Marlborough Sounds Resource Management Plan A normal excess of availability over demand is due primarily to a high rainfall and a relatively low demand. Annual rainfall varies between a maximum of 2400 and a minimum of 1200 mm throughout the Sounds, compared to Blenheim’s total of around 700 mm per year. This abundance of rainfall is exemplified in the permanent nature of most river regimes, luxuriant vegetative growth and high watertables. The exceptions are areas located along narrow isthmus such as the one separating Queen Charlotte Sound from Kenepuru Sound. These areas generally have less storage capacity in surface water bodies and receive less rainfall. In areas of the Sounds there is at times, a seasonal water shortage. It is therefore important to ensure that adequate storage facilities are available. Storage is generally able to provide for any temporary shortfall. In addition, the use of groundwater resources needs to be encouraged. The high watertable levels within the Sounds and particularly the hinterland area, means there is an abundance of, largely unused, groundwater. Current pressure on water resources is only likely to adversely affect some of the rivers and streams within the Marlborough Sounds area, in a short-term seasonal manner, during a dry year. The policies will establish an environmental bottom line flow, based on the low flow of a particular catchment, to guide and ensure sustainable water management. The policies will work in with a precautionary approach towards the issuing of water permits and careful monitoring of water quantity within the freshwater bodies of the Marlborough Sounds and freshwater habitats. 3.2.5 Objectives and Policies Objective 1 That the natural functioning of ecosystems is not disrupted by the taking, use, damming and diversion of fresh surface water. Policy 1.1 Adopt a precautionary approach towards the allocation of surface water resources. Policy 1.2 Give priority to the maintenance of fresh water flows over abstraction from permanently flowing rivers. Policy 1.3 Avoid adverse environmental effects on fresh water eco- systems from the taking of fresh surface water. Generally this will mean not more than 30% of the five year seven day low flow is allocated for abstraction. Policy 1.4 Encourage the use of groundwater (where this is available) as an alternative to surface water, provided it does not have an adverse effect on the environment. Policy 1.5 Encourage, and where appropriate require, adequate water storage facilities in areas affected by seasonal water shortages, while avoiding, remedying or mitigating adverse environmental effects. Policy 1.6 Activities, resource use, development and subdivision should not be dependent upon water being available from the natural resource base when disruption to the natural functioning of the ecosystems is likely. 3 - 6