Addington Brook in Christchurch’s South Hagley Park is being naturalised to improve the biodiversity and health of the waterway, enhance the landscape and restore drainage capacity.
The spring-fed brook passes through heavy industrial land before winding its way through South Hagley Park and flowing into the Ōtākaro-Avon River near the Botanic Gardens.
Christchurch City Council is addressing the poor condition of the waterway, which it says has suffered from slumping banks, exposed tree roots and trees in inappropriate places, including within the brook itself.
“There have also been concerns about the safety of an open drainage channel with steep banks in an area with high pedestrian and cycle use,” Council said in a statement.
Work began in January on the naturalisation of the brook, encompassing the area north of the netball courts and past the cricket fields to Riccarton Avenue.
Naturalisation is the process of restoring drainage channels to a state like that found in nature, such as a natural creek, brook or river. Council says multiple criteria are considered including drainage, maintenance, ecology, recreation, safety, landscape, heritage and culture.
“The banks of the brook are being flattened and stabilised to reduce the risk of slumping, increase drainage capacity, and improve safety for pedestrians and cyclists.”
“In-stream features such as fallen tree trunks, fresh plains, interspersed rocks, riffles and pools will enhance ecological habitat.
“Native riparian strips will be added either side of the brook to protect against erosion, filter contaminants (improving water quality) and make it easier for park users to distinguish the waterway,” Council said.
Addington Brook shown in blue.
Combined with another future upstream stormwater filtration system, the project will improve the water quality and health of the Ōtakaro-Avon River, Council says.
Existing healthy trees will be retained and transplanted, and 250 new trees will be planted to allow for a range of tree species of various ages and heights. A mixture of plants along the banks of the brook and new trees will also improve shading and support the native bird population.
It’s expected the work will take around nine months to complete.
