technical paper River Health

ISSN 2206-1991 Volume 1 No 3 2016 http://dx.doi.org/10.21139/wej.2016.022 THE PARRAMATTA RIVER WATERWAY IMPROVEMENT PLAN

Implementing integrated Water-Sensitive Urban Design (WSUD) stormwater management systems to improve the health of the Parramatta River

T Nadesan

ABSTRACT Wastewater pollution is governed supply city’ towards a ‘water- The Parramatta River Waterway under an Environment Protection sensitive city’ and the key socio- Improvement Plan is a collaboration Licence issued by the Environment political drivers and service delivery between local councils, community Protection Authority; however, functions associated with each phase. groups and NSW Government stormwater remains unregulated. Sydney is currently transitioning from agencies, led by Sydney Water, to No single authority currently leads a ‘drained city’ into a ‘waterways implement integrated Water-Sensitive waterway management in Sydney, city’ (Cunningham et al., 2015). Urban Design (WSUD) stormwater with responsibilities shared by local Traditionally, water quality has management systems to improve councils, State Government agencies been seen as the major indicator the health of the Parramatta River. and private landowners. The Waterway of waterway health. However, as Improvements include, but are not Improvement Plan involved the indicated by Figure 1, urban water limited to, better water quality and collaboration of Sydney Water with management is now shifting its focus enhanced liveability. After consultation stakeholders to agree on project with stakeholders, Sydney Water and locations and to gain the best-value to social and environmental benefits consultant group Alluvium developed outcomes for the community. as well, hence the need for plans such 10 project options. If implemented, as the Parramatta River Waterway the Parramatta River Waterway Current Waterway Health Improvement Plan. Waterways in Sydney include small Improvement Plan will contribute to Recently, Sydney Water has taken upland freshwater streams, lowland Sydney’s transition from a ‘drained steps to improve waterway health freshwater creeks, rivers, estuaries, city’, focused on flood protection, to and liveability through waterway lakes, lagoons, wetlands, harbours a ‘waterways city’ focused on social restoration (or naturalisation) in amenity and environmental protection. and the ocean. The health of these areas where waterway assets waterways will depend on the level of required renewal. INTRODUCTION development in the catchment and the Sydney Water owns wastewater extent and condition of riparian zones. In Sydney Water’s 2016–2020 infrastructure and 447km of stormwater Rivers with urban catchments have more capital program, stormwater quality trunk drainage assets that collect, polluted waterways in comparison to improvement has been proposed in contribute to and convey flows to upland creeks with natural catchments accordance with the Parramatta River receiving waters in the Parramatta River (Walsh et al., 2001). Pollution tends to Coastal Zone Management Strategy. catchment (Cunningham et al., 2015). accumulate on impervious surfaces Sydney Water’s corporate values: Because of this it has a significant and runs off into receiving waters ‘to care for one another, the influence over the river’s health and during periods of rainfall. Examples environment and the community; to its tributaries along with other land of pollutants are included in Table 1. create new and better ways of doing management authorities. The Parramatta Towards A Water-Sensitive City things; and having the customer at the River Catchment Group (PRCG) is heart’ have been another key driver for a group of local councils, community A water-sensitive city is the the Waterway Improvement Plan. groups and State Government agencies, commonly adopted vision for the including Sydney Water, collaborating water industry in Australia. Figure Other key drivers include the Sydney to improve the urban waterway. 1 shows the continuum from ‘water Water Act, Operating Licence and

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community, improve liveability Cumulative Socio-Political Drivers and provide for a healthy ecosystem in the waterway; Water supply Public health Flood Social amenity, Limits on Intergenerational access & protection protection environmental natural equity, resilience • Manage stormwater so that security protection resources to climate change the volume and frequency of stormwater runoff is reduced and runoff quality is improved; Water Supply Sewered Drained Waterways Water Cycle Water Sensitive City City City City City City • Add benefits such as improved amenities and minimised development costs. Adaptive, multi- Diverse, fit-for- functional purpose sources infrastructure & Examples of WSUD include Point & & conservation, urban design Separate diffuse source promoting reinforcing bio-retention systems such Supply sewerage Drainage, pollution waterway water sensitive hydraulics schemes channelisation management as raingardens (Figure 2) and protection behaviours constructed wetlands (Figure 3), Service Delivery Functions which allow for the extended detention

