A proposal to improve the quality of the water at Lake Te Koo Utu in Cambridge, New Zealand is underway.
According to Waipā District Council, the lake has poor water quality and there is now a plan to address this issue which would be broken down into three stages. The plan would include the construction of rain gardens and other measures to treat storm water runoff before it enters the lake.
Council water services manager Martin Mould said Cambridge residents have been vocal about improving the water quality of the lake, reported Waipā District Council.
“This is something that was considered extensively and addressed to a point in the draft concept plan,” said Mould, reported Waipā District Council. “For any significant improvement to the quality of the water however, we need to look at treating water before it goes into the lake. This is something we believe can be achieved through the use of rain gardens and proprietary devices.”
The proprietary devices would be fitted inside storm water pipes to filter water as it passes through. According to Mould, sources of contamination in the lake include: oil, petrol, zinc and rubber from cars.
“Once these pollutants reach the lake, they sediment at the bottom creating layers of contaminated sludge,” said Mould, reported Waipā District Council. “If we can ensure the water going into the lake is filtered of some of this, that should make a difference to its quality. While this isn’t a quick fix, it will help over time.”
The three stages would target the most critical areas first, including intersections. State two would treat high use roads and low use roads would be targeted in stage three, reported Waipā District Council.
Stage one includes the installation of 12 rain gardens which would be retrofitted near to high use intersections around the lake. Additionally, three proprietary devices would be fitted into the existing storm water outlets. In stage two, 32 rain gardens would then be installed, and 66 rain gardens would be installed in stage 3.
Stage one of the project will cost approximately $356,000 and is included in the draft Long Term Plan (LTP). Stages two and three will be considered in future LTPs, reported Waipā District Council.
