Water and sanitary services assessment 2005

Adopted 18 August 2005

Nelson City Council produced a Water and Sanitary Services Assessment (WSSA). All the water supplies, wastewater and stormwater systems, public toilets, wastewater dump stations, cemeteries and crematoria have been assessed.

The exercise also included an opportunity for the public and special interest groups to influence how and what water and sanitary services are provided in Nelson City in the future. Getting a good idea of public opinion is vital to being able to produce a final assessment which reflects the demand and best options for future development.

The assessment includes Council and privately owned services. The aim is to assess the adequacy of these services, both now and for the future. It looks at the risks that the services, or lack of them, may pose to public health and well being, the community and the environment.

With this overview of the water and sanitary services, Council can plan and prioritise improved service levels and consider its obligations as a Unitary Authority. This is the first time that Council has looked at all the services in the area, not just the ones they own. It is an opportunity to see how the services are provided and to identify any issues with inadequate services, or lack of services altogether.

The assessment includes services supplying communities of more than 25 people for more than 60 days per year but excludes water or sanitary services supplying individual or smaller groups of rural properties. 

Water Supply Assessment

The Nelson City territorial area is served by several water systems:

  • The Nelson City reticulated supply takes water from the Maitai and Roding Rivers and treats it at the Tantragee Saddle ultrafiltration treatment plant. This serves most of Nelson City.
  • The Tasman District Council reticulated supply takes water from the Waimea Aquifer serving properties, mostly industrial, south and west of Saxton Field.
  • Six private supplies in the Nelson North area serve between 25 and 180 people each. These use water from a variety of sources and treatment ranges from none at all, to filtration with UV treatment.
  • Six subdivisions take Council supplied water, but operate a private pumping and storage system to accommodate properties located at elevations too high for Council to service.

Nelson City Council aims to achieve at least a "B-b" rating from the Ministry of Health and the water supply is designed to provide for a 1 in 60 year drought through till the year 2030. Council intends to continue meeting the water demand in the urban zoned areas but does not intend to become involved in private supplies, other than meeting its statutory obligations with respect to resource management and public health.  

Wastewater Assessment

The residential area is served by a reticulation system. Wastewater from the north of the city is treated at the Nelson North Treatment Plant and wastewater from Stoke/Tahunanui is treated at Bell Island Treatment Plant. A few residential properties and most rural properties have no reticulated wastewater system - these properties use on-site disposal systems, typically septic tanks.

Council intends to continue to manage the reticulated system. Any new systems that become necessary due to development would be to Council's requirements but funded entirely by the developers.  

Stormwater Assessment

Council maintains rivers and streams within the urban area and also provides reticulated stormwater services that discharge to rivers, streams and coastal marine environments.

The quality of discharge stormwater can have a direct and significant effect on the water it flows into. Streams and rivers in Nelson are classified (A, B, C, D or E) depending on the quality of the water. Class C water is considered to be suitable for secondary contact recreation and is aesthetically acceptable. Many of the streams and rivers in Nelson are Class D or E, which is considered to be degraded to a less than acceptable quality. The effects of stormwater quality on urban rivers and streams are still under assessment. The Resource Management Freshwater Plan amendment addresses these issues.

The full Water and Sanitary Services assessment document is also available from reception at Civic House and all Nelson Public Libraries.