Kiripara Stream draining freely after being cleared.
Kiripara Stream draining freely after being cleared.
Stormwater maintenance on the drainage systems of Watts St and Shanly St in Waipawa has made a significant improvement to two areas of identified flooding risk, says Central Hawke’s Bay District Council.
Council contractors have been excavating and removing vegetation to provide resilience and community confidence in the areas of lower Waipawa, which were inundated during Cyclone Gabrielle in 2023.
“The downpours at the end of June were an opportunity to see how the increased open drain maintenance affected the performance of the network,” CHBDC chief executive Doug Tate says.
After Cyclone Gabrielle, stormwater funding was reprioritised and urgent maintenance work was completed, including many sites that had not been maintained for at least 20 years.
Based on priority, the council has now excavated four kilometres of drains (25% of the network), cleared vegetation on 5.5km (31% of the network) and completed 2km of pipe flushing (5% of the network).
Bush Stream, lower Waipawa, before clearance work.
Landowners who had major blockages on or next to their land were contacted and the blockages removed. This clearing work is continuing throughout Waipawa to two kilometres downstream.
The council’s Three-Year Plan for 2024-27 has nearly doubled the level of investment in stormwater, the first year being funded externally and years two and three by rates. This funding will address structural works that are required to remove blockages in the network, such as McGreevy St.
Bush Stream, lower Waipawa, after clearance work.
The funding will also bring a new and higher level of service, including inspecting the entire open drain network annually, as well as targeted inspections before rain events, two-yearly vegetation clearance on major open drain channels, five-yearly bed excavation to remove vegetation overgrowth and sedimentation and 10% of the piped stormwater network flushed or inspected each year.
An overarching strategy will be developed for how stormwater activity is managed in the future, including the development of a hydraulic model for Takapau and updates to Waipukurau, Waipawa and Otāne models.
Kiripara Stream before it was cleared.
The council reminds landowners that Waipawa’s stormwater networks are primarily drains on private land that connect to the council’s stormwater network, and that residents have a part to play in keeping stormwater and drains cleared and operating.
“Please report issues and identify problem areas, but most importantly keep drains clear of rubbish, green waste or anything that could restrict the flow of water,” Tate says. “Blockages stop the flow of water through the drainage network and increase the risk of flooding. Blocked drains can be caused by stock fencing in or across drains as they can catch debris and any plants, fallen branches or green waste.
Kiripara Stream after the clearance work.
“If the council is informed of issues with private drains, we work with landowners to find the best solution to benefit the whole network.”
The council will be undertaking critical works where blockages exist and will keep the community advised about the timing of these works, as well as the implementation of the new maintenance programme and the development of a stormwater model strategy.
