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Coastal and Marine Pollution
Volume 1, Issue 5
Environment Australia, March 2002
Many people consider stormwater runoff a nuisance and want it cleared away as fast as possible. Urban drainage systems were primarily developed to minimise the risk of flooding, however, consideration of natural resource conservation, environmental quality and amenity seems secondary.
In this issue, Stormwater News looks at new approaches to stormwater management which address issues of stormwater quality and aquatic ecosystem health, as well as stormwater quantity. These approaches recognise the environmental impacts of urbanisation, the linkages between land and water management, and the importance of community values and involvement.
For more information on the Urban Stormwater Initiative contact:
Ph: 02 6274 2005
Fax: 02 6274 2268
Email: garry.reynolds@deh.gov.au
Department of the Environment and Heritage
GPO Box 787 Canberra ACT 2601
http://www.deh.gov.au/coasts/pollution/usi/index.html
Some people, often unconsciously, take water for granted and expect it to be available at the turn of a tap or as a steady flow in our rivers. Yet this carefree attitude towards water, and the overuse or misuse of this vital component in our day to day lives, has placed unprecedented pressures on our water resources.
There are challenges and pressures on every part of the water cycle which in turn affect the amount of water harvested from our catchments, the water we drink, and the aquatic life in our oceans and rivers.
To address these challenges, Commonwealth, State and Territory Governments have developed a National Water Quality Management Strategy (NWQMS). The Strategy is based on policies and principles for water quality management that apply nation-wide. A key part of the strategy is a set of guidelines to help implement these new approaches, with guidelines for stormwater also included (Volume 10).
This edition of Stormwater News will explain how the stormwater guidelines, with its view to the future, is taking hold in regions across Australia.
To obtain a copy of the stormwater guidelines or for more information on the NWQMS, visit www.deh.gov.au/water/quality/nwqms/index.html
Manly foreshore with stormwater discharge pipe
Figtree Place is a 27-unit community housing development in Newcastle. What makes it different from most other housing developments is how it uses water-sensitive urban design to capture and reuse stormwater.
The stormwater from roof surfaces is pre-treated in first flush devices and stored in underground rainwater tanks. The catchment runoff from roads and other impervious surfaces is infiltrated through the base of a dry detention basin and stored in an aquifer.
The stormwater is pumped from the aquifer and used to irrigate garden beds and open spaces within Figtree Place. It is also used to wash vehicles at the neighbouring bus depot.
Harvested roof water is also used to supply toilet and hot water services in each housing unit. To ensure the water quality for the hot water services is compliant with drinking water standards, the roof water is pasteurised from the underground tanks prior to its re-distribution.
Monitoring of the harvested stormwater supplied to the units in the housing development indicates it complies with Australian Drinking Water Standards. Overall, the water management scheme at Figtree Place reduces the high-quality mains water demand by nearly 60 per cent.
For further information contact Peter Coombes at pcoombes@mail.newcastle.edu.au
Integration of rainwater management into architectural design for buildings and associated landscaping.
Condamine Court is a public housing redevelopment complex located on Northbourne Avenue, Canberra. Shower, bath and laundry wastewater from the 70 apartments is filtered, then biologically treated for six days in a tank. Depending on the demand, the treated greywater is either used straight away or held in a 120,000 litre underground storage tank.
The water then passes through a sand filter bed which removes any particles that may clog the sub-surface landscape irrigation system. This system recycles 75 per cent of the annual volume of wastewater which is produced from the units.
The stored water is re-circulated over a small waterfall and through a sub-surface wetland where reeds and rushes assist in the process by removing more nutrients.
Condamine Court is an excellent example of a new water management system in a medium density housing development.
The design won an ACTEW water conservation award in 1997, an Australian Water Association (AWA) Water Cycle Management Award and a World Habitat award in 1998.
For more information call Garry Kerans, Integrated Eco-Villages on 02 6297 3401
Improved urban form and subdivision design which integrates stormwater management, greywater re-use and landscaping into the residential block and precinct levels
Homebush Bay, the international showpiece for the Sydney 2000 Olympic Games, boasts more than their outstanding sporting venues and facilities. It also boasts innovative water treatment and conservation measures.
Stormwater run-off from within Homebush Bay is treated using gross pollutant traps, swales and wetland systems. Wastewater is also treated using a water reclamation plant inside the complex.
The treated stormwater and wastewater are stored in a disused brick pit. The treated water is available and used as an alternative water supply for water features, irrigation purposes, toilet flushing and fire fighting within Sydney Olympic Park.
