), gallop easily at 44 mph, and run flat out at 55
to 62 mph. Sonoran pronghorn does (females) become sexually mature at 16 months, and bucks (males) at
one year. Breeding occurs July through September, gestation is approximately 240 days, and fawning
occurs from February through May coinciding with spring forage abundance. Females typically produce a
single fawn in their first pregnancy and twins thereafter. Fawns appear to suckle for about two months,
thereafter feeding on vegetation. Free-roaming adults appear to live no more than 7 to 9 years (USFWS
1998).
Sonoran pronghorn are opportunistic foragers. Although 132 different plant taxa have been found in their
diet, they prefer plants that are rich in nutritional content and provide moisture, when they are available
(USFWS 1998). Green forbs are highly nutritious, and sought especially by does and fawns in the spring
during late gestation, lactation, weaning, and early fawn growth. Cactus fruits, such as chain fruit cholla,
are often the last nutritional choice in hot, dry seasons. Adult Sonoran pronghorn may survive a
prolonged summer drought on a diet reduced primarily or solely to cactus fruit, but fawns are likely to
perish (USFWS 1998). The current distribution of the Sonoran pronghorn is limited to three
geographically isolated populations—one in the US and two in Mexico (USFWS 2003b). The US
population is limited primarily to the BMGR (west of SR 85), the Refuge, and OPNM west of SR 85 and
south of I-8 (Figure 7). The two Mexican populations are located south of the Refuge and OPCNM and
are geographically isolated from each other into eastern and western groups by Mexican Highway 8. The
US and Mexican populations are isolated from each other by Mexican Highway 2.Typically in the US,
Sonoran pronghorn winter in the valley floors and bajadas, and move south, east, and upslope into
foothills in the summers (USFWS 1998); however, movements are variable depending on environmental
conditions. Slopes greater than 20 percent are generally avoided (Lee et al. 1998). Almost 1,765,000 acres
are encompassed in the current distribution of the U.S. population of which about 1,580,000 acres have
slopes of less than 20 percent. Almost 42 percent of the area in the US occupied by Sonoran pronghorn is
within the BMGR. Another approximately 55 percent of the current pronghorn distribution is under non
military federal land management within the Refuge and OPCNM (USFWS 2003a).
In the late 1800s, Sonoran pronghorn were found over much of southwestern Arizona, northwestern
Mexico, and southeastern California (Figure 8). However, this range was greatly reduced prior to the
establishment of the Refuge. Population decline has been attributed to habitat loss and modification from
23
May 2011
Source: USFWS 2002
Figure 7. Current range of Sonoran pronghorn showing roads and railroads
24
May 2011
Source: USFWS 2002
Figure 8. Current and historic range of Sonoran pronghorn
25
May 2011
livestock grazing, farming, mining, and settlement; habitat fragmentation from roads (especially I-8, SR 85,
and Mexican Highways 2 and 8), fences, railroads, irrigation canals, and large-scale agriculture; hunting
(prior to the 1920s) and some poaching (especially in Mexico); disease introduced by livestock; and
dewatering of the Gila River and the Rio Sonoyta by dams and diversions (USFWS 1998).
Desert tortoise
Desert tortoises that occur east and south of the Colorado River in Arizona are referred to as the Sonoran
population. The Sonoran population was recently determined to warrant protection under the ESA, but is
precluded from listing by higher priorities; the species was added to the list of candidate species for
protection under the ESA (USFWS 2010). Individuals are found throughout their historic range; but
populations are becoming increasingly fragmented due to threats to their habitat in valley bottoms, which
are used for dispersal and exchange of genetic material. These tortoises primarily prefer rocky (often steep)
hillsides and bajadas of Mohave and Sonoran desertscrub, but they may encroach into desert grassland,
juniper woodland, interior chaparral habitats, and even pine communities. Washes and valley bottoms may
be used in dispersal.
3.3 Human Environment
3.3.1 Cultural Resources
Cultural Resource Inventories
Cultural resource inventories are required when new projects will disturb the soil surface, such as road
construction, prescribed fire activities, facilities construction and remodeling, and any other activity that has
the potential to affect historic properties. A cultural resources inventory was conducted by Adrianne
Rankin, BMGR Archaeologist, for the project area (Appendix D). According to the CCP, less than one
percent of the Refuge has been inventoried for archeological and historic sites (USFWS 2006). Available
reports and accounts for the Refuge come from a handful of limited surveys that have been conducted (Ezell
1954, Fontana 1965, Rozen 1979), as well as sporadic visits to the area made by southwest scholars since
the 1920s.
The Cultural Resources Overview and Assessment, Cabeza Prieta National Wildlife Refuge published in
2001 compiles current knowledge of cultural artifacts and use patterns on the Refuge. Within the Refuge,
45 prehistoric and historic sites have been recorded by a statewide survey. In addition, there are numerous
site “leads” and site locations that are known but have not been formally recorded (USFWS 2006).
Prehistoric and Historic Data
Prehistoric sites within the Refuge are generally limited to surface scatters suggesting ephemeral use or
occupation of locations by widely dispersed, small groups of prehistoric hunter-gatherers (USFWS 2006).
Sites observed have included low density artifact scatters, fire-burned rock and hearths, trails, bedrock
mortars, rock alignments, stone piles or cairns, stone windbreaks, sleeping circles, shallow rock shelters,
and petroglyphs (USFWS 2006). Historic sites on the Refuge are primarily early 20th century mining
camps and prospecting strikes (USFWS 2006). El Camino del Diablo is an historic corridor that traversed
parts of the Refuge landscape between 1540 and the late 1800s.
26
May 2011
According to the CCP, ethnographically, the Refuge was the homeland of the Hia C-ed O’odham (Sand
Papago) (USFWS 2006). The Hia C-ed O’odham were Piman-speaking, hunting/gathering populations who
lived west of Ajo throughout historic times. The small, dispersed bands of Hia C-ed O’odham were
encountered by Padre Kino, a late Seventeenth Century Jesuit missionary, who traveled extensively in the
area that became southern Arizona and northern Sonora, and by travelers on El Camino del Diablo for two
centuries. While the archeological evidence does not necessarily correspond to historic linguistic groups, it
suggests that Hia C-ed O’odham ancestry may extend back more than a thousand of years on the Refuge.
3.3.2 Recreation
The Refuge offers visitors a variety of recreation and educational opportunities. A visitor center, located in
Ajo, offers a short interpretive trail and an introduction to the ecology of the Sonoran desert. The Refuge
offers opportunities for hiking, photography, wildlife observation, and primitive camping. Because over 90
percent of the Refuge is designated Wilderness, there are restrictions on certain activities such as use of
motor vehicles, motorized equipment, landing of aircraft, and other forms of mechanical transport. No
vehicle traffic is allowed except on designated public use roads. Because of these restrictions, the character
of sounds on the Refuge is natural, with minimal noise pollution. A recreational user can generally
experience a quiet, natural setting. Visitors to the Refuge are required to obtain a permit, which includes
information regarding authorized activities. Violations of Refuge and Wilderness regulations are enforced
by USFWS. A limited number of desert bighorn sheep hunting permits provide a few hunters a high quality
desert wilderness hunting experience. It must be noted that military and law enforcement activities are
permitted within the Wilderness, so the Refuge is subject to intermittent overflights of military aircraft and
travel of law enforcement vehicles and aircraft.
3.4 Natural Environment
3.4.1 Visual Resources
The Refuge is located near the OPCNM, the BMGR, lands held by the Tohono O’odham Nation, and
Pinacate Biosphere Reserve in Mexico. These areas combine to create a vast area of undeveloped Sonoran
desert with limited evidence of manmade structures. These manmade structures include such elements as
water catchments, water storage tanks, and unpaved roads such as El Camino del Diablo (Devil’s
Highway). The topography of the Refuge consists of broad playas and valleys between long, narrow
mountain ranges such as the Bryan, Granite, Growler, Agua Dulce, and Cabeza Prieta mountains. Views in
the Refuge are generally sweeping vistas across the open desert landscape punctuated with abrupt
landforms such as the Sierra Pintas and Tule Mountains and a numerous rugged peaks such as Sheep
Mountain, Buckhorn Ridge, and Cabeza Prieta Peak. Small desert trees line the ephemeral drainages,
forming braided patterns that radiate from the higher elevations. The wide variety of cactus species
commonly found in the Refuge creates a coarse texture, and the presence of lava flows, sand dunes, and
hoodoos adds to the diversity and scenic value of the landscape (Figure 9).
27
May 2011
Source: Google Earth; hank_snowbirdpix_jorgensen
Figure 9. Existing landscape character in Refuge
3.4.2 Wilderness
In 1974, 833,500 acres of the Refuge were proposed to be included as part of the National Wilderness
Preservation System (Senate Committee on Energy and Natural Resources). The proposal excluded
approximately 37,000 acres along the southern boundary known as the Tule Well exclusion, and a 600-foot
corridor along El Camino del Diablo and the Christmas Pass Road. The proposal included adding the
80,000 acre area known as Tinajas Altas to the Refuge and designating 72,700 acres of the parcel as
