Bathing water quality

Since 2013, Nelson City Council has invested $2 million into research, monitoring, infrastructure and community engagement to meet environmental water quality and river health targets.  We monitor water quality at key coastal and river swimming sites throughout the summer and the results are published on the LAWA Can I Swim Here module.

Currently, Council’s weekly water quality monitoring has given medium alerts at some localised spots. E.coli levels can vary throughout the day and are likely to be contributed to by current low river flows and by winds and choppy seas at coastal sites. Council is currently investigating the source of the E.coli which at this stage may be dogs or wildfowl. See the 2019-20 bathing water quality sampling schedule. (96KB PDF)

Toxic Algae Cyanobacteria

Toxic algae (also known as Cyanobacteria) is naturally present in many New Zealand waterways. It's found in ‘clean’ rivers but can grow when river flows are low and stable, and temperatures are consistently warm. Council routinely monitors its level and informs the community when action needs to be taken. Learn more in the Toxic Algae section.

Key results for recreational bathing water quality

Nelson’s beach monitoring sites at Tahunanui Beach and Cable Bay have retained Good recreation grades, with Nelson Haven (Atawhai) and Monaco (Wharf) attaining Fair grades. Occasional exceedences have been associated with rainfall events and high spring tides re-suspending washed up debris from the beach.

The Maitai River bathing holes between Maitai Camp and Girlies Hole continue to have Fair-Good grades, with few exceedances over the last five years.

The recreation grade for the Maitai River at Collingwood Street remains at Very Poor due to the risk of contamination from stormwater and other sources such as dogs and wildfowl.

The Wakapuaka River at Paremata Flats remains at Very Poor, due to contamination from sources including livestock, feral animals and wildfowl upstream of the sampling site.

The Fair grade was assigned to the Wakapuaka River at Hira Reserve due to the long term trend of elevated bacteria counts.

People are advised not to swim at sites with Poor grades, which are generally unsuitable for swimming, as indicated by historical water quality results.

Initiatives for improving recreational bathing water quality

Working with land owners

The Nelson City Council Land Management Adviser provides free advice for land owners and financial assistance towards fencing and native plants for riparian planting and biodiversity enhancement. Improving water quality in Nelson’s streams and rivers is a key focus. Further advice is also available on best practice land management and related issues, including maintenance of septic tanks. If you are interested in receiving advice please contact Lynne Hall, Environmental Programmes Officer 546 0308.

Nelson City Council work in progress

Council has launched Project Maitai/Mahitahi with the goal of improving the water quality of the Maitai River. A team including Cawthron scientists, Council and NELMAC staff is undertaking investigations to find the sources of bacteria in the Maitai River, including microbial source tracking to test for the presence of human faeces, dye testing waste water mains to identify leaks, and undertaking continuous bacteria sampling to understand the bacteria transport pathway in the lower Maitai River, Brook Stream and Saltwater Creek.

Annual Monitoring summaries