HWW Folder Outside - Healthy Waterways

Transcription

SUPPORTED
QMBA
Queensland Master
Builders Association
417 Wickham Terrace
Brisbane QLD 4000
Ph: (07) 3404 6444
Fax: (07) 3832 2361
www.masterbuilders.asn.au
BY
HIA
Housing Industry
Association Ltd
PO Box 3573
South Brisbane QLD 4101
Ph: (07) 3846 1298
Fax: (07) 3846 3794
www.hia.com.au
Copyright 2006
These guidelines are protected by Australian copyright law.
For permission to use any of the material, contact the
Brisbane City Council or Gold Coast City Council. Some photographs
and drawings are owned by Catchments & Creeks Pty Ltd.
Sediment from building sites is choking our local
creeks, rivers and marine systems. It is vital that erosion
and sediment controls are in place on building sites to
reduce the amount of sediment and other pollutants
entering the waterways.
www.healthywaterways.org
All of us – homeowners, government and the building
industry – have a role to play in protecting our waterways.
Play your part – check and maintain controls daily.
Moreton Bay
Controlling stormwater pollution
on your building site
Controlling stormwater pollution on your building site
Contents
Introduction
What are the impacts?. . . . . . . . . . . . . . . . . . . . . . . . . . 2
These guidelines provide a practical guide to best
practice techniques to minimise stormwater pollution from
building sites. They are designed to help people involved
in the building industry comply with their statutory
environmental duties and avoid large fines.
Erosion and sediment control on
residential building sites . . . . . . . . . . . . . . . . . . . . . . . . 2
Environmental law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Erosion controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Sediment control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
The following fact sheets provide practical examples
of recommended control measures. Included is an easyto-follow daily site checklist to guide site supervisors.
Drainage control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1
Erosion and sediment control daily site check list
2
Erosion and sediment control on residential
building sites
3
Erosion control
4
Sediment control
5
Drainage control
6
Building operations
7
Storage of materials on hard surfaces
8
Grouped building lots
9
Erosion and Sediment Control Management Plans
Building operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Storage of materials on hard surfaces. . . . . . . . . . . . . . 8
Grouped building lots . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Erosion and Sediment Control Management Plans . . . 9
Erosion and sediment control
daily site check list
An erosion and sediment control check list has been
developed to assist builders and site supervisors
managing the task of control measure maintenance.
For further information on erosion and sediment control,
contact your local council.
LEGEND
✓
– Best practice
✕
– Not best
practice
BEST PRACTICE
Best practice is the management of an activity to ensure
environmental harm is minimised using cost-effective
measures. These practices are assessed against national
and international standards.
SAVE MONEY TIME AND ENERGY
Some of the benefits to home owners, builders and
the building industry include:
•
•
•
•
•
•
•
•
•
•
•
•
all-weather site access
improved wet weather working conditions
sites do not get boggy
less mud and dust problems
reduced stockpile losses
reduced clean-up costs
a better public image
more marketable sites
fewer public complaints
reduced risk of fines
better fishing for everyone
healthier waterways.
National and international experience shows that the
cost of effective pollution management on building sites
is greatly reduced within the first few years as builders
become experienced with the various techniques.
1
What are the impacts?
SEE FACT SHEET 2
Soil, sediment and litter from building sites can be major
sources of stormwater pollution, and can cause:
•
negative impacts on recreational fishing and
the seafood industry
•
sediment build-up within waterways which
can lead to weed growth
•
loss of valuable topsoil
•
significant public safety problems when washed
onto roads and intersections
•
blocked drains and water sensitive urban design
features leading to flooding and increased
maintenance costs to the community
•
significant harm to the environment of freshwater
and marine systems through the loss of valuable
seagrass habitat for marine creatures
•
public health issues from increased algal blooms
•
reduced recreational opportunities due to increased
turbidity
✕
Mud and dirt on road after rain due to poor
on-site erosion and sediment control
✕
Sediment moving out of Moreton Bay into the ocean
through Jumpinpin
Erosion and sediment control on residential building sites
SEE FACT SHEET 2
Principles of effective stormwater pollution control include:
•
sensible site planning
•
diversion of up-slope water (where appropriate)
•
stabilised site entry/exit point
•
minimisation of site disturbance and duration of
disturbance
•
installation of sediment controls along the lower
edge of the site
•
appropriate location and protection of stockpiles
•
early connection of roofwater downpipes
•
trap on-site run-off from tool, paint and concrete
washing and brick, tile and concrete cutting
•
continual monitoring and maintenance of all
control measures
•
compaction of backfilled trenches
•
revegetation and stabilisation of the site
•
development and implementation of Erosion
and Sediment Control Management Plans
when appropriate.
✓
Control measures in place on a residential building site
2
SITE PLANNING
When planning the site layout, building location and earthworks, it is possible to minimise the number
of control devices needed for the sediment control zone, and their interference with the building process,
with a little forward thinking. Suggestions are to:
•
minimise the reshaping of the land
•
direct stormwater to flow around the building area and any unstable batters
•
allow room for a sediment barrier, eg. sediment fence, to be located along the lower side of the disturbance
•
design the home to suit the property type, eg. construct pole homes on steep properties
•
avoid the permanent use of long, steep and unstable driveways
•
avoid the use of exposed aggregate concrete surfaces in areas where the wash-off cannot be contained.
Sediment Control Zone
✓
Good site planning
Environmental law
✕
The sediment control zone is any
area of land disturbance which has
potential for the erosion of sediments.
This area should be protected by a
downslope sediment control
measure or device.
Poor site planning – stockpile over
sediment fence, materials and toilet
stored outside building site
SEE FACT SHEET 2
The Environmental Protection Act 1994, Environmental Protection (Water) Policy 1997 and the Integrated Planning
Act 1997 are important pieces of legislation that control the way in which soil erosion and sediment are required to
be dealt with on building and development sites.
PENALTIES
Breaches of the Environmental Protection (Water) Policy
1997 may result in:
•
on-the-spot fines under the Environmental Protection
(Water) Policy 1997 (ranging from $300 to $600)
•
prosecutions under the Integrated Planning Act
1997 or the Environmental Protection Act 1994
(fines of thousands of dollars or prison sentences
for serious offences)
•
the prosecution of individuals and/or companies.
3
Council officer explaining the Environmental Protection
(Water) Policy 1997
Erosion controls
SEE FACT SHEET 3
MINIMISE DISTURBANCE
•
Earthworks should be kept to a minimum, and should only be commenced immediately prior to building works.
•
Maintain as much soil coverage as possible with the use of grass, leaf litter and mulch, gravel or erosion control
blanket (ECB) or matting.
•
Vegetation located down-slope of the work site assists in filtering out sediment. Where practicable, maintain
kerb vegetation such as grass and turf strips in a healthy state during the building process.
STOCKPILES
✕
•
Stockpiles and building materials should not be stored
on the footpath or within the road reserve. Permission
must be obtained from your Council to store materials
in these areas otherwise fines may be imposed.
•
Minimise stockpile losses with the use of covers.
•
All stockpiles and building materials should be located
within the sediment control zone, for example up-slope
of a sediment fence.
•
Stockpiles must not be located within an overland flow
path.