time of stormwater runoff. Pollutants Figure 1. Urban Water Management Transition Framework (Brown et al., 2008). such as total nitrogen and phosphorus Environment Plan, which require Water-Sensitive Urban Design are removed to an extent through Sydney Water to sustainably operate, WSUD is the integration of urban biological uptake. Lastly, stormwater maintain and manage its stormwater water cycle management with urban infiltrates through the soil over time infrastructure. planning (Melbourne Water, 2005). as cleaner runoff as well. Furthermore, the PRCG currently It can be implemented in existing As outlined in Table 2, or new developments and has three has an initiative called Our Living River combinations of primary, key principles: to plan for the regular use of natural secondary and tertiary treatments swimming locations throughout the • Protect waterways so that they are able to capture more of the river in the future. continue to be beneficial for the pollutants from stormwater runoff.

Table 1. Common pollutants in stormwater runoff (Cunningham, 2015). Pollutants Sources What Are Their Impacts? Leaves, grass clippings, human Organic matter Biogeochemical processes (cycling of substances) and animal faeces Impact on visual amenity Litter, coarse sediments, Impact on water quality indicators such as oxygen demand, Gross pollutants organic matter hydrocarbons and heavy metal levels Contributes to blockages of the conventional drainage system Total nitrogen Atmospheric deposition, soil Algal blooms on the water surface Total particles, human and animal Toxic algal blooms cause the closure of fisheries, phosphorus faeces, plant matter, fertilisers water farming industries and public beaches Reduce the penetration of light through water impacting on the respiration of aquatic plants Suspended Soil particles, airborne particles, Sedimentation of receiving waterways solids sediment from erosion Can contribute to blockages of the conventional drainage system Petrol additives, hydrocarbons, Trace amounts old paint (prior to 1970), lead acid Impacts are affected by complex interactions with biophysical of heavy metals: batteries, vehicle wear (tyres), parameters such as pH, dissolved oxygen and temperature lead, zinc herbicides, building materials Bio-accumulation of heavy metals in soils and in various species used on roofs and pavements Impact on visual amenity Mineral oils, automotive oils, Hydrocarbons Can be highly toxic to aquatic life in low to moderate diesel fuel concentrations Sewage cross-connections Pathogens Human and animal health and overflows, animals

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Table 2. Examples of WSUD used in primary, secondary and tertiary treatment (Melbourne Water, 2015). Treatment​ Processes​ Pollutants​ Typical Treatment Application​ Primary Physical screening and Gross pollutants and Grassed swales, litter traps treatment​ rapid sedimentation​ coarse sediment​ and sediment ponds​ Secondary Fine particle sedimentation Fine sediment and Swales, infiltration trenches, porous treatment​ and filtration techniques​ attached pollutants​ paving and bio-retention systems Tertiary Enhanced sedimentation and Nutrients and Bio-retention/bio-infiltration systems treatment​​ filtration, biological uptake and dissolved and wetlands adsorption onto sediments​ heavy metals​

1. Reviewing background information Critical Elements in raingarden design Best location of device adjacent such as the Parramatta River Catchment: area characteristics to land uses and Coastal Zone Management underground Strategy, and also geospatial Site function: users, services maintenance, interpretation data from local councils and utilities including Sydney Water. Sydney Water met with the PRCG to understand the river’s Top layer – vegetation history, current activities and Stormwater inflows (tolerant plant species that cope with dry and the priorities of its members. wet conditions) 2. Meeting with council staff from Extended detention depth across declared catchment areas to identify project opportunities High flow bypass and possible ongoing maintenance options in the future. Sydney Water

Filter/growing media layers: met face-to-face with seven local Second layer – mulch Final layer – councils, while another seven Third layer – filtration media drainage were contacted through Fourth layer – transition conference calls. Discussions Figure 2. A raingarden design example (Clearwater, 2012). began with Sydney Water calling

SEDIMENTATION BASIN MACROPHYTE ZONE for collaboration with the local council and its community. VEGETATION BANDS Following this, potential locations such as currently polluted waterways were identified and projects tentatively proposed. The meetings also allowed Sydney OUTLET Water to establish a rapport and key contacts within council.

