Wednesday 13 September, 2023
A crack has formed at the top of a section of the wastewater pipe located at the Adventure Playground. This section will be replaced, weather-dependent, at the end of this month.
During the repair, a portion of Midway Beach known as ‘The Pipe’ will be closed.
Council’s Water Manager Leo Kelso says the pipe repair needs to be done soon.
“The damage is undermining the pipe’s capacity to transfer wastewater – especially during a heavy rain event.
“The impacts of Cyclone Gabrielle and unrelenting rain for the first half of this year has put consistent pressure on this pipe resulting in the damage.”
Mr Kelso says the pipe is still operational, however usually the sewer overflow valves are opened into our rivers when flows are six times higher than our normal dry weather wastewater flows.
“This crack means if we have a medium-heavy rain event, the sewer valves would need to be opened at 2.5 times higher than normal flows.”
Mr Kelso says the plan for the pipe replacement is to start late on Wednesday 27September and be completed by Thursday 28 September.
“The team will work through the night when wastewater flows are at their lowest. Beach access will be closed in this area during this period.
“Working through the night will minimise the time the beach needs to be closed and any impact on our residents.
“It’s not a huge job as the portion of pipe that needs to be replaced is only around eight metres long. However, its proximity to the shoreline, the influence of tides on ground water levels, and the critical function the pipe performs make the replacement more complicated.
“It will take around 24 hours for the pipe replacement as we need to work through up to three low tide cycles, and wastewater will be re-routed during the repair.
“Our team have explored all possible options to avoid having to discharge wastewater to our coastal environment. However, unfortunately this is the only way that we can repair the pipe.
“The wastewater will be released into the sea on Midway Beach and this area of the beach will be closed to the public while this happens.”
Mr Kelso says the wastewater is treated to a high level as the new Wastewater Treatment Plant upgrade ensures all residential wastewater will pass through the biological trickle filter, be clarified, filtered, and UV treated before it is discharged.”
“This area of beach will be signposted clearly over the period of closure.
“The repair is close to the surfing spot known as the Pipe, which is why it’s important the community is aware in advance of this happening.”
Mr Kelso says large concrete blocks will need to be set up in the shore break at Midway, in line with the pipe repair location, on Monday 25 September to support the pipes for the shore release.
“The transfer pipes will be set up on 25 and 26 September. The concrete blocks will be marked with large floating buoys to ensure they are visible and beach signage will mark their location.
“This section of the water will be closed while the pipes and supports are in place to ensure public safety. The pipes and concrete supports will be removed on the low tide following the pipe replacement. Access along the sand will be opened following the pipe replacement.
“We have met with hapū and the medical officer of health.
“The advice is that the water should not be swum in, or shellfish gathered, for a minimum of five days after this event.
“This date range will be signposted along the beach.”
Mr Kelso says this repair has to be done in dry weather, so if the weather is not suitable on 27 September it will be done in the next suitable weather window including a daytime operation.