Stockpiles without protection
SERVICE TRENCHES
Backfill service trenches, cap with topsoil, and compact to a level at least 75-100 mm above the adjoining ground
level (either manually or with a small machine). This allows for some subsidence of the fill material, and ensures the
fill is sufficiently compacted to avoid erosion at a later time. (Note that trenches must be backfilled in accordance
with AS3500).
EROSION CONTROL BLANKETS OR MATTING
Erosion control blankets or matting can be used to minimise
soil erosion and stormwater pollution from sites by:
•
containing high erosion risk soils
•
stabilising steep slopes.
SITE REHABILITATION
All areas disturbed by building activities should be promptly
and progressively stabilised, using techniques such as
revegetation and landscaping, so they no longer act as
sources of sediment.
✓
MULCHING AND GARDEN BEDS
To minimise soil loss, mulch should be applied to open
garden beds at a depth of 75-100 mm.
Rehabilitate the site promptly to reduce the chances
of further erosion
This will assist in plant establishment, minimise water
loss and help to control weeds.
Ensure that mulch is stabilised on unstable slopes (e.g. batters and riparian areas) to avoid it washing away and
ultimately entering waterways.
4
Sediment control
SEE FACT SHEET 4
STABILISED ENTRY/EXIT POINT (RUMBLE PAD)
•
Manage entry/exit point (rumble pad) so that sediment is not tracked
off the site.
•
Restrict site access to one stabilised location.
•
Recommended construction method for stabilising access points
is a 150-200 mm deep pad of minimum 40 mm crushed rock.
•
The pad should be at least 2 metres wide and extend from the kerb
to the building slab.
•
Where the entry/exit pad slopes towards the road, a 200 mm high bund (hump) should be installed across the
pad to deflect stormwater run-off to the side where it can be filtered by a sediment fence.
✓
Stabilised gravel entry/exit point (rumble pad)
Note: The location of the permanent driveway may not be an appropriate location for the construction entrance.
SEDIMENT BARRIERS/FENCES
•
Install sediment barriers along the lower
side of the soil disturbance.
•
The most efficient sediment barrier for
building sites is specially-manufactured
geotextile sediment fencing.
•
Sediment fences on building sites
are usually wire-tied to steel or hardwood
posts (wire-tied sediment fences have the
advantage of being more readily unhooked
from their support posts).
•
The support posts are spaced no greater
than 2 metres apart and the sediment
fence buried to a depth of 200 mm.
✓
Sediment fence
•
For public safety and sediment control
efficiency, sediment barriers should not be
located outside property boundaries without Council approval.
•
Sediment barriers should only be placed on the road as a last resort.
•
Sediment barriers placed in front of roadside stormwater inlets are rarely as effective as onsite controls and
at best usually result in the sediment being washed down the street and into the nearest open gully inlet.
•
Only use proper geotextile sediment fence fabric. Don’t use filter cloth or shade cloth.
USE OF SIGNS
Public signs that warn of the need for proper sediment control devices and
maintenance are becoming more widely used. Contact your council for further
information.
✓
Sediment control information signage
5
MAINTENANCE OF CONTROL MEASURES
All erosion, sediment and drainage control measures need to be regularly
checked and maintained in good working order. Best practice includes
anticipation of potential risks and being prepared for abnormal
circumstances and emergencies. These measures include:
•
Stockpile extra sediment fence fabric and posts on-site to facilitate
emergency repairs.
•
Reapply crushed rock to the entry/exit pad (rumble pad) when
sediment build-up occurs.
•
Repair eroded drainage channels with rock, turf or erosion control
blankets or matting.
•
Ensure built-up sediment is removed at regular intervals from
sediment barriers.
•
Check and replace/repair sediment barriers daily if they are ripped,
damaged or no longer anchored.
✓
All measures require regular inspection
✓
Drainage control
Excessive sediment deposits must be removed
from entry/exit point (rumble pad) and
additional crushed rock applied
SEE FACT SHEET 5
DIVERSION OF UP-SLOPE WATER
•
Where practicable, divert up-slope water around the disturbed area.
•
Stormwater can be diverted with the use of small turf or geotextile lined catch drains, or with the use of
diversion banks.
•
Diverted stormwater should be discharged onto stable ground (for example turfed areas) and should not
be diverted into neighbouring properties unless written permission is obtained from the land owner(s).
EARLY ROOF WATER CONNECTION
• Temporary or permanent downpipes should be installed as soon as
practicable after the roof is laid.
• Early connection of roof water to the stormwater system will reduce site
wetness and the generation of on-site mud. This has been shown to
reduce downtime following storm events and decrease the average
building construction time.
✓
Temporary roof water connection
6
Building operations
SEE FACT SHEET 6
Prior to commencing building work
•
Obtain all necessary permits, licences and approvals.
•
Prepare a site specific Erosion and Sediment Control (ESC) Management Plan and have all necessary
ESC materials available.
•
Avoid clearing vegetation and excavating until ready to build.
•
Where necessary in new estates, temporary revegetation may be required.
Points to consider as part of building operations
•
Tool and paint washing, brick, tile or masonry cutting and water-cooled cutting activities should be done
within the property boundaries.
•
All waste water should be contained on-site where possible.
•
Activities should be carried out on a permeable surface or up-slope of an infiltration trench.
•
Vehicles should not be parked on the footpath area or verge where they can damage essential vegetation
and transport dirt onto the road.
•
Contain waste concrete washed from trucks, mixers and barrows on site; do not wash out into stormwater
systems as this can clog drains and cause flooding during storm events.
LITTER AND BUILDING WASTE
All hard waste should be stored on-site in a way that prevents material loss caused by wind or water. Smaller
materials such as litter should be contained in covered bins or litter traps formed on three sides by a geotextile
wind break or similar device.
When travelling to and from the site, secure load to prevent wind blown litter polluting our waterways and roadsides.
✕
✓
One way to properly store building waste
Poor litter and building waste storage
SITE CLEAN-UP
Remove accidental spills of soil or other materials from the road,
gutter or any location outside the control of the primary sediment
barrier:
•
immediately if it is raining or likely to rain during the day
•
at least upon completion of the day’s work (even if rainfall is
unlikely during the night)
•
use a broom and shovel instead of hosing to clean hard surfaces.
•
clean up food packaging after meal breaks as this litter can enter
stormwater systems and waterways.
Following storms, the road reserve and sediment barriers should be
inspected and excess sediment residue removed.
7
✓
Undertake regular site clean-ups
CONCRETE MIXER CLEAN-UP
Fully contain concrete waste washed from trucks and mixer units on-site and store where it cannot be washed from
the site, harming the environment.
EXPOSED AGGREGATE CONCRETE SURFACES
•
Builders need to demonstrate how they intend to prepare exposed aggregate surfaces without allowing cement
residue to flow into stormwater drains or waterways.
•
Where practicable, wash cement residue onto pervious surfaces or fully contain it within temporary sediment
dams created from tightly stacked sand bags.
•
When suitably dry, shovel cement residue into a waste disposal bin.
•
At no time should cement residue or wastewater run-off enter the roadside gutter.
This may make it impractical on some sites for exposed aggregate driveways to be constructed. In such cases,
an alternative driveway finish must be used.
Storage of materials on hard surfaces
SEE FACT SHEET 7
Whenever possible, materials should be stockpiled within the sediment
control zone and, where necessary, covered with waterproof sheeting to
minimise the potential for transport of sediments in stormwater.
