Caring for the environment  |  5 Jun 2019

A resource consent that aims to future-proof Christchurch's stormwater network while also improving water quality in certain rivers has been granted by independent commissioners appointed by Environment Canterbury.

The Christchurch City Council applied for a comprehensive consent to discharge stormwater from the existing and future reticulated stormwater network within Christchurch City and the settlements of Banks Peninsula.

Stormwater, which is any water that falls on roads, paths and other hard surfaces, picks up pollution and flows untreated via drains into local waterways. If the discharge is untreated, this affects the health and water quality of local streams and rivers.

The resource consent means it will be the first time that all stormwater discharges from the reticulated stormwater networks in Christchurch City and Banks Peninsula will be managed under one resource consent, with a Stormwater Management Plan developed for each of the seven sub-catchments.

The seven sub-catchments are: Outer Christchurch; Pūharakekenui/Styx River, Ōtākaro/Avon River, Ihutai/Avon-Heathcote Estuary and Coastal areas, Huritīni/Halswell River, Ōpāwaho/Heathcote River, and Te Pātaka o Rākaihautū/Banks Peninsula.

The City Council will develop the management plans with input from the community and relevant stakeholders.

In the decision today, the 25-year resource consent affirms the conditions that the City Council proposed which require a reduction in contaminant loads in the discharges to improve the water quality in the receiving rivers as well as protecting the city’s groundwater resources.

The commissioners noted that “there appears to be (a) strong and collaborative relationship between the applicant and Canterbury Regional Council aimed at collectively improving water quality”.

Environment Canterbury chief operating officer Nadeine Dommisse said: “It's vital that we have these plans in place to ensure that our city's stormwater doesn't negatively affect our rivers.”

She said it had been a long process to get to this point as the consent was very comprehensive.

Christchurch City Council General Manager City Services David Adamson said: “We welcome the hearing panel's decision around the resource consent, which represents a significant amount of work and engagement between agencies and the community over the past five years. We will now take some time to carefully consider the decision document and any responses to it.”