Council is working on stabilising reservoir levels
Buller District Council shut down the Westport and Carters Beach water supply today from 9am – 3pm to repair leaks in the water trunkmain to town. This is part of a concerted effort to prevent further water losses from the water reservoir.
Manager infrastructure delivery Eric de Boer says: “Currently the water reservoir is at 46.8% with Westport and Carters Beach using 5,200 cubic metres of water each day. With no water going in, this would supply the town with water for 6 days.
There is a major leak on the trunk main that our contractors will fix during the shutdown. Plugging this leak will result in reasonable conservation of water which will help considerably to slow down the depletion of water in the reservoir.”
Yesterday Council put in place an essential use water restriction order for the Westport and Carters Beach water supply. Essential use means water can be used for drinking, food preparation, hygiene, and sanitary purposes only. There is a complete ban on any outdoor water use.
Mr de Boer says: “We had a few small wins yesterday that mean we could pump and add water into the water reservoir.”
Contractors re-established yesterday one of the initial settling ponds that were washed out by the rain. This water could be pumped into the intake that feeds the intake for the reservoir ponds which in turn supplies the water treatment plant. Staff are working on establishing another settling pond to pump water from. Pipes were put in place to channel clean water from some the clear side creeks into the intake.
Mr de Boer says:” Our contractors and staff have worked on finding ways to find additional water sources to feed into the water treatment plant which will bring our water reservoir levels up. Combined with fixing the leak on the main trunk main, resident’s efforts to keep their water use to a minimum, they are making a difference and will help us to keep reservoir levels stable and ultimately bring them back up.”
Currently contractors are pumping an average of 52 litre per second from a small side stream into the water intake for the water treatment plant. Establishing the secondary pipes and settling area will add approximately another 25 litre per second which will result in a total flow of 76 litre per second meaning the reservoir is going to be gaining water.
Mr de Boer says;” We are expecting to be able to at least hold reservoirs with a 5-day spell of clear weather coming through.”
Essential use order will remain in place until storage levels have sufficiently recovered back up to 60%. Once this is reached the essential use order will be downscaled to restricted use to bring the water supply back to 80%.
“We are working hard on managing the situation and know that our water infrastructure is inherently fragile since the February 2022 weather event, but right now our primary focus is the supply of safe drinking water to the community. If we all pitch in, we will be able to maintain our supply.”
Background:
The Westport water supply is sourced from Giles Creek in the hills to the southwest of the town at the base of Mt Rochfort.
During the February 2022 rain events, there were significant slips within the catchment which resulted in the water becoming too turbid (dirty) to treat. In the last 30 days, the Westport catchment has received 515 mm of rain which has resulted in further slips in the intake. This has meant the catchment water has become too dirty to treat.
The water treatment plant generally requires water that is under 5 NTU (turbidity units) and due to these recent slips, the water from the creek has been 15 NTU at the lowest. As a result, Council has been unable to extract water from the intake.
There are several branches of the intake which have varying levels of turbidity. Council currently has set up a pumping system to allow for clean water to be abstracted, however the quantity available from this stream is insufficient to meet demand.
-ENDS-
further information please contact:
Manager Infrastructure Delivery
Eric de Boer
eric.deboer@bdc.govt.nz