Materials may be temporarily stored on hard surfaces only where it is
necessary to place erodible material on hard surfaces to undertake
work and no other reasonable options are available.
✕
Don’t store stockpiles on hard surfaces without
suitable protection
SEE FACT SHEET 8
When one builder controls more than one building lot, combined-lot sediment control structures may be placed
down-slope if:
•
the combined sediment control measures provide a level of protection at least equal to that provided by
individual lot protection
•
The builder accepts responsibility for the ongoing monitoring and maintenance of sediment control devices
•
suitable drainage and erosion control measures are applied to each building lot
•
a suitable sign is placed in a prominent location outside each lot and/or at the entrance of the
estate indicating such controls are in place.
8
Erosion and Sediment Control Management Plans
SEE FACT SHEET 9
Where appropriate, discuss the submission of a management plan with the appropriate building control body.
These plans need to communicate to all - builders, subcontractors, private certifiers, home owners and regulators
involved in the building – how stormwater pollution will be controlled on the site.
EROSION AND SEDIMENT CONTROL INSTALLATION SEQUENCE
1.
Establish a single stabilised entry/exit point (rumble pad).
2.
Install sediment fence(s) along the low side of the site.
3.
Divert up-slope water around the work site and appropriately stabilise any drainage channels.
4.
Clear only the areas necessary (maintaining vegetation on footpath).
5.
Stockpile topsoil within the sediment control zone.
6.
Stabilise exposed earth banks (for example, with vegetation or erosion control blankets).
7.
Install on-site waste receptacles (mini-skips, bins, wind-proof litter receptors).
8.
Install roof downpipes as soon as practicable after the roof is laid.
9.
Ensure that all control measures are maintained in good working order.
10. Revegetate or otherwise stabilise the site.
✓
•
•
•
•
Stockpile is located behind the sediment fence
Good site planning
Turf strip well maintained
Sediment fence well constructed and in correct
location
✕
•
•
•
Stockpile has not been placed behind the sediment fence
Building waste and litter has not been placed in the skip
Poor site planning and management
Note: Diagrams and selected photos courtesy of Catchments & Creeks Pty Ltd.
9
SUPPORTED
QMBA
Queensland Master
Builders Association
417 Wickham Terrace
Brisbane QLD 4000
Ph: (07) 3404 6444
Fax: (07) 3832 2361
www.masterbuilders.asn.au
BY
HIA
Housing Industry
Association Ltd
PO Box 3573
South Brisbane QLD 4101
Ph: (07) 3846 1298
Fax: (07) 3846 3794
www.hia.com.au
Copyright 2006
These guidelines are protected by Australian copyright law.
For permission to use any of the material, contact the
Brisbane City Council or Gold Coast City Council. Some photographs
and drawings are owned by Catchments & Creeks Pty Ltd.
Sediment from building sites is choking our local
creeks, rivers and marine systems. It is vital that erosion
and sediment controls are in place on building sites to
reduce the amount of sediment and other pollutants
entering the waterways.
www.healthywaterways.org
All of us – homeowners, government and the building
industry – have a role to play in protecting our waterways.
Play your part – check and maintain controls daily.
Moreton Bay
on your building site
Healthy Waterways: Fact Sheet
1
EROSION AND SEDIMENT CONTROL
DAILY SITE CHECK LIST
Location of site
Site Supervisor
It is suggested that the site supervisor completes the following checklist daily while site work occurs.
TIMING
Completion
Roof laid
Each day –
throughout the
duration of
works
Start of works
ITEM AND/OR LOCATION TO CHECK
a. Have the tradespeople and suppliers been made aware of the
requirements for erosion and sediment control, and the consequences
involved if there is a breach?
b. If required, has an Erosion and Sediment Control Management Plan been
prepared and approved?
• Are all contractors and subcontractors aware of the contents of this plan?
c. Is the builder’s sign displayed?
d. Are the sediment fences erected adequately/correctly?
NOTE:
• Geotextile sediment fence buried at least 200 mm below ground.
• Posts installed at minimum 2m spacing.
• Built up sediment should not exceed 1/3 of the height of the sediment fence.
• No tears or rips.
• Not laying down or covered over by materials.
• Is there an advisory/attention sign on the sediment fence?
e. Is the stabilised entry/exit point (rumble pad) in the correct location?
NOTE:
• Are all tradespeople/suppliers using this entry point?
f. Does the entry/exit point (rumble pad) require maintenance?
NOTE:
• Has the entry/exit pad got excessive sediment in it?
• Turn over with a machine to expose the coarse aggregate again.
• Aggregate must be 40 mm or greater.
• Is there a bunding/diversion drain above the stabilised entry/exit point
(rumble pad) to divert sediment behind the sediment fence?
• Are the tradespeople using an adjacent lot to gain entry to the site?
If so, has permission been sought from the land owner(s) and are there
control measures in place to prevent the movement of sediment off the
lot and into the gutter?
1
1
EROSION AND SEDIMENT CONTROL DAILY SITE CHECK LIST
TIMING
Completion
Roof laid
Each day –
throughout the
duration of
works
ITEM AND/OR LOCATION TO CHECK
Start of works
g. Is the road clean of sand, silt and mud?
NOTE:
• Do the tradespeople have the capacity to clean-up the sediment
before they leave the site?
h. Is there a contained area for building waste on site?
NOTE:
• Use a skip bin and/or mesh trap.
• Cover the waste cage/bin at the end of each work day.
• Place food packaging into waste cage/bin after each meal break.
• Skip or waste cage should not be allowed to overflow.
• Cover loads of waste when delivering to waste facility.
i.
Are filter socks/sand bags in place?
j.
Are the stormwater gully traps in front of the site protected from sediment
run-off, well maintained, safe for the public and approved by council?
k. Are the ‘wet trades’ setting/washing up behind a sediment fence
and on grassed areas that will hold the volume of waste?
l.
Are the stockpiles/sand/soil adequately protected?
NOTE:
• Covered by a plastic sheet.
• Located behind a sediment fence.
• Sand bags around base.
m. At the end of each working day do the temporary stockpiles on hard surfaces have:
• a bund wall of sandbags, fibre or geotextile sausage on the downslope of the stockpile?
• a waterproof / windproof covering?
• an up-slope diversion of sandbags, fibre or geofabric sausage for on-site stockpiles?
• sandbags or geotextile bags filled with gravel surrounding the stockpile (if on road reserves)?
n. Are the grass/turf strips on the footpath cleared of sediment, sand and mud?
o. Are the service trenches backfilled?
p. Are the temporary downpipes correctly connected?
q. Is there an exposed aggregate driveway? If so, does the concretor
know/practice the correct control measures?
r.
Has the client been advised about erosion and sediment control requirements?
NOTE:
• The site must have adequate control measures on-site at all times,
even after hand over.
For further information about the Healthy Waterways Campaign and The Partnership telephone (07) 3403 4206 or visit the Healthy Waterways website at www.healthywaterways.org
SUPPORTED BY
2
ON RESIDENTIAL BUILDING SITES
Impacts of stormwater pollution
Stormwater contains many pollutants which can enter our local creeks, rivers and marine systems, causing harm
to native animals, plants, fish breeding habitats and recreational areas.
