Council Minutes - Town of Cambridge

COUNCIL MINUTES
TUESDAY 20 DECEMBER 2011
Of greatest concern is that regulatory approval for the project will need firm data confirming
water quality of the stormwater is better than the aquifer. If this is not proven then water
treatment (at significant costs) will be necessary. Sampling to date is not sufficiently robust to
make the risk free assumption that the HMD water quality can be left untreated prior to
infiltration to the aquifer. A significant cost risk is thus left unanswered.
The second main issue is that further hydro geological analysis is necessary to properly model
the ground conditions to ensure sufficient understanding is made of water infiltration and
impacts on Water Corporation's drain asset and Wembley Golf Course ground water.
The risk assessment leads to the conclusion that there is insufficient certainty at this stage to
identify the likely capital and operating budgets for the project.
Grant Funding
The Commonwealth Government recently closed submissions for Round 3 funding of
Stormwater Harvesting and Reuse grants. The Town may have been in a position to submit an
application for partial funding (up to 50%) of this project however with the degree of uncertainty
regarding costs and no Council decision to proceed; it was decided not to submit an
application.
If a decision is made to continue with this project, funding sources will be explored.
Perry Lakes
The consultant also provided some advice as to the feasibility of harvesting stormwater from
HMD and diverting it to Perry Lakes. The initial advice is that the system would need to pump
water from the drain, into new pressure pipes and into the lakes. The capital cost would be in
the order of $4.5 million with significant operating costs for electricity to run the pumping
process. This issue has not been pursued further.
Necessary Works to Reduce Risks
If a decision was made to continue with this project, the following actions need to be
undertaken to better quantify the project capital, operating costs and general risk:
Measure water quality in both the local aquifer and HMD over the same time frame for a
nominal 12 month period
Measure water flow in HMD over a nominal 12 month period to confirm data that is 10
years old
Undertake assessment of vegetation and environmental impacts of the infiltration basin
Complete hydro geological modelling to greater degree of certainty
Review budgets based on the outcomes of investigations
It is estimated that the costs of these investigative works would be in the order of $150,000.
Why should Town of Cambridge Invest in this Project?
Irrigation Supply
Currently, there is no charge levied for bore water licensed to the Town for irrigation. The Town
has a licence for irrigation suffice for current needs (assuming the Town continues its program
of water friendly plantings). If, in a drying climate, circumstances change and the State
implements significant restrictions to irrigation supply, this project may present itself as a better
financial outcome for the Town to continue irrigation of its golf course, parks and gardens.
H:\CEO\GOV\COUNCIL MINUTES\11 MINUTES\DECEMBER 2011\C CR.DOCX 197