Wilderness. Congress directed that the USFWS manage all areas proposed for wilderness as de facto
Wilderness pending study and final designation. A BLM study prior to 1990 indicated that a majority of the
Tinajas Altas area had been impacted by surface military training and no longer possessed high or
threatened cultural, wildlife, scenic or botanical resource values. Tinajas Altas was removed from the 1990
final wilderness proposal due to this degradation. The final proposal included the Tule Well Exclusion, and
narrowed the travel corridors to 200 feet, resulting in a Wilderness proposal of 803,418 acres.
The Arizona Desert Wilderness Act of 1990 (HR 2570 Title 3) designated about 93 percent of the Refuge,
or 803,418 acres as Wilderness. This designation provides an additional Refuge purpose. The Refuge’s
wildlife management responsibilities remain unchanged, but must be implemented within the context of the
Wilderness Act of 1964. While the Wilderness Act does not prevent activities essential to the Refuge’s
purpose, it does affect the manner in which these activities occur. Permanent roads are prohibited in
Wilderness. Temporary roads, use of motor vehicles, motorized equipment, landing of aircraft, other forms
of mechanical transport, and structures and installations are also prohibited, except as minimally required to
administer the area as Wilderness. Additionally, Wilderness designation calls for expanded monitoring
requirements on the effects of public visitation. A MRA is required to make a determination whether the
action under consideration is the minimum necessary for wilderness administration.
28
May 2011
4.0 ENVIRONMENTAL CONSEQUENCES
This chapter analyzes and discusses the potential environmental effects or consequences that can reasonably
be expected with the implementation of the No Action and Proposed Action Alternatives described in
Chapter 2.0 of this EA. An analysis of the effects of management actions has been conducted on the
physical environment (air quality, water quality, and soils); biological environment (vegetation, wildlife,
and threatened and endangered species); the human environment (cultural resources and recreational use);
and the natural environment (visual resources and Wilderness). The direct, indirect, and cumulative impacts
of each alternative are considered. Direct effects are the impacts that would be caused by the alternative at
the same time and place as the action. Indirect effects are impacts that occur later in time or distance from
the Proposed Action Alternative. Cumulative effects are incremental impacts resulting from other past,
present, and reasonably foreseeable future actions, including those taken by federal and non-federal
agencies, as well as undertaken by private individuals. Cumulative impacts may result from singularly
minor but collectively substantial actions taking place over a period of time.
Alternatives for developing (or redeveloping) water catchments for use by Sonoran pronghorn within its
historic range consist of several impact-causing activities. Each of these activities may or may not
potentially affect various aspects of the resource categories. Some resources are most sensitive to
construction and operation of a water catchment system while other resources are more sensitive to the
presence of humans. These effects pathways determine the geographic area of analysis for a specific aspect
of a resource category. For example, special-status plant species would potentially be affected by
construction of the water catchment system, which limits the geographic scope of the analysis to the area of
ground that would be disturbed by each alternative. On the other hand, potential effects to wildlife would
most likely arise from helicopter overflights. Consequently, the geographic area of analysis for that resource
encompasses the entire path that helicopters may take from the staging area to the construction site. The
focus of the affects analysis descriptions for each resource, therefore, is related to the area of analysis for
that resource.
The time frame for the analysis in this EA is up to 10 years from the signing of the final decision and
implementation of the Proposed Action. The construction period of the new water catchments and
improvements to the existing catchments would depend on the availability of funds. The implementation
plan components of the action (emergency use of temporary waters and use of supplemental feed) would
continue indefinitely or until the Sonoran pronghorn have recovered and are delisted.
4.1 Physical Environment
4.1.1 Air Quality
No Action Alternative
The No Action Alternative would maintain the existing air quality conditions in the project area. The use of
helicopters to recharge the existing water catchments would continue and would result in down-draft
generated dust and emissions from the helicopter. If emergency temporary waters are used, additional
helicopter trips would be required (up to once weekly while the temporary waters are in place) resulting in
additional dust generation and emissions. Because the existing catchments are not large enough to allow for
replenishment of water through natural rainfall, recharging would continue each year during periods critical
to the needs of pronghorn. Depending on the duration and timing of non-forage producing periods,
29
May 2011
approximately 15 helicopter flights per season may be undertaken for supplemental feeding.
Implementation of the No Action Alternative would result in minor, long-term, direct, adverse air quality
impacts from water recharging and supplemental feeding activities. No indirect impacts are anticipated.
Proposed Action Alternative
Potential fugitive dust would be created during construction through the digging by with hand tools or by
backhoe. Additionally, helicopter rotor blades create a down-draft of high velocity winds; these down-drafts
could create dust, temporarily impacting the local air quality. Under the Proposed Action it is anticipated
each construction site would require up to 50 helicopter trips to complete a water catchment. Over time, the
number of helicopter trips associated with the Proposed Action would be fewer than the No Action
Alternative. The water catchments would not need to be refilled during the year because they would have a
greater water capacity under the Proposed Action. If emergency temporary waters are used, additional
helicopter trips would be required (up to once weekly while the temporary waters are in place).
Approximately 15 helicopter flights per season may be undertaken for supplemental feeding depending on
the duration and timing of non-forage producing periods. Implementation of the Proposed Action would
result in minor, short- and long-term, direct, adverse air quality impacts. No indirect impacts are
anticipated.
4.1.2 Soils
The No Action Alternative would maintain the existing soil conditions in the project area. The soils at the
site of the existing water catchments may be subjected to increased potential for erosion during periodic
water hauling (estimated to be once per year) and maintenance or repairs of the catchments. In addition, if
temporary waters and supplemental feed are provided, there would be a potential for increased erosion due
to access for water and feed placement. Soil disturbance from small game trails would continue as wildlife
would use the water catchments; this impact would be considered negligible in terms of erosion. Such trails
have been observed naturally occurring near waters in the Refuge. Therefore, the No Action Alternative
would result in minor, long-term, direct, adverse impacts to soil.
Construction activities would increase the potential for erosion within the construction area and along any
access route used by a backhoe until vegetation has re-established. Construction activities would also result
in soil disturbance at the site of the proposed water catchments where desert pavement or cryptogamic soil
crust is present. Desert pavement is present at some proposed catchment locations. Digging by hand or by
backhoe would disturb the surface layer of desert pavement and cryptogamic soil crust during construction;
this impact would be highly localized. The Proposed Action would minimize these disturbances by using
established roadways open to the public for staging and access to the construction areas. After construction
is complete, personnel would return the construction area and the access route to a preconstruction
condition by raking and obscuring tire tracks and footpaths. Wildlife use of the water catchments would
result in establishment of small game trails, which is unlikely to increase erosion of the soils.
30
May 2011
The Proposed Action would result in minor, short- and long-term, direct, adverse impacts to soils from
construction-related disturbance. These impacts would be highly localized and, combined with efforts to
obscure access routes, would fade over time.
4.1.3 Water Resources and Quality
The No Action Alternative would maintain existing water quality and quantity conditions in the project
area. Water quantity available to wildlife at developed water catchments would continue to vary depending
on the time of year, seasonal rainfall, and capacity of the natural and developed water sources found across
the Refuge. Refuge personnel would continue to haul water during the driest times of the year to maintain a
source of water for the pronghorn. The Refuge has averaged about 3,000-gallons a year in the past;
however, occasionally more water has been needed to prevent some systems from going dry. At times water
could not be hauled due to vehicles breaking down, helicopters would not be available on short notice, or
errors would occur in estimating the date the system would run dry. Water is generally obtained from public
water sources in the town of Ajo, Arizona. The 2009 Consumer Confidence Report for municipal water
found no water quality violations and no public notifications during the year. The addition of small amounts
