Halswell Drainage Scheme moves forward

Schaeffers Drain, Court Rd, Tai Tapu – well positioned plants, high up on the bank, shade the drain to reduce weed growth.

Schaeffers Drain, Court Rd, Tai Tapu – well positioned plants, high up on the bank, shade the drain to reduce weed growth.

 

Around twenty-five kilometres of drains have been re-battered within the Halswell Catchment and Whakaora Te Waihora engineering workstream leader, Dan Harrison is confident the team will meet its goal of re-contouring 40km of drains by the end of 2015.

The project is focused on upgrading drains and waterways within the Halswell Catchment to facilitate planting on banks, which will shade water and reduce weed growth, which in turn reduces the amount of work required in keeping waterways clear.

“This helps hold the banks together to lessen erosion and lessen the amount of sediment in water. Making the water cooler also benefits in-stream ecology,” says Dan.

“The project is about improving the environment at the same time as improving drainage and reducing drainage maintenance costs. This in turn will hopefully reduce the amount of disturbance in drains, leading to less sediment going into the lake and creating a healthy habitat for birds, fish and other wildlife.”

Dan says the main challenge of the drainage programme is finding both willing landowners who will agree to this work being done on their land, and areas where there is enough space to carry out re-battering work. Weather restrictions are also a key factor that can affect the work timetable.

Preparation work prior to planting, Quaifes Rd Drain, Halswell.

Preparation work prior to planting, Quaifes Rd Drain, Halswell.

Re-contoured and planted drains need to be fenced if there are stock on the property. This can take up a bit of space, making some landowners reluctant. However, as well as improving the aesthetics and stock health on a property, fenced and planted waterways add value to a property as well as the wider environment. Improved drainage can also make farmland more productive.

Planting the newly re-battered drain banks is a priority too. To that end, Dan and his team work closely with Whakaora Te Waihora Planting Programme Leader Andy Spanton, who creates the planting plans for the drain bank areas.

“It’s important that we plant the right plants in the right places,” says Dan.

“We have to ensure that plants don’t grow into or over the drains, or they can cause flow and sediment problems.”

Anyone interested in improved drain management on their property should contact Dan at Daniel.harrison@ecan.govt.nz or Andy Spanton at Andrew.Spanton@ngaitahu.iwi.nz.