Unplanned discharges: Greater Wellington's role explained

A number of unplanned sewage discharges have happened across the Wellington Region recently, which has caused widespread concern among communities, as well as confusion about who is responsible for the region's stormwater networks.

Greater Wellington Regional Council Environment Committee Chair Penny Gaylor says it is important for the public to be aware of each organisation's role in dealing with sewage discharges that come through stormwater systems as a result of overflows to stormwater, cross connections (wastewater pipes being inappropriately connected into the stormwater network) or bust pipes.

"Greater Wellington is the regulatory authority on the stormwater systems throughout the region - which means it is our responsibility to regulate the quality of the water that comes out at the end of the pipes across the network."

"City and district councils hold the consents for the stormwater network, Wellington Water operates the networks on behalf of city and district councils, and then it is our job to ensure the quality of the water that comes out at the end is in compliance with the consents given," Cr Gaylor says.

Under those consents Wellington Water has a responsibility along with city and district councils to manage acute effects of discharges on human health - this includes putting signs and information out when water is not safe to swim in and also investigating and subsequently actioning any contamination issues with such effects.

"In terms of the ecological effects of sewage discharges, monitoring is carried out by Greater Wellington and Wellington Water under the Resource Management Act," Cr Gaylor says.

There are some ongoing investigations which will determine whether stormwater and wastewater consents have been adhered to. Once these investigations are completed the Greater Wellington will determine what, if any action to take.

"In terms of actions we can take as a regional council, this can range from a formal warning or education type response, to infringement notices or going as far as prosecuting for more serious breaches."

"The biggest issue region-wide is aging infrastructure which is likely to cost district and city councils millions of dollars to replace," Cr Gaylor says.

Council Chair Daran Ponter says "region-wide many councils face issues with aging pipe infrastructure which they would need to consider in setting their rates for 2020/21 and beyond."

"Greater Wellington does not comment on the specifics of ongoing investigations until all the facts have been established and a clear course of action has been decided."