Water allocation

Surface Water

Effects of Taking Stream Water

Abstracting surface water can have the following effects:

• Reduce water levels and change flow regimes in rivers and streams and water levels in lakes, dams and wetlands
• Increase the frequency and duration of low flows, which can result in reduced contaminant assimilation capacity, poorer water quality (reduced dissolved oxygen levels and elevated water temperatures) and a reduction in available habitat.
  These may all have adverse effects on the freshwater ecosystems and on tangata whenua values.

Numerous small and high use streams in the region, and larger waterbodies where water quality is already degraded, are all potentially vulnerable to these effects.

Water allocation from rivers and streams, especially in summer when flows are at their lowest and demand is generally at its highest, will be carefully managed so as to safeguard the life-supporting capacity of these water bodies.

Water intake structures may cause fish and other freshwater biota to be drawn into the structures or trapped on intake screens. These effects will be avoided by ensuring that water intake structures are suitably designed and operated.

The policy direction of the ARC on taking water from surface water changed with the introduction of the Proposed Auckland Regional Plan: Air, Land & Water.

In areas where groundwater is available, the taking of groundwater must be considered in preference to the taking of water from rivers and streams. If surface water is sought, then the taking of water from rivers and streams during the six month period from May to October inclusive for use or off-stream storage is considered more appropriate than taking during the alternative six month summer period November to April inclusive.

Any new consent to take water from run-of-stream flow is likely to be subject to minimum flows or other flow regime requirements through conditions on consent. Alternative water sources may be required when there are restrictions on abstraction during periods of low stream flow. Therefore stream takes should no longer be considered a secure supply of water during the height of summer.

High Use Streams

A number of streams in the Auckland Region are under pressure from demands for water abstraction, or use by a number of users. The values of these streams are threatened by high use or abstraction and they are identified as ‘high use streams' in the Regional Plan. The purpose of this management area is to ensure that high use or over abstraction does not threaten the life-supporting capacity of these streams. Ecological, amenity and use values are also important. Accordingly, other than the ability to take water as permitted by section 14 of the RMA, the majority of abstractions will need to be carefully evaluated and managed. High Use Streams are all the streams within the following catchments and sub-catchments (from north to south):

• Whangaripo Stream (a sub-catchment of the Hoteo River catchment);
• Mahurangi River;
• Waitoki, Waikahikatea and Waipapakura Streams (sub-catchments of the Kaukapakapa River catchment);
• Waimauku Stream and Kumeu River (sub-catchments of the Kaipara River catchment);
• Puhinui Stream in Manukau City;
• Taitaia Stream (a sub-catchment of the Wairoa River catchment)
• Hays Creek;
• Ngakoroa, Mauku and Waitangi Streams in Franklin District.

The area in which these High Use Streams Management Areas are located are identified on the PARP:ALW October 2004 Map Series One (sheets 1-54). They are described in sections 3.2 and 3.7 of the PARP:ALW June 2005.