of public water into catchment locations would not affect overall water quality on the Refuge. Therefore,
the No Action Alternative would have no direct or indirect impacts to water quality.
Implementation of the Proposed Action would result in the construction or re-construction of ten water
catchments to a holding capacity of 11,000 gallons of water each. Based on data obtained from field
observations over the last 10 years, Refuge personnel anticipate 11,000 gallons would be sufficient to last
12 to 18 months depending on usage. After construction, the water catchments would be left to fill naturally
from rainfall runoff. Rainfall on the Refuge generally flows within onsite drainages with the majority of the
surface flow rapidly evaporating or infiltrating into the ground. Capturing a small portion of this surface
flow into the 10 catchments would not affect overall water quantity on the Refuge or affect downstream
areas by intercepting water. Therefore, the Proposed Action would have no direct or indirect effect on water
quality and would not require periodic use of domestic water supplies from the Town of Ajo.
4.2 Biological Environment
4.2.1 Vegetation
No direct or indirect impacts to vegetation are expected from continuation of the current management
because no new catchments would be placed.
Water catchment locations are on the bajadas, outside of riparian areas that support dense vegetation.
Disturbance to saguaros, trees, and columnar cactus would be avoided and to the maximum extent possible,
disturbance to native vegetation would be avoided. If cactus cannot be avoided, transplantable specimens
31
May 2011
would be salvaged and transplanted after construction is completed. Therefore, implementation of the
Proposed Action would result in negligible impacts to vegetation during construction. No long-term or
indirect impacts to vegetation are anticipated.
4.2.2 Wildlife
Under the No Action Alternative, the existing habitat conditions would be maintained. There would be no
change in diversity or abundance of wildlife that use the area. Temporary waters and supplemental feeding
may be used on the Refuge during times of prolonged drought in emergency situations for pronghorn. The
temporary waters would be in place for a relatively short duration, either until the emergency conditions
have ended or up to a year according to wilderness regulations. Other wildlife species such as birds, small
mammals and reptiles could also use these temporary waters. Use of the temporary waters would provide
some long-term (short in duration because of the temporary nature of these waters) beneficial impacts to
medium and large mammals.
The No Action Alternative would include the continued use of supplemental feed adjacent to temporary
waters during periods of poor forage production where fawns are present via helicopter to enhance fawn
survival. Depending on the duration non-forage producing periods, helicopter trips to select temporary
water would be needed to move 12 to 24 bales of alfalfa to each of the selected feed sites. The presence of
alfalfa hay at the temporary water sites would provide additional forage to other ungulates, primarily mule
deer and desert bighorn sheep and herbaceous foraging wildlife such as the black tailed jackrabbit that
would be within the immediate vicinity of the feed station. During periods of poor forage production it
would be unusual for mule deer and desert bighorn sheep to occur in such proximity to pronghorn or to
move to temporary feed stations. Supplemental feeding could result in some short-term disturbance to
wildlife in proximity to the feeding stations due to noise created by the helicopter trips as well as having
short-term beneficial impacts because of the presence of the supplemental feed.
Therefore, the No Action Alternative would overall have minor, long-term, direct, beneficial impacts to
wildlife. There would be no indirect or short-term impacts from the No Action Alternative on wildlife.
The proposed permanent waters are located on bajadas at the base of adjacent mountain ranges and
conceivably are available and may be used by desert bighorn sheep and other species of wildlife during the
hot, dry periods. The existing and proposed water troughs are designed as “walk-in” for wildlife and have
escape ramps for small mammals or reptiles that may use or fall in the trough. The long-term benefits to
wildlife by having a permanent source of water outweighs short-term impacts that may occur during
construction activities, such as an increase in human presence, noise, and temporary displacement.
Construction would occur during the winter and spring months. Waters may attract predators; coyotes,
bobcats, and occasional mountain lions have been documented using catchments. However, it is expected
that the benefit to pronghorn would exceed the possible direct mortality associated with predation. No cases
of predation on Sonoran pronghorn at water or forage plots have been documented. The distribution of
predators would not be influenced by the Proposed Action because all predators are already present in the
area. Although man-made waters are thought by some to have expanded the range of mountain lions, this
claim has not been substantiated by research, possibly because of the relative abundance of natural water.
32
May 2011
Emergency water placement may occur during the hot dry season if rains were not sufficient to fill the
holding tanks between rains. Emergency water placement would require additional helicopter over flights
between the designated staging areas the catchments. A biologist would be present on all helicopter flights
and would minimize impacts to wildlife species to the extent possible by avoiding wildlife populations and
taking the most direct flight path.
The Proposed Action includes a supplemental feed program which would be implemented in close
proximity to the waters where fawns are present, as needed during periods of poor forage production to
enhance fawn survival. Depending on the duration and timing of non forage producing periods, helicopters
would be used to initially stock and replenish alfalfa at the selected waters. Alfalfa hay would be available
to wildlife in the feed station in proximity to the catchment and would also be stored off the ground on
pallets and covered with tarps for future use. As discussed in the No Action Alternative alfalfa hay could
provide forage to mule deer, desert bighorn sheep, and herbaceous foraging wildlife such as the black tailed
jackrabbit rabbit. Supplemental feeding via helicopter could result in some short-term disturbance to
wildlife in proximity to the feeding stations due to noise; however, due to the extent of existing aircraft
overflights and the avoidance of wildlife during helicopter flights, the temporary feeding station located
adjacent to temporary waters would have a beneficial impact to some wildlife species.
Therefore, the Proposed Action would overall have minor, long-term, direct, beneficial impacts to wildlife.
There would be no indirect or short-term impacts from the Proposed Action Alternative on wildlife.
4.2.3 Threatened and Endangered Species and Special Status Species
To address potential effects to species listed under the ESA, consultation with the USFWS is required.
Consultation was conducted for two species, Sonoran pronghorn and LLNB, and was initiated by the
submittal of an Intra-Service Biological Assessment Section 7 Biological Evaluation in August 2010. A
Final Biological Opinion will be issued by the USFWS following their review of this Draft EA. The
Biological Opinion will provide specific terms and conditions for implementation to minimize the potential
of incidental take of listed species. These terms and conditions will be binding on the part of the action
agency. Table 5 indicates the potential impacts from the Proposed Action Alternative on the species
protected under the ESA.
Under the No Action Alternative, the existing habitat conditions would be maintained. Existing water
catchments would not be improved and additional waters would not be constructed. Helicopter flights to
recharge waters would conducted during daylight hours when bats are inactive and known bat roosting
areas (such as mine adits) would not be overflown by the helicopter at any point along the routes. No direct
or indirect impacts to LLNB would be anticipated by the No Action Alternative.
Sonoran pronghorn
Under the No Action Alternative, the existing water catchments would not be improved and additional
waters would not be constructed in areas where the pronghorn is known to occur. The long-term
stabilization of the pronghorn population could be substantially impaired as the availability of free water is
33
May 2011
Table 5. Species protected under the Endangered Species Act and the potential impacts from the Proposed
Action Alternative
Common Name
Scientific Name
ESA
Status
Potential for Impacts
from Proposed Action
PLANTS
Acuna cactus
Gooddings onion
Huachuca water umbel
Kearney's blue star
Nichol Turk's head cactus
Pima pineapple cactus
Echinomastus erectocentrus var. acunensis
Allium gooddingii
Lilaeopsis schaffneriana ssp. recurva
Amsonia kearneyana
Echinocactus horizonthalonius var. nicholii
Coryphantha scheeri var. robustispina
C
CA
E
E
E
E
None
None
None
None
None
None
INVERTEBRATES
San Xavier talussnail
Sonorella eremite
CA
None
REPTILES AND AMPHIBIANS
Chiricahua leopard frog
Lithobates [Rana] chiricahuensis
Desert tortoise, Sonoran
Gopherus agassizii
population
Northern Mexican gartersnake
Thamnophis eques megalops
Sonoyta mud turtle
Kinosternon sonoriense longifemorale
Tucson shovel-nosed snake
Chionactis occipitalis klauber
T
C
None
See Analysis
C
C
C
None
None
None
FISH
Desert pupfish
Gila chub
Razorback sucker
Gila topminnow
Cyprinodon macularius
Gila intermedia
Xyrauchen texanus
Poeciliopsis occidentalis occidentalis
E
E
E
E
None
None
None
None
BIRDS
Bald eagle
California least tern
Masked bobwhite
Mountain plover
Mexican spotted owl
Southwestern willow flycatcher
