A fresh look at dual reticulation

June 2014

A fresh look at dual reticulation

An assessment of the performance and ongoing viability of dual reticulation schemes on the Gold Coast, the assessment utilises the Australian Water Recycling Centre of Excellence’s Total Economic Value Framework.

Irrigation Australia National Conference

Presented by: Kathy Baker Executive Coordinator Integrated Water Cycle Planning Gold Coast Water June 2014

Background

 Prior to 2006, GCW owned and operated its bulk water supply assets  Pimpama Coomera Waterfuture Master Plan (including Class A+ recycled water) adopted in 2004  By 2056, Class A+ predicted to contribute 20ML out of 366ML  Millennium drought effecting South East Qld  10 years since adoption – appropriate to review and consider the current and future costs and benefits Slide 3

Map… Slide 4

Map… Slide 5

Map…

Class A+ Uses:

 Outdoor – garden irrigation, car washing  Indoor - toilet flushing  Fire fighting Slide 6

Current situation

 Class A+ to 6000 properties in the Pimpama Coomera region  Use 0.5% (0.8 ML/day) City’s total water demand  10 ML/day is supplied by Class B/C recycled water schemes  Class A+ usage rate much less then expected  Only 8 ML/day expected in 50 years (2.4%) 350 300 250 200 150 100 50 0

8

Total Class A+ Recycled Water Demand Total City Potable Water Demand

0.8

152 Now 325 In 50 years

Slide 7

Key changes since adoption

Issues Assumptions/Outcomes

Drought Bulk water Population projections Environmental discharge Outdoor water use Household recycled water demand Millennium drought broke and water use behaviours have changed significantly in SEQ State Government took ownership Growth rates have slowed from those projected for the PIP. No Pimpama River release.

General outdoor water use has decreased by 65% compared with original assumptions.

Actual recycled water demand per household is currently 75% less than that assumed for original demand projections.

Scheme capital costs WOL (50yrs) capital costs for Class A+ recycled water, approx. double original estimate in the PCWF Master Plan. Scheme operating costs WOL O & M costs of Class A+ treatment & distribution system approx. 10 times greater than originally estimated.

Slide 8

Issues

 Cross-connections – complicated pipework on-lot and off-lot  Household audits Slide 9

Value and viability assessments

 Not financially viable - cancelled future expansion of DR into the Stapylton, Yatala and Cabbage Tree Point areas 

Detailed Value Assessment of Pimpama Coomera

 Total economic value of recycling – financial, environmental and social factors  Australian Water Recycling Centre of Excellence Slide 10

End of dual reticulation for City of Gold Coast

 Council resolved in December 2013 to discontinue implementation of dual reticulation on the Gold Coast due to:  High cost of operating and maintaining the scheme  High cost of constructing new capital infrastructure   Low demand usage Negative net “value” (costs outweigh benefits)  Significant regulatory monitoring and reporting requirements  Risk of cross connections  Estimated to

save

rate payers $3 million/year or

$114 million

over 40 years (in 2013 dollars) Slide 11

Transition Plan to decommission Class A+ supply

 Potable water to be supplied via both potable and recycled water networks  Initially operated as discreet systems (no mixing)  Class C return main from Pimpama STP to Coombabah STP  ‘Switch over’ estimated to occur by December 2016 Slide 12

Existing Recycled Water Scheme

60 50 40

Existing Recycled Water Scheme Recycled Water Reuse vs Rainfall

- Northern Supply Scheme 2500 - Southern Supply Scheme

Class B/C

2000 - Approximately 50 fixed customers 1500 Recycled Water Leaving WWTP 30 20 10 Rainfall (mm) Recycled Water Reuse Target - Total irrigated area approximately 1700ha 500 - Irrigation of Sporting Fields, Council owned Parks, Schools, 0 2000 2001 2001 2002 2002 2003 2003 2004 2004 2005 2007 2008

Financial Year

2009 2009 2010 2010 2011 2011 2012 Slide 13

Where to from here? Release

Seaway Ocean?

Local Opportunities

Identified further open space irrigation Additional treatment Class C to Class A+ - Jupiter’s Casino - Potential Commonwealth Games venues Slide 14

Where to from here? Potential Northern Recycled Water Scheme

Slide 15

PO Box 5042 Gold Coast MC QLD 9729

P

1300 GOLDCOAST

E

[email protected]

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cityofgoldcoast.com.au