FOLLOWING the successful installation of the retention basins earlier this year prior to COVID-19 lockdown, work is about to get underway in the Kawerau District for another flood protection project.
The COVID-19 lockdown has delayed the River Road Culvert Replacement project by several months and the Council’s operations and services team have been working hard to get it back on track since the district moved to Level 1.
A longer timeframe has been required to plan the works around existing infrastructure to ensure power cabling is not disrupted, which has now been completed.
The project entails replacing two culverts where the ‘overflow stream’ crosses under River Road. The downstream culvert is by Cobham Drive and the upstream one is at the entrance to the Council’s water pumphouse.
The work is needed because the existing culverts are multiple pipe structures and are too small in heavy rainfall events. After periods of heavy rain, the weed coming down the stream catches on the walls separating the culverts and restricts water flow.
This has causes significant flooding of homes around these areas in the past and has been identified by Council as an important flood mitigation project.
At the Cobham Drive site, the two small box culverts will be replaced with a larger 3.5m x 1.5m high culvert which will sit alongside the existing culvert barrel.
At the water treatment plant, the two 1200mm diameter pipe culverts will be replaced with a single 3.5m x 2m high box culvert. This provides three times more capacity.
The new culverts will be set slightly below the stream bed level to improve and provide for fish passage upstream and downstream.
The project will be completed one culvert at a time to provide for minimal disruption to residents in each of the areas.
The works will mean that the road over the stream will be closed during the works and will necessitate residents, school buses and kura kaupapa vans to travel the alternative route around the other end of River Road.
This will mean slightly longer travel times for residents and students, which the Council apologises for in advance.
Letters have been sent to residents regarding the project and likely disruptions to travel movements. In addition, communication has been made with Tūwharetoa, Ngāti Awa, Bay of Plenty Regional Council and Usabus. Council is also contacting Kawerau Schools.
Following a site karakia and blessing by Iwi, the site preparation works will start on Monday, October 12 at the downstream culvert adjacent to Cobham Drive. The road over this River Road culvert will be closed until January 10, with a break over the Christmas period when the road will be reopened.
Work on the upstream culvert will commence on January 11 and be completed by mid-March 2021.
Council wishes to thank residents for their support with these road closures and apologises for the inconvenience but is committed to reducing the flooding risk in these areas.
ABOVE: An aerial of the street plan showing the site of the two culverts that are being replaced along River Road.
ABOVE: Culverts at Cobham Drive that will soon be replaced. In heavy rain, weeds growing on the side of the bank and debris catch on the dividing wall and block the culvert pipes causing flooding to nearby homes and properties. Image supplied.