INFLOW 3. Undertaking desktop analysis of the potential options, proposing BYPASS and mapping out the locations and project sizes. Following field visits DEEP INLET MACROPHYTE of the proposed projects, Alluvium ZONE WITH ZONE OUTLET POND FRINGING INLET POND VEGETATION determined the catchment and Extended Detention Level potential treatment area, and Normal Water Level inlet pipe whether the proposed projects or channel 80% EMERGENT MACROPHYTE were feasible. Constraints such pipe or porous COVER outlet pipe rock wall connection as community sentiment, or concerns from council that WSUD Figure 3. A constructed wetland design example (Melbourne Water, 2010). stormwater management systems PROCESS AND Improvement Plan. Projects will may impede the current use of a involve WSUD to achieve the park for sport or recreation were OUTCOMES best possible water quality and also considered. Preliminary Sydney Water and Alluvium have liveability improvement for the costings were then established. developed project options for Parramatta River (McAuley, 2014). 4. Developing 10 project options the Parramatta River Waterway The process involved: to initial concept stage and

3 www.awa.asn.au Water e-Journal Online journal of the Australian Water Association technical paper River Health Photo: Noel Butcher A raingarden placed around a stormwater drain cleans stormwater runoff from the road and surrounds.

undertaking a cost, risk and This paper was presented at the 2016 benefit review. Alluvium used YWP Conference in Sydney. MUSIC (Model for Urban Stormwater Improvement The Author Photo: Noel Butcher Conceptualisation) modelling Thuwaarahan to estimate the proportion of Waren Nadesan Cunningham D (2015): Water Quality Program suspended solids, phosphorus (email: THUWAARAHAN. Business Case 2016 to 2020 Sydney: and nitrogen removed by each NADESAN@sydneywater. Sydney Water. proposed treatment. Alluvium then com.au) is currently in his reassessed costings based on any Cunningham D, Mcmanus R & Birtles P second year of Sydney Water’s (2015): Enabling Waterway Health and further risks, such as encountering graduate program. While completing Liveability in Sydney. 9th International contaminated soils, and benefits Water Sensitive Urban Design Conference his last year of university, Waren such as biodiversity and habitat, and 3rd International Erosion Control landscape amenity, community worked as a trainee with Sydney Conference. Dockside, Cockle Bay engagement and education. Water, where he planned the shutdown Wharf, Sydney, Australia.

and recommissioning of Sydney Water Mcauley A (2014): Water Quality Improvement CONCLUSION assets. In his first year of the program for Parramatta River. Sydney: Alluvium. With continued collaboration, Waren was Project Manager of the the Parramatta River Waterway Melbourne Water (2005) WSUD Engineering Parramatta River Waterway Procedures: Stormwater, CSIRO Publishing. Improvement Plan has the potential Improvement Plan. He also reviewed to create industry capacity, promote Melbourne Water (2010): Constructed development applications and similar works elsewhere and provide Wetlands Guidelines [Online]. Melbourne engaged and built rapport with a foundation of knowledge and Water. Available: www.clearwater.asn. data that will support the integration stakeholders such as councils, au/user-data/resource-files/constructed_ wetlands_guidelines.pdf [Accessed 20 of stormwater and wastewater community groups and customers December 2015]. management in the catchment to collaborate on joint projects. of Australia’s most iconic Melbourne Water (2015): Treatment Train waterway: Sydney Harbour. REFERENCES [Online]. Available: www.melbournewater. Brown R, Keath N & Wong T (2008): com.au/Planning-and-building/Stormwater- Transitioning to Water Sensitive Cities: management/Water-Sensitive-Urban- ACKNOWLEDGEMENTS Design/Pages/Treatment-train.aspx Historical, Current and Future Transition The Author would like to thank [Accessed 20 December 2015]. Phillip Birtles and Daniel Cunningham States. 11th International Conference on from Sydney Water, as well as Urban Drainage, 2008. Walsh CJ, Sharpe AK, Breen PF & Sonneman JA (2001): Effects Of Urbanization On Alexa McAuley and David Knights Clearwater (2012): Raingarden Design Streams Of The Melbourne Region, Victoria, from Alluvium for their guidance, Principles [Online]. Available: www.wsud. Australia. I. Benthic macroinvertebrate resources and years of knowledge and org/wp-content/uploads/2012/05/A3- communities. Freshwater Biology, 46, experience shared in writing this paper Raingarden-Quick-Reference-Guide_0.pdf pp 535–551. http://dx.doi.org/10.1046/ and in completing this project. [Accessed 20 December 2015]. j.1365-2427.2001.00690.x

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