Soil erosion, sediment and litter from building sites can be major sources of stormwater pollution, and can cause:
• significant harm to the environment eg. loss of valuable seagrass habitat for marine creatures
• weed infestation of waterways caused by sediment settling on the creek beds and transporting nutrients
• loss of valuable topsoil
• significant public safety problems when washed onto roads and intersections
• blocked drains creating flooding and increased maintenance costs to the community
• damage to recreational fishing and the seafood industry.
Stormwater is not wastewater
Stormwater is not wastewater. Stormwater flows untreated into the waterways that provide vital habitats for
animals and plants. It is your responsibility to help keep stormwater pollution-free.
Erosion and sediment control on building sites
Soil erosion on building sites can be a major source of sediment pollution in our waterways. A single
building block can lose up to four truckloads of soil in one storm. Sediment, washed from building sites
into gutters and stormwater drains, can cause flooding and affects the water quality and fish stocks in our
freshwater and marine environments.
Effective on-site erosion and sediment control provides many benefits:
• all-weather site access
• improved wet weather working conditions
• improved drainage and reduced site wetness
• less mud and dust problems
• reduced stockpile losses
• reduced clean-up costs
• better public image
• better looking, more marketable sites
• fewer public complaints
• reduced risk of fines
• better fishing for everyone
✓
• cleaner waterways.
Effective on-site erosion and sediment control
1
Stormwater pollution pre
HERE’S WHAT YOU CAN DO TO REDUCE EROSION A
The following site management practices will minimise s
MINIMISE DISTURBANCE WHEN EXCAVATING
Preserve as much grassed area as possible. These areas not only
improve the appearance of your site, they also reduce soil erosion
and filter much of the sediment from stormwater run-off before it
reaches the drainage system.
CATCH DRAINS AND
PERIMETER BANKS
Where possible, allow for
diversion of up-slope stormwater
around the work site and other
disturbed surfaces.
CONCRETE WASTE
AND WASHING
Waste concrete and
household paint must not be
allowed to wash into the
gutters or the street.
INSTALL A SEDIMENT BARRIER
Sediment barriers down-slope of the
building site trap coarse sediment
before it can wash into gutters, drains
and waterways. Sediment barriers can
be made from geotextile sediment
fabric attached to posts with the
geotextile buried in an up-slope trench.
Penalties
Breaches of the legislation may result in:
• on-the-spot fines under the Environmental Protection (Water) Policy 1997 (ie. $300 to $600)
• prosecutions under the Integrated Planning Act 1997 or the Environmental Protection Act 1994
(ie. fines of thousands of dollars or prison sentences for serious offences).
2
evention – it’s up to you!
AND PREVENT SEDIMENT FROM LEAVING YOUR SITE.
soil erosion and sediment run-off from your building site.
ENTRY/EXIT POINT (RUMBLE PAD)
Restrict vehicle access to one entry/exit point
where possible. Stabilising the access with
rock will allow all weather access and will
reduce the amount of soil carried off the
site by vehicles.
EARLY STORMWATER DRAINAGE
CONNECTION
Connect temporary or permanent
downpipe/s to the underground
stormwater system immediately after
the roof is laid – or slow and spread the
flow from downpipes to avoid localised
erosion. Downpipes may be temporarily
removed during wall construction.
All stormwater should discharge in a
manner that does not cause soil erosion.
SAND AND SOIL STOCKPILES
Stockpiles should be placed wholly
on the construction site and behind
a sediment barrier.
Who can be fined on a building site?
Anyone who does not comply with the duties mentioned above can be
prosecuted or issued with on-the-spot fines. Companies, builders, subcontractors
and individual workers can all be fined.
3
2
ON RESIDENTIAL BUILDING SITES
Queensland environmental law
ENVIRONMENTAL PROTECTION ACT 1994
All Queenslanders have a legal duty under the Environmental Protection Act 1994 to take all
reasonable and practicable measures to minimise or prevent environmental harm. Such harm can be
caused if sediment from building sites enters stormwater drains or waterways.
In addition, people who are concerned with management in a corporation have an additional duty under
the Environmental Protection Act 1994 to ensure their corporation complies with the Act. This means
supervisors need to take reasonable and practicable steps to ensure that the people under their control
do not breach environmental laws.
People who become aware of environmental harm in association with their work (eg. loss of sediment from
their site into a watercourse) have a legal duty under the Environmental Protection Act 1994 to notify their
employer. The employer must then rectify the problem, or risk prosecution.
ENVIRONMENTAL PROTECTION (WATER) POLICY 1997
This policy sits under the Environmental Protection Act 1994. The Environmental Protection (Water) Policy
1997 provides for specific offences relating to the deposit and/or release or potential release of sediment
or building wastes to stormwater drains, roadside gutters and Queensland waters eg. creeks and waterways.
Builders waste has the potential to be released into stormwater drains, and is governed by these laws.
THE INTEGRATED PLANNING ACT 1997
The Integrated Planning Act 1997 is the mechanism for assessing all developments within Queensland.
This Act establishes the process for integrated planning and development assessment in an ecologically
sustainable way. Under the Integrated Planning Act 1997 it is a serious offence to breach development
conditions eg. those dealing with erosion and sediment control or stormwater quality.
Other approvals
Councils in Queensland vary in their
approval requirements. Contact your local
council for further information on which
approvals are required.
Council officer discussing erosion and sediment
control problems on-site
4
SUPPORTED BY
3
EROSION CONTROL
Many sites need large-scale earthworks before
building starts. These earthworks should be
limited to the minimum required, and should
only start immediately before building. Topsoil
should be stockpiled on-site for later use.
Grass filter
Kerb
Preserve as much soil coverage as possible.
Figure 3.1
Grass, leaf litter, gravel and erosion control
Maintain grassed areas to reduce erosion
blankets or matting can all prevent rain from
turning exposed soil into mud. The impact of
raindrops on exposed soil can significantly increase the turbidity of stormwater run-off.
Road
✓
Grassed areas down-slope of the work site can help minimise erosion. Where practicable, maintain kerb
vegetation in a healthy state during the building process (refer Figure 3.1).
Stockpiles
Stockpiles and building materials are
not allowed to be stored on the
footpath or within the road reserve,
unless approved by your council.
Stockpile losses can be minimised by
using covers. All stockpiles and building
materials should be located within the
sediment control zone (the area upslope of a sediment fence or other
appropriate sediment barrier).
✕
The stockpile must be located behind the sediment fence
© Catchments & Creeks Pty Ltd
Perimeter bank
Stockpile
Sediment fence
✓
Figure 3.2
Perimeter banks can be used to
divert stormwater around a stockpile
To minimise erosion and the loss of sand and soil, stockpiles should not
be located within an overland flow path. If it is impractical to avoid
stormwater run-off being directed to a stockpile, a flow diversion bank
should be constructed up-slope of the stockpile to direct run-off in a
controlled manner around the stockpile (refer Figure 3.2).
If the placement of erodible material on a road surface is necessary to
undertake work and no other reasonable options are available, the
materials must be removed immediately if rainfall is imminent or
occurring. Otherwise, it should be removed before the end of the day’s
work. Road surfaces should be cleaned with a shovel and broom but not
washed clean (refer Fact Sheet 6).
