13 September 2017
Cobden flood protection given green light
At yesterday afternoon’s joint Greymouth Floodwall Committee meeting the committee endorsed the proposals to proceed with the following work to reduce flooding in the lower Cobden area.
Works will include:
- Improvements to the culvert floodgate to allow easier and more effective operation of the flood gate to address flooding overflow from Range Creek when the Grey River is in flood
- Installation of a telemetered water level recorder downstream of the gate to assist with providing more information to operations staff
- Upgrade of the culvert to a one way valve to allow for water to drain while preventing any backflow
Construction of a 100 metre bund around the western end of Nelson Quay to minimise the impact of inundation from elevated lagoon levels
- Blocking of the ditch mouth to prevent any backflow of water from Range Creek.
Andrew Robb, Chairman of the West Coast Regional Council said that flooding occurs in this area due to a number of different factors.
“Overflow from Range Creek, storm water from overland flow, backflow through storm drains, and an increased water level in the Cobden Lagoon from spring tides and storm surge all have an effect. There is no one solution that will fix all of these problems, so we are looking at a combination of actions to reduce flooding in this area.”
Staff from the West Coast Regional Council and Grey District Council have been working closely with NIWA to identify a range of options to get the best outcomes for those affected.
"We will be undertaking the majority of these improvement works over the next 3-4 months,” said Mr Robb. “While we do not expect that this will completely resolve all flooding issues in this area, we do anticipate it will significantly reduce the extent of inundation.”The Greymouth Floodwall Committee comprising elected members from West Coast Regional and Grey District Councils will meet again in February 2018 to review the effectiveness of these works and discuss potential further protection to properties in this area.
Randal Beal | Operations Manager | West Coast Regional Council | 021 702 591