Yellow-billed cuckoo
Yuma clapper rail
Haliaeetus leucocephalus
Sterna antillarum browni
Colinus virginianus ridgewayi
Charadrius montanus
Strix occidentalis lucida
Empidonax traillii extimus
Coccyzus americanus
Rallus longirostris yumanensis
T
E
E
PT
T
E
C
E
None
None
None
None
None
None
None
None
MAMMALS
Jaguar
Ocelot
Sonoran pronghorn
Panthera onca
Leptonycteris curasoae yerbabuenae
Leopardus (=Felis) pardalis
Antilocapra americana sonoriensis
E
E
E
E
None
See Analysis
None
See Analysis
Source: USFWS list of threatened, endangered, proposed, and candidate species occurring in Yuma and Pima Counties, < http://arizonaes.fws.gov/>, accessed September 7, 2010. Status Definitions: ESA = Endangered Species Act, E = Endangered, T = Threatened, PT = Proposed Threatened, C = Candidate, CA = Conservation Agreement Cabeza Prieta National Wildlife Refuge
34
May 2011
vital to sustain the population during periods of drought. Reliance on manual filling of waters by Refuge
personnel can result in waters going dry. Occasionally, water cannot be hauled due to circumstances such as
vehicles breaking down, helicopters not being available on short notice, or human error estimating the date
individual catchments may run dry. These factors have contributed to waters going dry in the past.
Pronghorn may not return to a water development that has gone dry during the summer season. Therefore,
implementation of the No Action Alternative would have moderate, short- and long-term, direct and
indirect adverse impacts to the pronghorn populations on the Refuge.
Sonoran Desert tortoise
Under the No Action Alternative, the existing habitat conditions would be maintained. Existing water
catchments would not be improved and additional waters would not be constructed. No direct or indirect
impacts to Sonoran desert tortoise would be anticipated by the No Action Alternative.
No disturbances to LLNB maternity roosts would occur as a result of the Proposed Action. No mature
columnar cacti or desert agaves, which are used as food plants for LLNB, would be removed. Most
immature cacti and agave would be avoided and if these plants cannot be avoided, they would be salvaged
and replanted on-site. The project would be constructed during the winter months, which is outside of the
typical occurrence of LLNB in southwestern Arizona (May through August). Research has shown that
lactating LLNB use open water sources if they are available, so it is likely that the proposed catchments
would benefit bats. Any flights needed during the warm season months for supplemental feeding would be
done during daylight hours when bats are inactive and known bat roosting areas (such as mine adits) will
not be overflown by the helicopter at any point along the routes. No direct or indirect impacts to the LLNB
are anticipated as a result of the Proposed Action.
Sonoran pronghorn
The Proposed Action would result in disturbance to the Sonoran pronghorn along roads to the staging areas
and along helicopter routes during construction because of an increase in the number of people and
equipment in the vicinity of the water catchments. The minimum number of trips to work sites would be
made to complete construction in the fastest and most efficient manner as authorized in the MRA decision.
Best management practices and conservation measures would be undertaken to avoid or minimize
disturbance to the pronghorns (refer to Section 1.4 Best Management Practices/Conservation Measures).
Placement of temporary waters would provide beneficial impacts to a small population of pronghorn by
providing additional water in times of extreme drought. Fawn mortality would be decreased, resulting in
additional herd recruitment and more rapid recovery toward the population goal outlined in the recovery
plan. Temporary waters would continue to be placed in the vicinity of known herds and would not impact
herds of pronghorn that are not within the immediate vicinity of the waters.
Where supplemental feed is involved, there may be pronghorn lingering near the feed station as the
helicopter makes its initial approach. These pronghorn would be forced away from the site temporarily until
the feed replenishment is completed. Refuge and AGFD staff has documented that Sonoran pronghorn
generally return within several hours to a day following similar disturbance at existing experimental feed
stations (John Hervert, AGFD, personal communication, July 2010). Use of supplemental feed would
35
May 2011
decrease fawn mortality, resulting in additional herd recruitment and more rapid recovery toward the
population goal outlined in the recovery plan.
Therefore the Proposed Action would result in minor, short-term, direct adverse impacts to pronghorn
because of helicopter flights, the presence of humans, and equipment associated with the construction of the
catchments and temporary waters and the hauling of supplemental feed. The Proposed Action would also
result in major, long-term, direct beneficial impacts to Sonoran pronghorn by providing a perennial source
of available water within preferred and occupied habitat in addition to supplemental feeding during periods
of extreme drought. The USFWS has made a preliminary determination of “may affect, likely to adversely
affect Sonoran pronghorn,” and Formal Section 7 consultation will be required. The Proposed Action would
provide long-term, direct beneficial impacts.
Sonoran Desert tortoise
The proposed permanent waters are located on bajadas at the base of adjacent mountain ranges in areas that
could support desert tortoises. Tortoise burrows would not be impacted by construction of the waters as
these tend to be in areas with rock outcrops or wash banks, typically not associated with the bajada. The
existing and proposed water troughs are designed as “walk-in” for wildlife and have escape ramps for
reptiles that may use or fall in the trough. Helicopter flights associated with supplemental feeding or
emergency water hauling would not impact the tortoise. Best management practices and conservation
measures would be undertaken to avoid or minimize disturbance to the tortoise (refer to Section 1.4 Best
Management Practices/Conservation Measures). No direct or indirect impacts to the desert tortoise are
anticipated as a result of the Proposed Action.
4.3 Human Environment
4.3.1 Cultural Resources
No Action and Proposed Action Alternatives
A Class III pedestrian cultural resources survey of the 10 proposed pronghorn waters (new and redeveloped
locations) were conducted to document cultural resources (including prehistoric and historical-period
artifacts and sites, buildings, and structures) (Rankin 2010). The survey was conducted according to the
standards of the Arizona State Museum. No cultural resources were identified at any of the proposed
locations. Therefore, there would be no direct or indirect effects to cultural resources under either the No
Action or Proposed Action Alternatives.
4.3.2 Recreation
The No Action Alternative would slightly alter visitor’s recreational experience within the Refuge over the
long-term; however, these impacts would be intermittent and short in duration. Currently, noise associated
with border patrolling or military activities can be heard within the Refuge. Similar types and levels of
noise would also be heard when emergency water and feed would be provided by helicopter, in addition to
an increase in human activity. These intermittent occurrences of increased noise and human activity would
potentially impact the recreational experience for those present in the Refuge during these emergency
36
May 2011
efforts. Since all recreational users must obtain a permit prior to entering the Refuge, visitors could be
informed about the emergency activities, i.e., presence of helicopters, and where these activities may be
occurring. This would allow the visitor to chose to avoid those areas if they are looking to experience
solitude. Therefore, with the No Action Alternative, there would be negligible impacts to the recreational
experience within the Refuge. The No Action Alternative would have no short-term or indirect impacts to
recreation experience.
The Proposed Action would result in an increase in noise and human activity within the Refuge resulting
from the construction of the proposed and upgrades to the existing water catchments and the construction of
the feed stations. Increased noise would result from the use of vehicles and helicopters to transport workers
and supplies to and from the construction sites, as well as at the construction sites due to the use of
equipment. Construction impacts would be temporary in nature and cease when construction is complete.
The impacts associated with noise generated by vehicles and helicopters would incorporate the travel routes
of each, while the extent of the construction would be localized to the catchment and feeding locations. The
placement of feed in the feeders would result in temporary generations of noise while the feed is transported
by helicopter to the temporary feeding sites. These increased noise levels and human activity would be
intermittent and short in duration, but occur over the long-term. Information on where these activities are to
occur could be provided to the recreational users when they obtain their permit for the Refuge. By
providing this information to visitors that would provide them the opportunity to avoid construction areas,
the long-term impact on recreation experience from the Proposed Action Alternative would be negligible.
The Proposed Action would have a minor, short-term, direct, adverse impact on recreation experience
during the construction of the proposed and upgrades to the existing water catchments; there would be no
indirect or long-term impacts to recreation experience.
4.4 Natural Environment
Under the No Action Alternative, the existing water catchments would be maintained. During water hauling
activities from the dust created by the helicopter, it is anticipated that there would be changes to the visual