1
Minimise disturbance
3
EROSION CONTROL
Erosion control blankets
Direction
of flow
✓
Figure 3.3
Erosion control blankets can minimise soil erosion
On soils with a high erosion risk, and on steep sites
when there is a delay in building works or site
rehabilitation, erosion control blankets or matting can be
used to minimise soil erosion and the pollution of
stormwater (refer Figure 3.3). Erosion control blankets or
matting are also suitable when revegetating slopes
steeper than 4(H):1(V), unless well-anchored turf is used.
There is a wide variety of erosion control blankets on the market.
Generally a 100%-biodegradable blanket is suitable for most building
sites, unless the blanket is used to protect a steep overland flow path.
Service trenches
To avoid unnecessary soil erosion, service trenches should be backfilled,
capped with topsoil and compacted to a level at least 75-100 mm above
the adjoining ground level (either manually or with a small machine) as
soon as possible.
This practice allows for some subsidence of the fill material, and ensures
the fill is sufficiently compacted to avoid erosion at a later time.
(Note that trenches must be backfilled in accordance with AS3500).
Service trenches should always be
backfilled, capped with topsoil and
compacted
Site rehabilitation
All ground disturbed by the building
activity should be quickly and progressively
stabilised (for example, by revegetating) so
that it can no longer act as a source of
sediment. Turfing is the most effective form
of site stabilisation. Grass seeding may also
be used, but is less effective than turfing.
Garden beds
✓
Mulch should be applied to open garden
beds to minimise unnecessary soil loss.
Mulch placed at a depth of 75-100 mm will
help to establish plants, reduce water losses
and control weed growth.
Prompt revegetation and landscaping is essential
2
SUPPORTED BY
4
SEDIMENT CONTROL
A combination of sediment control measures is often needed on an individual site. Sediment controls
usually consist of a sediment barrier installed along the lower side of the soil disturbance, and a stabilised
entry/exit pad (rumble pad).
Stabilised entry/exit point (Rumble pad)
Where possible, manage the entry/exit point of the site so that sediment is not tracked off the site.
Where practical, restrict the entry/exit point to one stabilised location, not necessarily at the location
of the permanent driveway (refer Figure 4.1).
Stabilised Entry/Exit Pad – Building Sites
Minim
um len
gth 10
m (min
)
200mm (min)
150–200mm (min)
Runoff from pad
directed to
sediment trap
Geotextile filter cloth
(as directed or when
working on clayey soils)
Runoff diversion bund
incorporated into the pad
when the entry/exit pad is
located down-slope of the
soil disturbance
Width 2.0m (min)
40–75mm
crushed rock
Make safe
for pedestrian
traffic
Footpath
Kerb
Roadway
Figure 4.1
Stabilised entry/exit detail
✓
Direction of stormwater runoff
Runoff
diversion
bank
Entry/exit pad extends
from kerb to building slab
where practical
Building Site
✓
Sediment fence
Footpath
Figure 4.2
Road
Make safe for
pedestrian
traffic
Entry/exit bund detail
A rumble pad may be used to stabilise the entry/exit point. These pads should be at least 2 metres wide
consisting of minimum 40 mm crushed rock placed 150–200 mm thick over geotextile filter cloth. Where
possible, the rumble pad should extend from the kerb to the building slab or a minimum length of 10m.
Where practical, the rumble pad should extend from the kerb to the building slab. Where necessary, 20 mm
aggregate or blue metal should be placed
over the crushed rock between the
property boundary and the road kerb to
make the entry/exit point (rumble pad)
safe for pedestrian traffic.
✓
Where the entry/exit point (rumble pad)
slopes toward the road, install a minimum
200mm high flow diversion bund across
the pad to deflect stormwater run-off into
the main sediment control zone or into
a separate U-shaped sediment fence.
(refer Figure 4.2).
Stabilised entry/exit point (rumble pad)
1
Sediment fences
700mm
(max)
Sediment fences cannot be used to retain
building waste and rubble
✓
✓
Undisturbed
area
200mm
✕
Sediment
fence fabric
Disturbed
area
Sediment fence
return
2m (max) without wire
mesh backing
Direction of flow
Figure 4.3
Typical sediment fence installation
The most efficient sediment barrier for building sites is usually a specially manufactured geotextile
sediment fence. The use of filter cloth or shade cloth is not permitted (refer Figure 4.3).
Sediment fences on building sites can be stapled to
approximately 40 mm square hardwood posts or wire
tied to steel posts. Wire-tied sediment fences have the
advantage of being more readily unhooked from their
support posts during working hours to allow the
unloading of materials. This feature is useful on small
frontage building sites where site access is limited.
In areas where it is impractical to bury the lower edge
of the sediment fence, the lower 200 mm (min) portion
of the fabric should be placed on the ground up-slope
of the fence and buried under a 100 mm (min) layer of
coarse aggregate (20-40 mm) (refer Figure 4.4).
With trench
Without trench
Post
Fabric
Fabric
Aggregate
Back fill
200mm
Figure 4.4
Soil
Alternative sediment fence installations (with and without
a trench)
Sediment fences should be
located down-slope of the
disturbance, and ideally along a
line of constant land level to
prevent the concentration of
stormwater run-off. Where this
cannot be achieved then sections
of the sediment fence should
have ‘returns’ directed up slope
for 1-2 metres to control the
concentration of stormwater
run-off.
✕
Sediment fences require checking and maintenance at the end of each day
2
✕
✓
Poorly maintained or inappropriately located
sediment fences can lead to sediment entering the
stormwater drain
Well designed and maintained sediment fence
Grass filter strips
Grassed areas or grassed filter strips (narrow strips of turf) have generally not proven to be effective in the
capture of sediment from urban residential building sites. At best these areas should be used as a
secondary sediment barrier in partnership with a sediment fence. The main benefit of maintaining grass on
and around a building site is to help reduce soil erosion in the first place.
Grass filter strips are often placed adjacent to road kerbs and footpaths during the subdivision stage of a
new estate. All reasonable and practicable efforts should be taken to minimise damage to this or any
established grass in or around a building site.
Vegetated buffer zones
In rural residential areas, building sites are often surrounded by large areas of grassed or vegetated land.
Such land may be used as the primary sediment barrier if it:
•
•
•
•
•
is down-slope of the soil disturbance
is fully contained within the property
does not contain any drainage swales that may concentrate stormwater runoff
is at least 15 metres long (in the direction of flow)
contains established grass that fully covers the soil
The minimum recommended length (in the direction of flow) of a grassed buffer zone is:
Slope of grassed buffer (%)
0–3
4
5
10
Minimum length (metres)
15
20
25
50
Field inlet sediment barriers
Sediment controls for stormwater inlets located within the property may consist of geotextile fabric placed
either directly over the grated inlet or around the inlet supported by a timber frame.
Field inlet protection is necessary where these inlets drain areas of bare and unprotected soil.
During storms, ponding should be allowed to occur around the stormwater inlet to assist in the settling-out of
sediments. A structurally sound support frame is needed to withstand the weight of sediment-laden water.
Ensure that the type of sediment barrier used does not divert sediment laden water elsewhere without being
treated by a sediment control device.
3
4
SEDIMENT CONTROL
Roadside gully inlet sediment barriers
For safety reasons and sediment control efficiency, sediment barriers generally should not be located
outside property boundaries without Council approval. This especially applies to sediment barriers placed
on the road. Sediment barriers placed in front of roadside stormwater inlets are rarely as effective as onsite
controls and at best usually result in the sediment being washed down the street and into the nearest
open gully inlet. They should only be used as a last resort (refer Figure 4.5 and 4.6). If a roadside gully
inlet barrier is to be installed, then it should not fully block the inlet structure.