The use of this alternative water resource, combined with water saving appliances, can help reduce mains water use by up to 50 per cent.
For further information contact Warwick Proctor on 02 9714 7260
Modified approaches and techniques used include infiltration, rainwater tanks, grassed swales and wetlands in place of piped drains. These are particularly attractive in situations of greenfield development and urban renewal.
Lynbrook Estate is a greenfield residential development on the south-east outskirts of Melbourne. The entire estate is a 1700 hectare development which incorporates exceptional stormwater management on both the streetscape and sub-catchment scale.
Using part conventional drainage and part water-sensitive urban design (WSUD), the drainage system treats stormwater flows to protect natural waterways.
Planning and design features at Lynbrook Estate include:
The Urban and Regional Land Corporation (URLC) is the estate developer. One of their major concerns was to ensure for marketing purposes, that the WSUD elements of the stormwater system appear as conventional as possible. The local council, in particular, was concerned about community reaction to the function and appearance of the system, as well as its long-term maintenance.
Another challenge for the URLC to overcome was convincing contractors and sub-contractors to embrace the new design without significantly increasing their installation rates and material costs, and meeting quality standards at the same time.
The system costs around the same as conventional drainage to install and has excellent environmental performance. There are significant savings with the system, including the stormwater no longer requiring high levels of treatment before it enters waterways and bays. The system also filters out any litter.
For further information contact Bernie Porter at bporter@urlc.vic.gov.au
Retention of natural streams within the urban areas, or construction of vegetated waterways in place of large pipe or concrete channel drains.
As part of this approach, flood corridors are developed as open spaces and landscape features, which can include wetland and flow detention facilities, ponds and riparian and floodway vegetation, with parklands and pedestrian and cycle pathways.
Waterways can also be used as a water supply distribution system for water supply purposes.
Project Manager of Stormwater News and Champion Rower.
One person who spends a lot of time very close to water is World Champion Rower Jane Robinson. In 2001 Jane won gold in both the Women's coxless four and the coxed eight at the World Rowing Championships in Switzerland.
When Jane is not on the water, she's still thinking about it. Through her employment with environmental consultants Resource Policy & Management she has been working with the Urban Stormwater Initiative to bring you Stormwater News.
Jane first took up rowing on Melbourne's Yarra River in 1993. Rowing on the Yarra mostly takes place near the end of a river that is subject to heavy urbanisation. Gross pollutant traps and projects such as Melbourne's Moonee Ponds Creek Litter Initiative are all contributing towards a cleaner river environment.
In 2000, Jane was able to entertain her Sydney Olympic team mates with stories about the world class stormwater management system integrated into the Homebush Olympic site (see "Storming for Gold" Stormwater News Ed 1). "They were impressed that the Millennium wetlands were functional as well as aesthetic," she said.
For more information about Stormwater News (or rowing) please contact Jane Robinson, Resource Policy & Management (02) 6232 6956.
Cabbage Tree Creek, which feeds into Moreton Bay in south-east Queensland, has been identified as a 'hot spot' for environmental degradation. Stormwater runoff from roofs, gardens and streets that flow through the underground pipes is carrying pollutants into the once healthy creeks which flow into the Bay. Adding to the problem, urban development and the networks of concrete pipes have affected the ponds, pools and wetlands where reeds, rushes and other aquatic plants once grew and supported a rich diversity of wildlife.
Pine River Shire Council's Environmental Planning Officer, Daniel Clowes, said stormwater run-off affects the water quality of creek and gully systems. "When water flows through healthy aquatic ecosystems, the natural processes remove dissolved chemicals and filter out undissolved particles.
"But when stormwater flows through pipes, it is carried unchanged to the end of the pipe system and we therefore lose the water purifying capacity of the natural creek and gully systems," he said.
The Council has recently completed the Cabbage Tree Creek Waterway Enhancement Project which replicates natural processes and removes unwanted pollutants from stormwater before it enters the creek. Mr Clowes said installation of a sedimentation basin and stormwater wetland has resulted in the reduction of nutrient and sediment loads to the creek. Likewise, post-construction monitoring indicates an improvement in downstream ecosystem health.
This project forms part of the Moreton Bay Integrated Stormwater Management Demonstration Project, which has received $970,000 from the Commonwealth Government's Clean Seas Program.
For further information please contact: Daniel Clowes, Environmental Planning Officer, Pine Rivers Shire Council at daniel@prsc.qld.gov.au
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