character of the landscape, but these direct impacts would be of short duration. If temporary waters were
placed or supplemental feed used, there would be the construction of temporary catchment consisting of a
small holding tank (up to 2,000 gallons) and a 100 to 150-gallon drinking trough. The holding tanks would
be draped with camouflage netting and the netting secured to the ground either by rebar staking or by using
large rocks as anchors. The drinking trough would be partially buried in the ground to secure the tank,
which would limit its visibility from a distance. Supplemental feed stations would be constructed out of
lumber and would be approximately 2 feet high. It is anticipated that the temporary waters or feeding stands
would not attract the attention of the typical visitor to the Refuge when viewed from more than 0.25 mile
from the site. Therefore, there would be minor, short- and long-term, direct adverse impact on visual
resources under the No Action Alternative because of the dust created by on-going water hauling activities
to the existing water catchments and soil and vegetation disturbance from the construction of temporary
waters and supplemental feeding stations. No indirect impacts on visual resources are anticipated from the
No Action Alternative.
37
May 2011
Changes in the existing landscape character would occur from the presence of construction equipment,
creation of dust, and an increase in the presence of humans during construction of the five new catchments
and enlarging five of the existing catchments. The only above-ground features of the water catchments
would be the at-grade diversion structure and water trough. Water storage and conveyance pipes would be
placed below ground. The diversion structure would be camouflaged by the placement of rocks around the
openings. Direct impacts to visual resources associated with the Proposed Action would occur from the soil
and vegetation disturbance that would be apparent at each new and existing water catchment site during and
after construction/renovation activities. Airborne dust would be visible during construction activities due to
the increased use of helicopters and equipment in the area. This would be temporary and would cease once
construction activities are complete. Design features of the enlarged water catchments would help the above
ground features blend in with the natural surroundings, and would not attract the attention of the typical
visitor to the Refuge when viewed from more than 0.25 mile from the site. In addition with the enlarged
water catchment components, fewer water hauling trips, if any, would be required than previously needed
for the existing catchment. If temporary waters were placed or supplemental feed used, there would be
direct impacts to visual resources, similar to the No Action Alternative. These impacts would diminish over
time as vegetation reclaimed the sites. The Proposed Action, therefore, have minor, short- and long-term,
direct adverse impacts to visual resources. No indirect impacts to visual resources from the Proposed Action
were identified.
4.4.2 Wilderness
Actions required to complete the proposed action will take place within the Cabeza Prieta Wilderness area.
Wilderness values were evaluated using criteria that relate to qualities of Wilderness character including
untrammeled (not subject to human manipulation that hamper the flow of natural forces), undeveloped,
natural, and outstanding opportunities for solitude or a primitive and unconfined type of recreation. In
addition, the preservation of Sonoran pronghorn, which is a unique component of this Refuge, was
considered a Wilderness value. No heritage or cultural resources would be impacted by the No Action
Alternative or Proposed Action Alternative. A MRA is being completed by the USFWS to evaluate and
determine minimum resources required to implement the proposed action in accordance with Section 4(c)
of the Wilderness Act of 1964. The MRDG will be completed to identify, analyze and select management
actions that are the minimum necessary for wilderness and is an evaluation of all available options, within
agency safety requirements, needed to make an appropriate decision for wilderness.
Under the No Action Alternative, the existing conditions would be maintained at the existing catchments
and there would be no change to existing wilderness values over the existing. However, if temporary waters
or emergency feed are placed within designated Wilderness on the Refuge, these actions would have direct
impacts to Wilderness values. Placement of the waters and feed would require use of helicopters and
equipment for construction of the temporary waters and feeding stations. Refilling of the catchments and
maintenance and refilling feed holders would require return helicopter trips resulting in impacts to
Wilderness character and experience. The presence of the personnel and helicopters could interfere with the
sense of solitude for any recreational user and the untrammeled and undeveloped character of the area,
resulting in minor, short- and long-term, direct adverse impacts to the Wilderness experience and character.
The No Action Alternative would also have a moderate, long-term, direct, beneficial impact to Wilderness
38
May 2011
values in relationship to Sonoran pronghorn. No indirect impacts to Wilderness values, experience, or
character are anticipated.
An MRA is being prepared to evaluation the Proposed Action and other MRA alternatives. The presence of
the work crew, construction noise, and helicopters could interfere with the sense of solitude for any
recreational user in the area during the construction of the five new water catchments and the enlargement
of the five existing catchments. This effect would be temporary, but the construction of the water
catchments would take approximately 274 days. The area surrounding the water catchment, camping area,
and route into the site from the nearest designated road would be manipulated during the work period. Per
the Conservation Measures incorporated into the Proposed Action Alternative, efforts would be made to
return the area to preconstruction conditions and to camouflage the route to prevent unauthorized vehicle
access. A camping area would be used at each construction site for two to three nights. The area
surrounding the catchment, camping area, and route to the site from the nearest designated road would
become altered during the construction period. Once constructed, inspections of the catchment would be
made on foot. There is no planned future vehicle access to the water catchment, which would allow
disturbed areas to naturally re-vegetate to a similar condition as surrounding lands, disturbed areas during
construction would become unremarkable on the landscape. The provision of feed to the pronghorn would
affect the untrammeled nature of the area surrounding the feeder. However, camping would not be required
shortening the duration of any given occurrence, but these occurrences would be ongoing for as long as feed
as provided.
The only above-ground features of the water catchments are the at-grade diversion structure and water
trough. Water storage and conveyance pipes are placed below ground. The diversion structure is
camouflaged by the placement of rocks around the openings. Supplemental feed stations are constructed out
of lumber to keep the feed off of the ground. The above-ground features would only be visible to a person
that is in close proximity to the catchment or feeding stand. It is unlikely that the catchment or feeding stand
would attract attention from the casual Refuge visitor if they are more than 0.25 mile away from the site.
The Proposed Action would have impacts to Wilderness character including temporary disturbance at the
catchment locations including the camping area and access routes; generation of dust; and temporary
presence of construction crews. These impacts would be temporary and restricted to construction activities.
The Proposed Action also would introduce permanent features into the Wilderness that are not natural
features consisting of the catchments and feeders; however, the physical and visual impact of the structures
would be minimized through the design features and Conservation Measures incorporated into the Proposed
Action to minimize the overall impact of their presence. These features would be constructed using
traditional skills to the extent feasible (four of the 10 locations). The Proposed Action would have a major,
long-term, direct, beneficial impact to Wilderness values in relationship to Sonoran pronghorn and a minor,
short- and long-term, direct, adverse impact to Wilderness character. No indirect impacts to Wilderness
values, experience, or character are anticipated.
4.5 Assessment of Cumulative Impacts
A cumulative impact is defined as an impact on the environment that results from the incremental impact of
the proposed action when added to other past, present, and reasonably foreseeable future action regardless
of what agency (federal or nonfederal) or person undertakes such other actions. Cumulative impacts can
39
May 2011
result from individually minor but collectively significant actions taking place over a period of time
(40 CFR 1508.7).
Cumulative impacts are the overall, net effects on a resource that arise from multiple actions. Impacts can
“accumulate” spatially, when different actions affect different areas of the same resource. They can also
accumulate over the course of time, from actions in the past, the present, and the future. Occasionally,
different actions counterbalance one another, partially cancelling out each other’s effects on a resource. But
more typically, multiple effects add up, with each additional action contributing an incremental impact on
the resource. For purposes of this analysis, past, ongoing and reasonably foreseeable future actions that
occur on the Refuge were considered.
Refuge staff identified the following past, ongoing, and reasonably foreseeable future activities that may
occur on the Refuge:

Border-Related Activities
o
o
o
o
SBI Net (existing network of towers within OPCNM).
Illegal border crossers and Border Patrol activities (patrol and intercept of illegal border
crossers) on the Refuge.
Periodic radio repeater maintenance: 6 repeaters total, five are within wilderness. One
involves new construction.
Proposed road improvements along the El Camino del Diablo (perhaps widening).

Maintenance and construction of waters for bighorn sheep.

Periodic water hauling for Sonoran pronghorn and bighorn sheep.

Ongoing military operations including military aircraft flights over the Refuge.

Introduction and overflights of the new F-35 Joint Strike Fighter.
For the purpose of this EA, the cumulative effects analysis focuses on the incremental effect of the No
Action and Proposed Action Alternative when added to other past, present, and reasonably foreseeable
future actions. The cumulative effects analysis area includes the current range of Sonoran pronghorn within
the US (see Figure 7). Environmental resources that have minor, moderate, or major, long-term direct
impacts by the No Action or Proposed Action Alternatives are discussed. The effects on each environmental
resource are described as having a beneficial, adverse, or no impact on a given resource. The magnitude or
degree of impact is classified as negligible, minor, moderate, or major. All impacts discussed are considered
long-term.
4.5.1 Air quality
The No Action Alternative would result in creation of fugitive dust and vehicle/helicopter emissions during
the construction and maintenance of temporary waters and supplemental feeding stations. Other ongoing
and reasonably foreseeable projects such as border control activities and bighorn sheep water catchment
projects would result in similar impacts to air quality that are of short duration and localized. Therefore, the
No Action Alternative would contribute incrementally to a minor adverse cumulative impact to air quality
40
May 2011
when considered along with past, present, and reasonably foreseeable future actions in the geographic area
of influence.
The Proposed Action would result in creation of fugitive dust and vehicle/helicopter emissions during the
construction and maintenance of temporary waters and supplemental feeding stations. These impacts would
be localized, of short duration, and occur only in extreme drought conditions. Other ongoing and reasonably
foreseeable projects such as border control activities and bighorn sheep water catchment projects would
result in more frequent, localized impacts of short duration to air quality. Therefore, when considered along
with past, present, and reasonably foreseeable future actions in the geographic area of influence, the
Proposed Action would have a negligible contribution to cumulative impacts to air quality.
4.5.2 Soils
Similar to both the No Action and Proposed Action Alternatives, other Refuge wildlife management
activities would have minor direct impacts on soils from the potential increase in erosion. Border Control
activities and illegal border crossers create soil impacts from the foot trails and vehicles patrolling the
Refuge and intercepting illegal border crossers. Border activities have impacts that are more wide-spread,
though more concentrated on the southern portion of the Refuge near the US-Mexico border. Therefore,
when considered along with past, present, and reasonably foreseeable future actions in the geographic area
of influence, the No Action and Proposed Action Alternatives would have a negligible contribution to
cumulative soil impacts.
4.5.3 Wildlife
The No Action and Proposed Action Alternatives would provide long-term beneficial impacts to wildlife
species from the placement of permanent sources of perennial water. Other Refuge wildlife management
activities would have similar beneficial impacts, such as placement of waters for bighorn sheep. Borderrelated activities such as illegal border crossing and enforcement activities have adverse impacts on general
wildlife related to presence of humans and vehicles that harass wildlife, create footpaths and roads, and
deposit litter that can be harmful to wildlife. When considered along with past, present, and reasonably
foreseeable future actions in the geographic area of influence, both alternatives would have a negligible
contribution to cumulative impacts to wildlife species related to human presence in wildlife habitat and both
would have a minor beneficial cumulative impact to wildlife species related to placement of permanent
sources of water.
4.5.4 Threatened and Endangered Species and Special Status Species (Sonoran pronghorn)
The No Action Alternative would result long-term moderate beneficial impacts to Sonoran pronghorn on
the Refuge and reduction of fawn mortality. Border-related activities such as illegal border crossing and
41
May 2011
enforcement activities have adverse impacts on Sonoran pronghorn related to presence of humans and
vehicles that harass pronghorn and create footpaths and roads. When considered along with past, present,
and reasonably foreseeable future actions in the geographic area of influence, the No Action Alternative
would contribute to a minor beneficial cumulative impact to Sonoran pronghorn.
The Proposed Action would result long-term major beneficial impacts to Sonoran pronghorn related to
placement of perennial sources of water within preferred and occupied habitat on the Refuge and reduction
of fawn mortality. Border-related activities such as illegal border crossing and enforcement activities have
adverse impacts on Sonoran pronghorn related to presence of humans and vehicles that harass pronghorn
and create footpaths and roads. When considered along with past, present, and reasonably foreseeable future
actions in the geographic area of influence, the Proposed Action would contribute to a moderate beneficial
cumulative impact to Sonoran pronghorn and would help reduce the overall adverse cumulative impact to
Sonoran pronghorn in the long term.
The No Action and Proposed Action Alternatives would result in direct adverse impacts to existing visual
resources. These impacts would be localized impacts and the visibility of the catchments, temporary waters,
and feeding stations would be reduced when viewed from more than 0.25 mile away. Other Refuge wildlife
management activities, border control activities such as vehicles patrolling the Refuge, and illegal border
crossers that create foot trails results in the introduction of structures, elements, and patterns that detract
attention away from the natural setting. Other Border-related activities on the Refuge may require
placement of permanent structures or roads such as radio-repeaters or border towers that would lower the
scenic integrity of the landscape. Therefore, when considered along with past, present, and reasonably
foreseeable future actions in the geographic area of influence, the No Action and Proposed Action
Alternatives would incrementally contribute to a minor adverse cumulative impact to visual resource when
considered along with past, present, and reasonably foreseeable future actions in the geographic area of
influence.
4.5.6 Wilderness Values
The No Action Alternative would introduce temporary waters and feeding stations features into the
Wilderness that are not natural features and would impact the Wilderness character during extreme drought
conditions. Other Refuge wildlife management activities, border control activities, and illegal border
crossers that create foot trails results in the introduction of structures, elements, and patterns that also
impact the Wilderness character. Other Border-related activities on the Refuge may require placement of
permanent structures or roads such as radio-repeaters or border towers that would lower the scenic integrity
of the landscape. The Proposed Action would have a moderate direct beneficial impact to Wilderness values
related to Sonoran pronghorn, which is a unique component of this Refuge. When considered along with