Sandbags overlap
onto kerb
4.0m (min)
On-Grade Gully Inlet
Sandbag spacer
Sediment pond
Run-off
Spillway
Bypass flow
Sag Gully Inlet
Gully inlet remains open
to control local flooding
and drainage
✓
Figure 4.5
A roadside on-grade gully inlet sediment barrier. On a hillside,
sediment barriers may consist of a temporary dam constructed
from sand or gravel filled bags placed at least 4 metres
up-slope from the gully inlet. Fabric should not be placed
across the grate or gully inlet.
Geotextile filter sock
Figure 4.6
✓
Roadside sag (low point) gully inlet only. At road sag points, a
sediment barrier may be constructed around the gully inlet, but
should not block the inlet.
Maintenance of control measures
All sediment control measures need to be regularly checked and maintained in good working order.
Best practice includes anticipating potential risks and being prepared for abnormal circumstances
and emergencies. This should include stockpiling extra sediment fence material on-site to facilitate
emergency repairs.
Replace sediment fences if the fabric is ripped or otherwise damaged. The maintenance of sediment
fences includes the removal of sediment deposited up-slope of the fence and, where necessary,
re-trenching the fabric and ensuring posts are firmly secured in the ground.
If excessive sediment build-up occurs, reapply crushed rock to the entry/exit pad.
✓
Regular maintenance of sediment control devices is required
✓
4
SUPPORTED BY
5
Diversion of up-slope water
Where practicable, or where stormwater run-off from more than 0.5 ha feeds into the work site, divert
up-slope water around the soil disturbance. Stormwater can be diverted with the use of small catch drains
or perimeter banks (refer Fact Sheet 3). Line all high flow velocity drains with turf or a geotextile fabric to
avoid unnecessary soil erosion
(refer Figure 5.1).
300mm (min) depth
Direction
of flow
Figure 5.1
1
2
Batter grade
(max)
Channel stabilisation
as required
✓
Diverted stormwater should
be discharged onto stable
areas and should not be
diverted into neighbouring
properties, unless written
permission is obtained from
the land owner(s). Avoid
directing stormwater towards
the site’s entry/exit point
(refer Figure 5.2).
✓
DRAINAGE CONTROL
Divert stormwater around disturbed area
Property Falls Towards Road
12
Property Falls Along Road
13
12
FALL
11
13
14
15
BUILDING
BUILDING
10
Stockpiles
Stockpiles
FALL
Figure 5.2
Road
✓
Road
Examples of how to divert stormwater run-off around the disturbed areas
1
5
DRAINAGE CONTROL
Check dams
Soil erosion in unlined diversion drains can be controlled with the use of check dams constructed from
sand or gravel filled bags. Space the check dams so the crest of the down-slope dam is level with the base
of the up-slope dam (refer Figure 5.3).
Check dam
Geotextile splash pad (optional)
✓
Figure 5.3
Check dams
Roof water connection
The early connection of roof water to the stormwater
system will reduce site wetness and the generation of
on-site mud. Temporary or permanent downpipes
should be installed prior to frame inspection and as
soon as practicable after the roof is laid.
This practice has been shown to reduce downtime
following storm events and decrease the average
building construction time.
✓
✓
Temporary roof water connection
2
SUPPORTED BY
6
BUILDING OPERATIONS
Building operations
Prior to commencing building work
• Obtain all necessary permits, licences and approvals.
• Prepare a site specific Erosion and Sediment Control (ESC) Management Plan and have all necessary
ESC materials available.
• Avoid clearing vegetation and excavating until ready to build.
• Where necessary in new estates, temporary revegetation may be required.
Carry out building operations such as washing tools and painting equipment, and cutting bricks, tiles or
masonry within the property boundaries.
Where practicable, these activities should be done on a permeable surface (eg. grass, infiltration trench or
loosened soil) where pollutants can be contained on-site. This is important for water-cooled cutting
equipment that can generate significant quantities of polluted wastewater.
Material delivery and storage
When ordering erodable materials (eg. soil, sand, mulch), provide clear instructions on where the materials
should be delivered within the site. The stockpile area should be clearly marked on the site.
Erodable materials mistakenly placed within the road reserve (including accidental spillage and the
tracking of such materials onto the road) that cannot be prevented through reasonable means, must be:
• removed immediately if rainfall is imminent or occurring
• removed prior to the end of the day’s work even if rainfall is not expected.
Litter and building waste
All solid waste should be correctly stored on-site to prevent it from leaving the site either by the effects of
wind or water.
Smaller materials such as litter, should be contained in covered bins or litter traps formed on three sides
by a geotextile wind break or similar device.
✓
One method to store litter and
building waste
✓
✓
Skips and ‘Reo’ cages are other ways to store building waste
1
6
BUILDING OPERATIONS
Site clean-up
Remove accidental spills of soil or other materials on the road or in the gutters or drains before rainfall and
at least on completion of the day’s work. Sweep materials from the road – don’t wash them down the gutter.
Following storms, inspect the road reserve and all sediment barriers and remove any sediment residue.
Inspect all other erosion and sediment control measures, and make any necessary adjustments to improve
their operation during the next storm.
✓
✓
Regular site clean-up is required. Use a broom (not a hose) to sweep roads and paths
Concrete mixer clean-up
Contain concrete waste washed from trucks and mixer
units on-site. Don’t place it in a position where it could
reasonably be expected to wash from the site and harm
the environment.
Warning – water from cement wash
down activities contains pollution that
can cause fish kills in local waterways.
Ensure this water does not leave the
building site.
Exposed aggregate concrete surfaces
Builders need to determine how they intend to prepare
exposed aggregate surfaces without allowing cement
wash-off to flow into stormwater drains or waterways.
Where practicable, wash cement residue onto pervious
surfaces or contain it within a temporary trench (refer
Figure 6.1).
At no time should cement residue or wastewater run-off
be allowed to enter the roadside gutter. This may make
it impractical for exposed aggregate driveways to be
constructed on some sites. In such cases, an alternative
driveway finish must be used.
Building Site
Length as
necessary to
fully trap
wash-off
Wash cement
towards the
wash-off
collection
trench
Excavated
wash-off
collection
trench
Segment
trench if
constructed
down a
slope
Sandbag flow diversion bank
Footpath
Road
Figure 6.1
The collection trench stops cement wash-off from flowing
into stormwater drains
2
SUPPORTED BY
7
STORAGE OF MATERIAL
ON A HARD SURFACE
Site supervisors must provide adequate facilities for storage and handling of building materials, especially
erodable materials. Failing to appropriately manage the risk of stormwater pollution from your building
site can lead to fines or prosecutions for companies, builders, subcontractors and individual workers.
Stockpiled building materials, such as sand and soil, can be a major source of sediment. These materials
should be stockpiled within the sediment control zone and covered with waterproof sheeting.
Where building materials can not be stored in an area protected by sediment control measures or in a mini
skip, hard surfaces may be used as a temporary measure.
Stockpiling of material on public footpaths and roads may not be permitted. Check with your local Council
as fines may be applicable if stockpiles are placed in these areas without the prior approval of the relevant
local authority.
