Keen interest on biochar trial at Carters Creek

The Ashburton Water Zone Committee is supporting a trial using biochar to help improve water quality at Lake Hood.

The project, which will be coordinated by the Lake Hood Water Quality Taskforce and Ashburton District Council, will involve using biochar (a granular form of carbon) in Carters Creek, to see if phosphorus can be filtered from the water before it empties into Lake Hood.

High levels of phosphorus are thought to be contributing to an algal bloom in the lake, which has been under a Te Whatu Ora health warning from early January until May this year.

The zone committee recommended $10,483 to fund the trial, which involves laying mesh bags of biochar across the stream before it runs into the lake.

Project advisor Les McCracken said the creek was currently dry, but when it was flowing again, water would be tested weekly for phosphorus levels before and after passing through the biochar.

“There is a need for people to do practical things, real things and try to make changes.”

McCracken said there were other water bodies in the South Island facing similar problems and the results would be of wide interest. The trial is expected to last two months, depending on how flows go in the creek and the overall results.

The initial results of the trial will be shared with the zone committee later this year.