Technical aspects of integrating water quality science in freshwater and coastal environments

C W Hickey, R B Williamson, M O Green, Richard G Storey
Auckland Council Research and Evaluation Unit, RIMU
Publication date:

Auckland Council is currently engaged in a number of significant programmes and projects that focus on how Auckland’s natural resources are managed. Two of these programmes are in response to changes at a national level, the National Policy Statement: Freshwater Management 2014 (NPS-FM) with implementation through council’s Wai Ora Healthy Waterways Programme and Marine Spatial Planning (MSP) as a preliminary means of addressing aspects of the New Zealand Coastal Policy Statement (NZCPS).

There is a clear overlap between the two programmes in the area of water quality, not least the natural ‘river to sea’ connection between the land, fresh water and coastal environments. A key area of overlap occurs around water quality parameters and the setting of objectives and limits. The latter are required in fresh water by the NPS-FM, whereas objectives and limits are not required by the NZCPS in the coastal environment (though the intent is indicated in Policy 7). It is envisioned that determining values, and developing objectives and limits for the coastal environment would be the logical next steps arising from the MSP process.

As a first step, in 2012 Auckland Council commissioned a report which provided a preliminary assessment of limits and guidelines available for classifying coastal waters (Williamson et al., 2016). A similar investigation focusing on the freshwater environment was identified as necessary to develop NPS-FM implementation strategies. The information from the two studies could then be used to guide application of scientific knowledge of water quality to an objectives and limits framework, thereby supporting uses and values of Auckland’s fresh and coastal water resources in an integrated manner.

The purpose of this report is to provide:

- a technical assessment of the existing guidelines and limits used to classify freshwater for water quality management purposes;

- an understanding of the technical considerations required to integrate coastal and freshwater science for the purposes of establishing objectives and limits under the National Policy Statement: Freshwater Management 2014 and the New Zealand Coastal Policy Statement.

Auckland Council technical report, TR2016/039.

See also:

Preliminary assessment of limits and guidelines available for classifying Auckland coastal waters, TR2017/035

Last updated: 2017-06-21