Stockpile Protection
Prior to the completion of each working day, the following measures to prevent movement of temporary
stockpiles into the stormwater system or waterways by wind, rain or overland flow should be implemented
• sandbags placed on the downslope of the stockpile to prevent movement
• a suitable waterproof/windproof cover to be placed over the stockpiled material
• use sandbags, filter bags or fibre sausages to divert upslope flow of stormwater into the grassed areas
of the site and away from the stockpiled material
On road reserves an approved temporary stockpile should have sandbags or geotextile bags filled with gravel
around the stockpile. Materials placed on the road reserve must not block traffic or cause a safety problem.
Accidental spills or vehicle tracking
If accidental spills or tracking of soil occur on hard
surfaces such as concrete driveways, rumble pads and
public roads then the cleaning methods described
overleaf should be implemented prior to the end of
the working day.
✕
Stockpile not appropriately stored
1
7
STORAGE OF MATERIAL ON A HARD SURFACE
In the event of rain
If it is raining or about to rain while erodible materials are stockpiled on hard surfaces, then all reasonable
and practicable efforts must be taken to prevent or minimise sediment losses from the stockpile.
If the materials cannot be moved to a location where erosion can be prevented and/or sediment
controlled – for example, a well-grassed area – control measures could include:
• covering the stockpile with a waterproof and well-secured cover
• using sandbags or other non-erosive materials to divert up-slope water around the stockpile
• constructing a slightly porous dam downstream of the stockpile to trap sediment.
In the event of rain, roadside sediment collection dams should be constructed up-slope of gully inlets,
but should only be short-term structures (refer Fact Sheet 4).
No device should be used or installed if it is likely to cause a safety hazard. Where safety hazards cannot
be managed (e.g. signage and/or safety barriers) alternative sediment control techniques may be required.
Cleaning methods
Erodable materials must be cleaned from the road or hard surface as soon as possible.
To clean materials from hard surfaces, the bulk of the material should first be shovelled and swept onto an
area enclosed by a suitable sediment barrier (eg. up-slope of a sediment fence). Cleaning the rest of the
material from the surface (in order of priority) can be achieved by using one of the following options.
1. Manually sweeping the material onto an adjacent grassed or open soil surface where sediment controls
are in place. Skid steer loaders (bobcats) with broom attachments may also be used.
2. Use of a vacuum unit (for example hired
street sweeper), where the cost can be
justified.
3. Finally, and only in circumstances if there is a
safety hazard if the remaining material is left
on the hard surface, the material may be
washed from the surface into a temporary
dam formed from slightly porous material
eg. gravel-filled bags or clean aggregate.
After allowing the excess water to drain
from the dam, the retained material should
be collected and disposed of in a location
where it would not be expected to wash
into a drain or waterway. Importantly, only
use just enough water for the job (refer
Figure 7.1).
Building Site
Wash-off from
site and roadway
cleaning
Temporary
sandbag sediment
collection trap
Footpath
Road
ROAD
Figure 7.1
Temporary sediment collection dams should only be used when it is
unsafe to leave materials on the hard surface
2
SUPPORTED BY
8
When more than one building lot is controlled by the builder, then combined-lot sediment control
structures may be placed down-slope of these lots if:
• the combined sediment control measures provide a level of protection at least equal to that provided
by individual lot protection
• suitable drainage and erosion control measures are applied
to each building lot
• the builder accepts responsibility for the ongoing
monitoring and maintenance of sediment control measures
COMBINED-LOT SEDIMENT
CONTROLS ARE IN OPERATION
AT THIS BUILDING SITE
• a suitable sign (where required) is placed in a prominent
For example, the above wording may be used.
location outside each lot and/or at the entrance to the
estate (if all lots within the estate are subject to combined-lot controls)
• the sign must indicate that combined-lot sediment controls apply to this property.
Examples of combined-lot sediment control measures
Street sweeping
On multiple lot developments, regular street sweeping can be used to remove coarse sediment from
roadways (for example at the end of each working day). However, street sweeping should not be used as
an alternative to the placement of rock pads at the entry to each building site.
Street sweeping may not capture some clays, and there will always be a small amount of sediment left on
the road, especially on road surfaces with a coarse texture. If the remaining sediment is likely to cause a
safety hazard, then the material should be washed from the road into a temporary dam formed from
porous material (eg. gravel-filled bags or clean aggregate).
Sediment fence
A sediment fence can be installed along
Spill-through Weir
300mm (min)
A
the lower edge of a combined building
site similar to those on single building
sites. If the total catchment area
exceeds 1500 m2, then a spill-through
weir should be installed at a low point
along the sediment fence. Erosion
control matting may be required downA
Figure 8.1
slope of this weir to control scouring
Sediment fence design for combined or grouped sites
(refer Figures 8.1 and 8.2).
GROUPED BUILDING LOTS
If the catchment area exceeds 1500 m2 and spill-through weirs are not installed, then the sediment fence
may need extra support to prevent it from failing during storms. Extra support can be provided by cross
bracing or by installing the sediment fence up against a permanent property fence. However, the fence
should always be turned slightly up the slope at its lower end(s) to help pond water and prevent the water
from simply flowing around the ends of the fence (refer to Fact Sheet 4).
1
Sediment fence cont…
Spill-through Weir
Weir crest set below minimum ground
level at the ends of the fence
300mm
(min)
Erosion
protection as
required
Sediment trench
A sediment trench is a long trench excavated
along the down-slope side of a work site. Where
practicable, the sediment storage volume of the
trench should be at least 1 m3 for every 200 m2
of catchment area flowing to the trench
(refer Figure 8.3).
Section A-A
Figure 8.2
Spill-through weir (Cross-section A-A)
The purpose of the trench is to capture the bulk
of the sediment before it reaches the sediment
fence. This reduces sediment build-up next to the
fence and reduces maintenance of the sediment
fence (refer Figure 8.4).
In most locations, sediment trenches are only
suitable if they can drain quickly after a storm so as
not to create a safety hazard. Site safety always
takes precedence over sediment control. Collected
water may either filter through the soil (not suitable
for clay soils) or filter through a rock (200 mm) and
aggregate (25 mm) filter dam installed at a suitable
outflow point.
Fabric may be required
to control erosion
Sediment storage trench
1m3 volume per 200m2 of
catchment area
Figure 8.3
Sediment trench
Sediment fence
Lot 1
Lot 2
Lot 3
Fall
Sediment
collection
trench
Figure 8.4
Flow
Road
Rock entry pad
Catch drain
Sediment fence
Sediment trench location for combined or grouped sites
2
Sediment fences on such sites will require more
maintenance than those on smaller sites because of
the increased quantity of sediment that is likely to
be trapped by the fence. To minimise maintenance,
a small sediment collection trench can be excavated
up-slope of the fence.
Support rock
(size 200mm
min.)
A sediment fence is usually installed immediately down-slope
of the trench. Soil excavated from the trench can either be
stockpiled away from the trench, or placed in mounds between
the trench and the sediment fence.
Nom. 25mm
aggregate,
alternatively filter
cloth may be used
200mm
Flow
Rock filter dam
Figure 8.5
Where possible, the sediment trench should be excavated
along the contour.