past, present, and reasonably foreseeable future actions in the geographic area of influence, the Proposed
Action would contribute to negligible cumulative impacts related to placement of structures within a
42
May 2011
Wilderness that are not natural features, but would contribute to minor beneficial cumulative impacts to
Wilderness value related to Sonoran pronghorn, a unique component of this Refuge.
The Proposed Action would introduce permanent features into the Wilderness that are not natural features
and would impact the Wilderness character. Other Refuge wildlife management activities, border control
activities such as vehicles patrolling the Refuge, and illegal border crossers that create foot trails results in
the introduction of structures, elements, and patterns that also impact the Wilderness character. Other
Border-related activities on the Refuge may require placement of permanent structures or roads such as
radio-repeaters or border towers that would lower the scenic integrity of the landscape. All management
actions proposed to occur within designated wilderness on the refuge are subject to MRA to verify the
action is necessary to administer the area as Wilderness and verify that the action is the minimum required
to meet the need for management intervention in Wilderness. The Proposed Action would have a major
direct beneficial impact to Wilderness values related to Sonoran pronghorn, which is a unique component of
this Refuge. When considered along with past, present, and reasonably foreseeable future actions in the
geographic area of influence, the Proposed Action would contribute to minor adverse cumulative impacts
related to placement of structures within a Wilderness that are not natural features, but would contribute to
moderate beneficial cumulative impacts to Wilderness value related to Sonoran pronghorn, a unique
component of this Refuge.
4.6 Indian Trust Assets
No Indian Trust Assets have been identified in the Refuge. There are no reservations or ceded lands present.
Because resources are not believed to be present, no impacts are anticipated to result from implementation
of either alternative described in the EA.
4.7 Unavoidable Adverse Effects
No unavoidable adverse impacts are anticipated by implementation of the Proposed Action.
4.8 Irreversible and Irretrievable Commitment of Resources
Irreversible and irretrievable resource commitments are related to the use of nonrenewable resources and
the effects that this use could have on future generations. Irreversible effects primarily result from the use or
destruction of specific resources that cannot be replaced within a reasonable time frame, such as energy or
minerals. Irretrievable resource commitments involve the loss in value of an affected resource that cannot
be restored as a result of the action, such as extinction of a threatened or endangered species or the
disturbance of a cultural resource.
None of the alternatives would result in a large commitment of nonrenewable resources. Project
implementation would require the irretrievable commitment of fossil fuels (diesel and gasoline), oils, and
lubricants used by heavy equipment and vehicles. The No Action and Proposed Action Alternatives may
result in unavoidable harm or harassment to some wildlife. The USFWS would implement best
management practices to minimize potential impacts as outlined in the description of the Proposed Action.
Although some nonrenewable resources would be used to implement the Proposed Action, when compared
43
May 2011
to the No Action Alternative, the Proposed Action would reduce the use of fossil fuels needed for water
hauling and maintenance activities.
4.9 Summary of Potential Environmental Effects
Table 6 provides a summary of the potential environmental effects of the No Action and Proposed Action
Alternatives.
Table 6. Summary of environmental effects by alternative
Environmental
Resource
Air Quality
Minor, long-term, direct adverse air quality
impacts if temporary waters or forage are
placed. No indirect impacts are anticipated.
Minor adverse cumulative impact.
Minor, short- and long- term, direct, adverse air quality impacts. No indirect impacts are anticipated. Negligible contribution to
cumulative impacts on air quality.
Soils Direct minor, long-term adverse impacts water
hauling and maintenance or repairs of the
existing water catchments. Negligible
contribution to cumulative impacts on air
quality.
Minor, short- and long-term, direct, adverse
impacts to soils from construction-related disturbance. These impacts would be highly
localized and combined with efforts to obscure access routes, would fade over time. Negligible contribution to cumulative impacts on air quality. Water Resource and
Quality
No direct, indirect, or cumulative impacts to
water quality or quantity.
No direct or indirect effect to water quality and would not require periodic use of domestic water supplies from the Town of Ajo. No
cumulative impacts to water quality or quantity.
Vegetation No direct, indirect, or cumulative impacts to
vegetation.
Negligible impacts to vegetation during
construction. No long-term, indirect, or
cumulative impacts to vegetation are anticipated. Wildlife
Minor, long-term, direct, beneficial impacts to
wildlife. There would be no indirect or shortterm impacts on wildlife. Minor beneficial
cumulative impact.
Minor, long-term, direct, beneficial impact to wildlife. No short-term or indirect impacts anticipated. Moderate beneficial cumulative impact. Threatened and
Endangered Species
LLNB: No direct or indirect impacts.
Sonoran pronghorn: Moderate, short-and longterm, direct and indirect adverse impacts to the
pronghorn populations on the Refuge. Minor
beneficial cumulative impact.
LLNB: No direct or indirect impacts.
Sonoran pronghorn: Minor, short-term, direct, adverse impacts during construction and major,
long-term, direct, beneficial impacts upon completion of water catchments and providing temporary waters and supplemental feeding. Moderate beneficial cumulative impact. Sonoran Desert tortoise: No direct or indirect
impacts. Cultural Resources
No direct, indirect, or cumulative impacts.
No direct, indirect, or cumulative impacts. Cabeza Prieta National Wildlife Refuge
44
May 2011
Table 6. Summary of environmental effects by alternative
Environmental
Resource
Recreation Negligible direct impacts. No short-term,
indirect, or cumulative impacts anticipated.
(Continued)
Direct, minor, short-term adverse impact during
construction. No indirect, long-term, or
cumulative impacts.
Visual Resources Minor, short- and long-term, direct adverse
impact on visual resources due to the placement
of temporary waters and feed. No short-term or
indirect impacts are anticipated. Minor adverse
cumulative impact.
Minor, short- and long-term, direct, adverse
impacts on visual resources from the
construction of catchments and feeding stations.
No indirect impacts are anticipated. Minor
adverse cumulative impact.
Wilderness Moderate, long-term, direct, beneficial impact
to Wilderness values in relationship to Sonoran
pronghorn. Minor, short- and long-term, direct
adverse impacts to the Wilderness experience
and character. No indirect impacts to
Wilderness value, experience, or character are
anticipated. Negligible cumulative impacts on
Wilderness character; minor beneficial
cumulative impacts to Wilderness value.
Major, long-term, direct, beneficial impact to
Wilderness values in relationship to Sonoran
pronghorn. Minor, short- and long-term, direct,
adverse impact to Wilderness character. No
indirect impacts to Wilderness values,
experience, or character are anticipated. Minor
adverse cumulative impacts on Wilderness
character; moderate beneficial cumulative
impacts to Wilderness value.
45
May 2011
5.0 CONSULTATION, COORDINATION AND DOCUMENT
PREPARATION
Document prepared by Refuge Staff, Cabeza Prieta National Wildlife Refuge, USFWS, Ajo, Arizona.
Agencies and individuals consulted in the preparation of this document include:






