Biochar to be Used to Filter Phosphorous in New Zealand’s Lake Hood

May 2, 2024 | 0 comments

The Ashburton Water Zone Committee has recommended that Environment Canterbury agree to fund a biochar trial 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 since early January.

The zone committee recommended ECan grant $10,483 to fund the trial, which involves laying mesh bags of biochar (a granular form of carbon) across the stream before it runs into the lake. The application was made by the Ashburton Aquatic Park Charitable Trust, which is working with the Lake Hood Water Quality Taskforce and Council on potential solutions to the cyanobacteria problem. The funding will be released to the Trust once it has been formally approved by Environment Canterbury.

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

Continue reading at Ashburton District Council