Water Sensitive Urban Designin the Planning Process

WSUDWSUD

Elke LindnerWhitehall Terrace - Ferntree Gully

WSUD Topics

• Why do we need to consider it?• WSUD methods• WSUD methods• Council Statutory Planning requirements• Assessment tools

• Stormwater pollution – the biggest threat to our urban rivers, creeks and bays

Why consider it?

to our urban rivers, creeks and bays

• 500 billion litres/year of polluted water released via stormwater drains

• Excess nutrients cause vigorous algae growth threatening animals & plantsgrowth threatening animals & plants

• Litter is washed into the bay, out to sea threatening animals and humans

Why consider it?

Sea turtle stomach

Albatross stomach

Why consider it?

Citarum waterway -Indonesia

Stormwater pollution becomes a bigger challenge the more Melbourne grows.

A Challenge?

challenge the more Melbourne grows.• Higher urban density

o More roads, concrete, roofs and paving where a natural environment used to be.

o Reduced permeable areas

• More severe weather events (Parliament of Australia

http://www.aph.gov.au/library/pubs/climatechange/theclimate/moreextreme.htm)

• Flash-flooding • March 2011 - 26 millimetres of rain in Melbourne in less an hour

Latest Rainfall Events

Clockwise from left: South Melbourne; Chapel St; North Melbourne

The Opportunity:Water Sensitive Urban Design

(WSUD)• Reducing Peak Flows• Reducing Peak Flows• Removing Litter and

Pollutants• Add value & minimise

drainage costs• Protecting Natural Systems• Protecting Natural Systems• Return on Investment:

� Reduced utility costs� Combat water rate increases� Alternate source during

disruptions

WSUD Methods

• Primary Treatmento Gross Pollutant Traps

• Tertiaryo Raingardenso Gross Pollutant Traps

o Filtration

• Secondaryo Grassed Swaleso Buffer stripso Infiltration

o Raingardenso Bioswaleso Wetlandso Detention

Basins

• Diversiono Infiltrationo Green Roofs

• Diversiono Water Tanks

• Captures and filters water through a

Bioretention

water through a biological or porous medium to remove nutrients and other pollutants

• Raingardens, • Raingardens, bioswales, trenches, etc.

• Miminise hard surface area• Concrete pavers, ashphalt• High pressure hose to clean

Porous Paving

• High pressure hose to clean• Cost similar or less than

traditional pavement

Sydney Olympic Park

Raingardens• Diverse install methods suitable for all

developments• Size approx. 2-5% of treatment area• Size approx. 2-5% of treatment area• Treat directly from downpipes, paved

areas, driveways etc.

Above GroundIn-Ground

RaingardensConstruction – Cross Section

Raingardens

Pathway, road & car-park treatment

Arboretum Carpark - Dorset Rd, Ferntree Gully

Raingardens

Knox Council Civic Centre - Burwood Highway, Wantirna South

Swales & BioSwales

• A channel conveying water from one point to another.

• Facilitates infiltration into • Facilitates infiltration into soil.

• Removes pollutants & sediment.

• Reuseo Toilet flushing

Water Tanks

o Toilet flushingo Irrigationo Car washingo Cooling towers

• Detentiono Minimises

additional additional detention infrastructure requirement

Wetlands and buffer zones

• drainage system directs all roof water into the wetland in the forecourt

NAB Head Office – Docklands, VIC

Statutory Planning Requirements

• Knox City Council Municipal Strategic Statement (MSS) – Objective 6:– Objective 6:o Reduce the impact of urban stormwater run-off on creeks, rivers, bays and

other receiving waters and their surrounds, both within and outside the City.

o Ensure new development contributes to the ongoing improvement of stormwater management and the quality of stormwater runoff, and reduces pollution in local waterways.

o Ensure all new developments and redevelopments minimise the amount of impervious surfaces on a site.

o (plus additional...)

• Victoria Planning Provision - Clause 56.07o states that urban stormwater management systems for all new (greenfield)

residential subdivisions are to be designed and managed to meet the current Best Practice Environmental Management (BPEM) objectives..

o (plus additional...)

