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R E P O R T |
TO |
WORKS COMMITTEE |
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FROM |
Russell Bond, Utilities Manager - Water Supply |
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FILE REF |
01.011.025 - OO192448.rtf |
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DATE |
6 May 2004 |
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SUBJECT |
UTILITIES REPORT WATER SUPPLIES |
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RECOMMENDATION That the report be received |
District Water
The Ministry for the Environment (MfE) are developing and implementing a national environmental standard under the Resource Management Act for human drinking water sources. This standard is to provide tools or guidelines on which to base decisions on sources of drinking water and for making comparisons between potential drinking water sources. The favoured option that the MfE are developing in consultation with council and health representatives requires the monitoring, grading and reporting of the quality of human drinking water sources. The standard is proposed to apply to communities with more than 500 people.
RECOMMENDATION
That at the Technical Workshops scheduled for May 2004 a submission be made to modify the Water Quality categories in Table 1 to reflect treatment requirements rather than the present qualitative and descriptive terms.
New Zealand Water & Waste Association and the Water Supply Managers Group have developed an information booklet, The Story of Drinking Water. Copies of the booklet are circulated. The booklet describes the water cycle and discusses availability, properties, treatment, uses and costs of drinking water. It targets the student/general public audience with water conservation in mind.
RECOMMENDATION
That class sets of The Drinking Story be made available to each of the District’s Schools.
Plains WaterPreliminary investigations into the use of off stream storage for the Waitakaruru Water Treatment Plant has shown the dam and plains reservoir options to be moderate to high cost and associated with moderate to high risk. Options utilizing Tetley’s Quarry have the lowest development cost and are lower risk.
The analysed cost of the Tetley’s Quarry option does not take into account the value of the good quality rock which would have to be left in place to separate the operating quarry from the water storage.
Deep groundwater bores were also considered as a supplementary water supply. Although development cost is low there is a high risk that the quality of water from the bores could require a high level of treatment for drinking water purposes.
Pattle Delamore Partners are currently reviewing the data and reports associated with the Waihou River quality, backwash trial data and drain hydraulic information. Current investigations into existing piping available for disposal to the Tanner ponds indicate that both the whey pipeline to the ponds and the 600mm concrete storm water pipe that runs past the ponds are in good usable condition. This is favourable to the pond disposal option in the event that disposal to the Waihou River via the land drain is not found to be feasible.
A brief is being formulated by which Maunsell consultants will carry out investigations to address concerns expressed by Environment Waikato about operation of the Cut as a raw water reservoir. These concerns include the effect that raising the downstream stop bank (to reduce salt water ingress) would have on the flood protection of the surrounding area. They also include the possibility of increased shore line erosion from wave action arising from the rise and fall of the water level, and how the effect on the activities of local users of the Cut for water sport practice can be minimised.
Waihi WaterOpus Consultants are using the water quality and river flow data that has been collected over this summer to evaluate the currently proposed sources of supply, related storage capacity requirements and storage installation possibilities. The policy of the Regional Council limits stream draw off to 10% of Q5 and creates the need for storage, as adherence to the draw-off limitation will deliver only about 12% of the daily water requirement by direct abstraction in the dry summer months.
Russell Bond
Utilities Manager - Water Supply