Goulburn Water Group - their plan ...

A diagram of the Goulburn Water Group plan / Image by Neil Penning

The Goulburn Water Group plan:

1. Stormwater or surface water use: where water quality from city runoff is improved so that the rivers are not adversely impacted, and expanded to get some quantifiable yield credit.

2. Demand management: conserving our water use to 250 litres per day per person, a 30 percent reduction from previous use. Businesses could also permanently reduce their use by 30 percent, the current water restriction target. The Goulburn Water Group suggests the arrangement could be linked to water licences and storage provisions so that there is room for population growth.

3. Improvements to Mulwaree River water quality: Goulburn-Mulwaree Council plans to build a 100ML wetland and divert the river on the low side of the city. The group suggests city runoff, which comprises 65 percent of our stormwater, be diverted through the wetland, and that water be gauged out of that system to be credited to Goulburn as higher environmental flows.

4. Rossi Weir augmentation: GWG suggests the weir be strengthened and raised so its capacity is increased, as well as its pumping capacity back to Sooley Dam. The group suggests 200ML be put back into Sooley from the Weir each day - currently 50ML is pumped into Sooley from Rossi, when the weir is flooded - and the abolition of the 65 percent backfilling limit for Sooley.

5. Evaporation control on Sooley Dam: GWG says more detailed exploration of evaporation control measures on Sooley Dam are worth consideration. The group says that even if that does not work out to be feasible, council could still calculate the minimum evaporation to water height ratio and maintain that level.

6. Build a Heffernans Creek weir: GWG says a weir at this location would help to harvest more stormwater. The group says the weir could be normally open, but closable when the river was in flood so that the water could be trapped and pumped via a pipeline back to Pejar Dam. The pipeline could be two-way, so that water is transferred back to Goulburn for its own use. The group has costed the weir to be about $3 million to build, and the pipeline $9 million.

7. Use of recycled water from treatment plant: The GWG plan calls for recycled water from the Goulburn sewage treatment plant to be used for unlimited reuse by industry and residents for parks, gardens and irrigation. It would also augment environmental flows in the Wollondilly River upstream of the city.

The group says the Copford Reach pipeline could recycle water from the plant and put it back at the top of the Marsden Weir. Recycled water could also be piped back parallel with the Mulwaree River to fields and the Goulburn Golf Course, with standpipes along the way releasing the recycled water for businesses and construction projects. The group says Tully Park, Goulburn Gaol and the Police Academy could also draw from the recycled water, with these initiatives offsetting "significant amounts" of drinking water that was previously used in these places.

8. Rainwater tanks: The group says that if half of the 7000 properties in Goulburn were supplied and fitted with 10,000 litre rainwater tanks, it would produce about 263ML of water per year for the city, based on a calculation of 150 square metres of roof area and 500 mm of rain. Each tank would cost about $5000 to fit and supply.

9. A new southern sewage treatment and water polishing plant: The group says a second plant should be built on the southern side of the city to service a capacity of 10,000 people. The northern sewage treatment plant has a capability for 24,000.


See - Goulburn Water Group plan.