20110627 wsud in planning final .ppt - city of knox · bioswales, trenches, etc. • miminise hard...
TRANSCRIPT
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
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
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
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
• 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.....