Water Demand and Supply Statement for Kangaroo Island

What are the main findings of the Kangaroo Island Water Demand and Supply Statement?

The main finding of the Statement is that, for both drinking and non-drinking quality water, sufficient supplies exist and no shortfalls are expected to occur before 2050.

Kangaroo Island is heavily reliant on surface water, typically captured through farm dams, and in many parts of the region rainwater is the main source for household drinking supplies. SA Water provides reticulated water within the bounds of the Middle River Water Supply System and from the Penneshaw Desalination Plant on Dudley Peninsula. The combined systems supply water to around half the KI population.

The main demands for drinking quality water include the residential population, non-residential uses and tourism. Growth in residential water use will be driven by population growth, with flow-on impacts for non-residential uses. Following residential and non-residential demand, visitors to the Island are the major users of drinking-quality water, accounting for approximately 14 per cent of yearly potable water demand.

Total potable water supplies currently available on the Island amount to 875.6 ML annually and this compares to potable water demand of approximately 673.4 ML. Therefore, on average, there is a surplus of approximately 202 ML of drinking quality water on the Island per year. Due to anticipated growth in demand, the surplus is expected to reduce to around 22 ML by 2050.

The current demands for non-potable water are driven by plantation forestry, irrigated crops and livestock. The current supply of surface water is estimated at 76.3 GL and the surplus for non-potable water is estimated around 50 GL. The Statement projects surface water supply to 2050 on the basis of two climate change scenarios and estimates the future surplus ranging from 51 GL and 34 GL.

Why is the Statement important?

The KI Water Demand and Supply Statement provides a region wide summary of drinking and non-drinking water supplies and demands. The statement ensures that projections of future water shortages are identified with sufficient lead time to avert the shortfalls by developing regional demand and supply based solutions.

The preparation of the Statement is a requirement of the Water for Good plan and the Water Industry Act 2012.

Who developed the Statement?

The KI Water Demand and Supply Statement was developed by the Department of Environment, Water and Natural Resources (DEWNR) with the assistance of the Water Resources Task Force, an advisory committee to the Kangaroo Island Natural Resources Management (NRM) Board. Chaired by the KI NRM Board Presiding Member the Task Force includes representatives from the KI NRM Board, KI Council, AgKI, Eco-Action KI, SA Water and SA Environment Protection Authority.

See the Kangaroo Island Water Demand and Supply Statement and Frequently Asked Questions document for further information.

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