• Knox - Sustainable Design in the Planning Processo Residential: 3+ Dwellings

Statutory Planning Requirements

o Residential: 3+ Dwellingso Industrial/Commercial: 500m2+ Gross Floor Area

• Required to achieve Urban Stormwater Best Practice Environmental Management targets (BPEM)

o 80% retention of Suspended Solids (TSS) o 45% retention of Phosphorus (TP)

45% retention of Nitrogen (TN)o 45% retention of Nitrogen (TN)o 70% reduction of litter

> Corresponding to a score of 100% in Melbourne Water’s online STORM tool

*BPEM targets aim to achieve objectives of the State Environment Protection Policy (SEPP) – Waters of Victoria statutory policy under section 16 of the Environment Protection Act (1970)

(Stormwater Treatment Objective - Relative Measure)

WSUD Assessment Tool -STORM

• Developed by Melbourne Water• Residential & Industrial/Commercial sites up to 1 hectare• Quantifies WSUD treatment measures into a percentage when

compared to best practice environmental management targets

• Treatment Typeso Rainwater tank o Rain gardens

WSUD Assessment Tool -STORM

• To improve score:o Increase rainwater tank size

(& roof area draining to tank).o Rain gardenso Swales o Pondso Wetlandso Infiltration systemso Buffers

(& roof area draining to tank).o Install Raingardens to treat

downpipe flow or carpark/driveway runoff.

o Minimise total hard surface area by using permeable paving for driveways.

• Assumptions- STORM assumes rainwater tanks are connected to toilets for sanitary flushing.

WSUD Assessment Tool -MUSIC

MUSIC (Model for Stormwater Improvement Conceptualisation)

• A conceptual design tool – for large or complex • A conceptual design tool – for large or complex developments.

• Demonstrate performance of stormwater quality improvement systems.

• Proprietary Software by eWater CRC.(www.ewater.com.au)

- Approx $1,000 single PC license- Training available through Monash University & eWater- Training available through Monash University & eWater

• Impervious Areas• Proposed treatment

STORM - Example

Residential

• Proposed treatment methods

ie.• Roof to tank: 250m2

• Untreated roof: 50m2

• Drive to raingarden: 100m2

• Remaining untreated: 50m2

Assessment Tools – STORMPractical Example

• Need to enter details of all impervious (hard) surfaces in the

http://storm.melbournewater.com.au/

• Need to enter details of all impervious (hard) surfaces in the development and the corresponding WSUD treatment type for each

• Important to include all untreated surfaces for an accurate score

• Enter details of all impervious (hard) surfaces in the development and the corresponding WSUD treatment type for each:

Assessment Tools - STORM

• Aiming for a score of 100% - representing Best Practice Performance

Assessment Tools - STORM

Submit

Return to calculations if required

Submit report to Council

Assessment Tools - STORMExample – Industrial

• Hardstand to 50m2 raingarden (300mm deep): 1,000m2

• Untreated hardstand: 150m2

• Site Area: 4,000m2

• # Occupants: 40• Roof draining to 50kL tanks: 1500m2

• Untreated roof: 500m2• Untreated roof: 500m

Council Recommendations

Consider WSUD early in the planning phase:

• Identify land use capabilities of the site

• Include WSUD treatment features in first round design • Include WSUD treatment features in first round design documentation to expedite permit approval process.

• Integrate WSUD into landscape & civil drainage design.

• Provide a STORM assessment with a Planning Application

Key Messages

WSUD improves waterway health,

&

reduces overall size & cost of drainage infrastructure.

&Consider WSUD early in the planning phase & submit STORM

report

• Will the price of water have an impact on the price of beerN??

AndN

the price of beerN??

Thank you

References• www.knox.vic.gov.au• www.storm.melbournewater.com.au• www.raingardens.melbournewater.com.au• www.publish.csiro.au• www.epa.vic.gov.au/water/stormwater

info@organicaeng.com.au

• www.epa.vic.gov.au/water/stormwater

(appendix A)

Buildings: Stormwater Pollutants

• Gross Pollutants - litter- building materials- building materials- organic material, etc.

• Excess Nutrients - Nitrogen (N)- Phosphorus (P)

• Total Suspended Solids (TSS)

• Oils and Grease• Oils and Grease

• Other Hydrocarbons and Chemicals

• Heavy Metals, pH imbalance, Salinity, etc.....