✓
Rock or gravel filter dam to slow velocity and
help trap sediment
If the trench is constructed down a slope, then rock or gravelbag filter dams should be installed in the trench to control
flow velocities (to prevent scouring) and to help trap sediment
along the trench (refer Figure 8.5). A sediment fence may not
be required next to the trench in these circumstances (refer
Figure 8.6).
Flow
Sediment trench constructed
on a mild slope
Flow
Protect entry
of trench with
geotextile to
control scour
Rock check dam
Figure 8.6
✓
Sediment trench constructed on a slope
Sediment barriers around roadside gully inlets
All reasonable efforts should be taken to fully contain all sediment control measures within the boundaries
of the grouped building lots. Where this is not practical and there is the risk of sediment entering a gully
inlet, then roadside sediment barriers may be installed if:
permission is obtained from the owner of the roadside reserve, usually Council
all gully inlets can be protected from the soil disturbance to the nearest 'sag' point (lowest point) in the road
appropriate 'on-grade' and 'sag' gully inlet sediment barriers are used to protect each type of gully inlet
the sediment barriers do not pose a traffic safety risk.
Sandbags overlap
onto kerb
4.0m (min)
On-Grade Gully Inlet
Sandbag spacer
Sediment pond
Run-off
Spillway
Bypass flow
Figure 8.7
Sag Gully Inlet
to control local flooding
and drainage
✓
A roadside on-grade gully inlet sediment barrier. On a hillside,
sediment barriers may consist of a temporary dam constructed
from sand or gravel filled bags placed at least 4 metre
up-slope from the gully inlet. Fabric should not be placed
across the grate or gully inlet.
Geotextile filter sock
Figure 8.8
✓
Roadside sag (low point) gully inlet only. At road sag points, a
sediment barrier may be constructed around the gully inlet, but
should not block the inlet.
3
•
•
•
•
8
GROUPED BUILDING LOTS
Regional controls
Regional controls are sediment traps that are either installed
during the initial development of a subdivision, or developed by
Council as a form of regional pollution control for completed
urban developments. Examples of regional sediment control
measures include permanent sediment traps, gross pollutant
traps and constructed wetlands (also known as stormwater
quality improvement devices).
Regional controls are designed to manage
stormwater pollution from completed estates.
Use of these as a substitute for site based
erosion and sediment control is generally not
acceptable and is far less effective than
managing soil erosion and sediment pollution
at the site based level.
Most regional controls are primarily aimed at trapping coarse sediment such as sand and coarse silt. But,
the existence of regional controls downstream of a building site does not remove the need for adequate
drainage and erosion and sediment control measures within each building site. Only through effective on
site drainage and erosion control can clays and fine silts be prevented from harming downstream
environments.
If a builder proposes to use regional sediment traps as a form of sediment control, or if sediment controls
are proposed to be installed outside the property boundaries, then consult Council for approval. While
regional controls for sediment control may exist, site-based erosion and sediment control measures are
preferred during building and construction phases. Regional controls are designed to control only the
levels of sediment entering stormwater from a completed estate.
Erosion and sediment control programs
An Erosion and Sediment Control
(ESC) program should be prepared
for all developments involving
combined-lot sediment control
structures (refer to Council’s Erosion
and Sediment Control Management
Plans – Fact Sheet 9) and will require
approval from the developer and
relevant council officer.
✓
Sediment fence and best practice building site
4
SUPPORTED BY
9
MANAGEMENT PLANS
Management plans are given various titles including Erosion and Sediment Control Management Plans
(ESCMP), and Soil and Water Management Plans (SWMP). Where appropriate, the submission of a
management plan needs to be discussed with the appropriate building control body. These plans need to
communicate to all involved – sub-contractors, private certifiers, home owners and regulators – how
stormwater pollution is to be controlled on the site and who is responsible for its control.
Where appropriate, ESCMPs should include, but not be limited to, the following information:
• property boundaries
• general soil description
• existing and final contours – including location of cut and fill banks
• existing and final overland flow drainage paths
• limits of clearing where applicable eg. on large properties
• location of vegetated buffer strips
• stabilised entry/exit point (rumble pad)
• location of soil and sand stockpiles
• location of all proposed temporary drainage control measures
• location of all proposed erosion control measures (alternatively, use notes to describe locations)
including installation sequence and maintenance requirements
• permanent site stabilisation measures
• a statement of who is responsible for establishing and maintaining all erosion and sediment measures.
Installation sequence
The timing of works and the installation of control measures has a major influence on the management
of stormwater.
EROSION AND SEDIMENT CONTROL INSTALLATION SEQUENCE
• Establish a single stabilised entry/exit point (rumble pad).
• Install sediment fence(s) along the low side of the site.
• Divert up-slope water around the work site and appropriately stabilise any drainage channels.
• Clear only those areas necessary for building work to occur.
• Stockpile topsoil within the sediment-control zone.
• Stabilise exposed earth banks eg. vegetation, erosion control blankets.
• Install on-site waste receptacles eg. mini-skips, bins, reo cages. These should be covered to prevent
waste being moved by wind.
• Commence building activities.
• Install roof downpipes as soon as practicable after the roof is laid.
• Maintain all control measures in good working order.
• Revegetate or otherwise stabilise the site.
1
Stockpiles
ROAD
BUILDING
FALL
Stockpiles
BUILDING
ROAD
20
ROAD
ZERO LOT ALIGNMENT
BUILDING
Stockpiles
Stockpiles
PROPERTY FALLS AWAY FROM ROAD
10
11
FALL
13
21
22
15
14
FALL
13
Flow control
bund
ROAD
Stabilised entryexit rock pad
Sediment fence
Drainage control
ROAD
BUILDING
CUL-DE-SAC PROPERTY
Legend:
ROAD
BUILDING
13
Stockpiles
NARROW LOT
FALL
12
FALL
Stockpiles
BUILDING
14
PROPERTY FALLS ALONG ROAD
15
30
31
32
25
26
27
FALL
Sediment fence
Dwelling site
Property boundary
12
Entry/exit pad bund
Level spreader
Contour line
10
11
Vegetation buffer
Sand
stockpile
Material storage area
Topsoil
stockpile
nk and/or catch drain
ROAD
Proposed Dwelling
a diversion ba
Up-slope stormwater runoff
Divert up-slope 'clean' runoff with
ent
nkm
ba
12
Make safe for
pedestrian traffic
Existing
vegetation
or new turf
Option 1:
use of level
spreader to
release the
water as
sheet flow
4. Stockpiles of clayey material to be covered with an impervious
sheet.
2. All ground cover vegetation outside the immediate
5. Roof water downpipes to be connected to the permanent underground
building area to be preserved during the building phase.
stormwater drainage system as soon as practical after the roof is laid.
3. All erosion and sediment control measures to be installed prior
to commencement of major earthworks.
Stabilised
entry/exit pad
Diversion drain/bank
EROSION AND SEDIMENT CONTROL MANAGEMENT PLAN
1. All erosion and sediment control structures to be
inspected each working day and maintained in
good working order.
Notes
Legend
Em
TYPICAL DRANAGE AND SEDIMENT CONTROL LAYOUTS
Option 2: direct concentrated flow down the slope in a lined drain/chu
12
SUPPORTED BY
PROPERTY FALLS TOWARDS ROAD
9
EROSION AND SEDIMENT CONTROL MANAGEMENT PLANS
Sample Management Plans
2

HWW Folder Outside - Healthy Waterways

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