John Hervert, AGFD Jill Bright, AGFD James Atkinson, USFWS
Curt McCasland, USFWS Sid Slone, USFWS Tim Tibbitts, NPS Cabeza Prieta National Wildlife Refuge
46
May 2011
6.0 REFERENCES
AFGD. 2003. Leptonycteris curasoae yerbabuenae. Unpublished abstract compiled and edited by the
Heritage Data Management System, AGFD. Phoenix, AZ.
Beale, D.M., and R.C. Holmgren. 1975. Water requirements for antelope fawn survival and growth. Utah
Department of Natural Resources Wildlife federal Aid Project W-65-D-23. Salt Lake City, UT.
Bright, J.L., and J.J. Hervert. 2005. Adult and fawn mortality of Sonoran pronghorn. Wildlife Society
Bulletin.
Brown, D.E. and R.A. Ockenfels. 2007. Arizona’s pronghorn antelope: A conservation legacy. Arizona
Antelope Foundation, Phoenix, Arizona, U.S.
Brown, D. E. and R. A. Ockenfels. 2007. Arizona’s Pronghorn Antelope, A Conservation Legacy. Arizona
Antelope Foundation.
Cockrum, E. L., and Y. Petryszyn. 1991. The long-nosed bat, Leptonycteris: an endangered species in the
southwest? Occasional Papers, The Museum, Texas Tech University. Lubbock, TX.
Ezell, Paul. 1954. An Archeological Survey of Northwestern Papgueria. Kiva: The Journal of Southwestern
Anthropology and History.
Fontana, B.L. 1965. An Archeological Site Survey of the Cabeza Prieta Game Range, Arizona. Manuscript
on file, Arizona State Museum Library. Tucson, AZ.
Fox, Lisa, M. 1997. Nutritional content of forage in Sonoran pronghorn habitat, Arizona. Thesis, University
of Arizona. Tucson, AZ.
Fox, L.M., P.R. Krausman, M.L. Morrison, and R.M. Kattnig. 2000. Water and nutrient content of forage in
Sonoran pronghorn habitat, Arizona. California Fish and Game.
Hall, T.E. 2001. “Hikers’ perspectives on solitude and wilderness.” International Journal of Wilderness.
Hayward, B. J. and E. L. Cockrum. 1971. The natural history of the western long-nosed bat, Leptonycteris
sanborni. Western New Mexico University Research in Science. Silver City, NM.
Hervert, J.J., J.L. Bright, M.T. Brown, L.A. Piest, and R.S. Henry. 2000. Sonoran pronghorn population
monitoring: 1994 – 1998. Nongame and endangered wildlife program technical report 162. AGFD.
Phoenix, AZ.
Hoffmeister, D. F. 1986. Mammals of Arizona. The University of Arizona Press and AGFD.
Hosack, D.A., P.S. Miller, J.J. Hervert, and R.C. Lacy. 2002. A population viability analysis for the
endangered Sonoran pronghorn, Antilocapra Americana sonoriensis. Mammalia: International
Journal of the Systematics, Biology and Ecology of Mammals.
Lee, R. M., J. D. Yoakum, B. W. O’Gara, T. M. Pojar, and R. Ockenfels, eds. 1998. Pronghorn
management guides. Eighteenth Pronghorn Antelope Workshop. Prescott, Arizona.
47
May 2011
Morgart, J.R., J.J. Hervert, P.R. Krausman, J.L. Bright, and R.S. Henry. 2005. Sonoran pronghorn use of
anthropogenic and natural water sources. Wildlife Society Bulletin.
O’Gara, B.W., and J.D. Yoakum, editors. 1992. Pronghorn management guides. Pronghorn antelope
workshop. Rock Springs, WY.
Rankin, Adrianne G. 2010. Intensive Archeological Survey of Ten Water Catchments on the Cabeza Prieta
National Wildlife Refuge, Southwestern AZ. Oct 3 2010. 56 RMO/ESM Luke AFB, AZ
Rozen, Kenneth. 1979. The Cabeza Prieta Game Range Fenceline Survey. Arizona State
MuseumArcheological Series. University of Arizona. Tucson, AZ.
Schmidt-Nielson, Knut. 1964. Desert Animals: Physiological Problems of Heat and Water. Oxford
University Press, London, UK.
Spicer, B. 1988. Nongame Field Notes. AGFD. Phoenix, AZ.
Turner, R. M. and D. E. Brown. 1994. “Sonoran Desertscrub” in Biotic Communities: Southeastern United
States and Northwestern Mexico, edited by D. E. Brown. University of Utah Press. Salt Lake City,
UT.
USFWS. 1998. Final revised Sonoran pronghorn recovery plan. USFWS. Albuquerque, NM.
USFWS. 2002. Recovery Criteria and Estimates of time for Recovery Actions for the Sonoran Pronghorn:
A Supplement and Amendment to the Final Revised Sonoran Pronghorn Recovery Plan. January
2002.
USFWS. 2003a. Biological and conference opinion for the Organ Pipe Cactus National Monument General
Management Plan, consultation no. 02-21-89-F-078R1, April 7, 2003. USFWS, Arizona Ecological
Services Field Office. Phoenix, AZ.
USFWS. 2003b. Supplement and Amendment to the 1998 Final Revised Sonoran Pronghorn Recovery Plan
(Antilocapra americana sonoriensis). Albuquerque, NM.
USFWS. 2006. Cabeza Prieta National Wildlife Refuge Comprehensive Conservation Plan, Wilderness
Stewardship Plan and Environmental Impact Statement. Albuquerque, NM.
USFWS 2010. Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition to List the
Sonoran Population of the Desert Tortoise as Endangered or Threatened; Proposed Rule. Federal
Register Vol. 75, No. 239 / Tuesday, December 14, 2010. 53pp.
Yoakum, J.D. 1994. Water requirements for pronghorn. Proceedings of the Pronghorn Antelope Workshop
Proceedings.
48
May 2011
Appendix A AGFD Guidelines for Handling Sonoran Desert Tortoises
Appendix B Comment Letter Appendix C Biological Evaluation
Appendix D Intensive Archaeological Survey of Ten Water Catchments on the Cabeza Prieta National Wildlife Refuge, Southwestern AZ

Draft Environmental Assessment Cabeza Prieta National Wildlife

Transcription

Similar documents

Sonoran Pronghorn Recovery Update

New Bills Threaten National Parks, Wilderness, Wildlife Refuges

jake johnson - Ogallala Commons

awl-nyt - Protect The Arctic Refuge

TCWR 2015 Brochure

Echo : Voice of the Blue Mountain

View

99.333 acres - Henry S. Miller

NWRA, Friends of Chassahowitzka National Wildlife Refuge

Vehicle Trails Associated with Illegal Border Activities on Cabeza