Planning a Clever and Creative Water Future: Northern and Western Geelong Growth Areas Integrated Water Management Plan Aaron Dowling – E2Designlab
A Collaborative Approach to Planning a Water Future in Geelong Client
Consultant
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What does a city with IWM look like?
Greener
Healthier environments
Secure water supply
Cooler
Resilient
Liveable and effective places
Geelong - A city intimately connected with water High value waterways
Moorabool River
Barwon River
RAMSAR listed wetlands
Limeburners Lagoon
Lake Connewarre
Introduction to ‘NWGGA’ “The Northern and Western Geelong Growth Areas will have an exemplar integrated water management system with water as the enabler of clever and creative neighbourhoods that build regional resilience, while supporting local economies, healthier lifestyles and a thriving environment.”
• Over 5,300 ha of farm land rezoned for development • Future land use includes residential, commercial and industrial • Early in the planning process – Precinct Structure Plans still being developed • Batesford Quarry and Moorabool River a central feature of the Western GGA
IWM Plan Development
• What are the unique challenges and features?
• Water and pollutant balance • High-level assessment of long list of options
• Determine measures of success – what are • Identify options we trying to offering high achieve? benefits
• Concept design of selected IWM options • Combine complementary options into ‘portfolios’
• Multi Criteria Assessment • Economic Assessment • Recommended portfolio
• Action Plan • Adaptive Pathways Plan • Planning Implementation Framework
Key Drivers for IWM in the NWGGA Water supply
Growth and development
• 40,000 new homes • 110,000 new residents
Recreation and liveability • • • •
Canopy cover uplift On-site waterways Clever & Creative Corridors Batesford Quarry conversion to urban lake
• Supply catchments, borefields • System has capacity to 2035 • 6.6GL of new demand
Stormwater generation
• 350% increase stormwater • 400% increase pollutants • 9.5GL of excess stormwater
Wastewater generation • More than 5 GL per year
Receiving environments • Barwon & Moorabool rivers • RAMSAR sites downstream: • Limeburners Lagoon • Lake Coonewarra
Wastewater and Alternative Water Supply Blackrock Wastewater Treatment Plant: • treats most of Geelong’s sewerage to Class A recycled water which is supplied to Armstrong Creek and Torquay North developments. • located approx. 25km south of the NWGGA • existing sewer network has some spare capacity (~10,000 new homes) The Northern Treatment Plant: • recycles 2 billion litres of water per year for use at the Shell Oil Refinery • can produce more recycled water if needed • some potential to expand capacity • subject to ongoing use agreement with Shell A number of smaller scale water recovery plants are also in operation
Potable Water Supply Interlinked system of reservoirs to Geelong City drawing from three sources: - Barwon and Moorabool Catchment - Melbourne-Geelong Pipeline - Barwon Downs and Anglesea borefields Wurdi Boluc Stores approx. Geelong supply
2/3rd
of Greater
Demand is expected to increase by 50% for Greater Geelong to 2050* Existing allocations are likely to be sufficient to provide secure supply until at least 2035*
*Barwon Water Urban Water Strategy 2017
NWGGA
Wurdi Boluc Reservoir
Batesford Quarry Transformation
Batesford Quarry Today Moorabool River diversion c.1930’s
Moorabool River diversion c.1990’s
Quarry dewatering (~9 ML/day)
Moorabool River historical reach
Pumped outflows
Groundwater inflows
Batesford Quarry Urban Lake
Diversion repair to improve Moorabool flows
Batesford Quarry Section A-A 70 60 50 40
A
30 20
Pumped outflows to cease when quarry decommissioned
10 0 -10
~40m
-20 -30 -40 Quarry Existing Surface
Final Water Level (high)
Final Water Level (low)
Overflows feed historical reach restoration A Groundwater inflows
Physical Challenges:
• Water level • Water quality • Stop pumping and Moorabool flows drop • Risk of algal blooms • Seasonal variation threatens fringing vegetation • Stormwater runoff (phosphorus) a threat • Time to fill (approx. 19 years) • Salinity limits potential for reuse
Preliminary Assessment
Portfolio Composition Bundle
WW1
WW2
Portfolio 1
Portfolio 1a
Portfolio 2
Portfolio 2a
Portfolio 3
Portfolio 4
Forward-planned centralised systems
Forward-planned centralised systems
Flexible delivery of distributed systems
Flexible delivery of distributed systems
Investing in regional catalysts
Unlocking quick wins while planning for the futrure
1. Class A recycled water to dual pipe supply 2. Class A recycled water to local industry / horticulture
14. Wastewater for supplementary flows (Moorabool or Quarry)
WW3
5. On-lot greywater tanks 3. Class B recycled water for open space (ring main) 4. Class B recycled water to regional agriculture
WW4
SW1
10. Swales and enhanced infiltration areas
10. Swales and enhanced infiltration areas
SW2
12. Waterway corridor enhancement
12. Waterway corridor enhancement 6. On-lot rainwater tanks
SW3
6. On-lot rainwater tanks
Stormwater for open space
SW4
7.
SW5
9. Passively irrigated street trees
9. Passively irrigated street trees 8. Stormwater for indirect potable supply
SW6
11. Rainwater for
SW7
supplementary flows (Moorabool or Quarry)
GW1
WW5
8. Stormwater for indirect potable supply
13. Modified pump schedule for Quarry dewatering
13. Modified pump schedule for Quarry dewatering 15. Class A recycled water from NWP for open space (ring main) / industry
Detailed Assessment Dual Assessment Results: All Shortlisted Options
Scored Assessment: Portfolios
Adaptive Pathways Plan
Moorabool Rehabilitation and Naturalisation
Thank you aaron@e2designlab.com.au