Divers brought in to fix water supply pipeline from river
Specialist divers and equipment will be used to investigate an issue with a tunnel and pipeline from the Nymboida River which replenishes the main storage dam for our water supply.
As a result, Level 1 water restrictions are to remain in place until further notice.
The water quality issue is related to a tunnel and pipeline from the Nymboida River which replenishes the main storage dam for our water supply system at Shannon Creek.
Specialist divers and equipment are to be used to investigate the problem inside the tunnel and pipeline after flushing did not resolve the issue.
The Nymboida River catchment area was significantly impacted by the bushfires and subsequent heavy rains early in 2020, which washed debris from burnt areas of the catchment into the river.
It is believed that this unusually persistent dirty water issue is being caused by the amount of bushfire ash and silt which was deposited in the tunnel and pipeline by the heavy rains following the fires.
"The water in the Nymboida River is now clear, but water quality problems were experienced when starting to increase extraction to rates necessary to send water through the Regional Water Supply Scheme to Shannon Creek Dam and Karangi Dam," Coffs harbour City Council's Director Sustainable Infrastructure Mick Raby said.
As a result, Karangi Dam has been used to maintain our town water supply using water sourced from the Orara River.
But to continue the sustainable supply of water to residents, Level 1 restrictions need to stay in place until water can be safely extracted from the Nymboida River to bring the main storage dam - Shannon Creek - back up to full capacity.
"Quality and quantity of water are both important factors when looking to refill drinking water storage dams and as we cannot fill Shannon Creek Dam with dirty water from the Nymboida River, Level 1 water restrictions must remain until the water quality issue is resolved," added Mr Raby.
In addition, NSW Government licensing conditions only allow water extracted from the Nymboida River to be stored in Shannon Creek Dam.
Any water received directly into the dam from rainfall must be released to maintain the natural environment downstream.
Information on current dam storage capacity, restrictions and the Regional Water Supply Scheme is available from Council's website at www.coffsharbour.nsw.gov.au/water