Surface water and groundwater
There are two legislative acts that establish the framework for managing and allocating water resources in the Ord region:
Under the Acts, the right to the use, flow and control of the water in watercourses, wetlands and underground water sources is vested in the Crown, except as appropriate under a written law.
The Department of Water (WA) and the Department of Natural Resources, Environment, The Arts and Sport (NT) assist their respective Ministers with the water resource management powers and functions set out in the Acts, including:
- regulating the taking of water from prescribed water management areas
- proclaiming water management areas across the State for surface water and groundwater.
The following surface water management areas were proclaimed by the Western Australian Department of Water in the Ord region as shown in Figure A1.
- Ord River and Tributaries – the majority of that part of the Ord region located in Western Australia
- Ord Irrigation District
- Wyndham Water Supply Surface Water Area – small area in the north west around Wyndham.
Figure A1. Map of surface water management areas in the Ord region
The Canning–Kimberley proclaimed groundwater area was proclaimed by the Department of Water in the Ord region as shown in Figure A2.
Figure A2. Map of groundwater management areas in the Ord region
Water management areas were not proclaimed by the Department of Natural Resources, Environment, The Arts and Sport (NT) for the portion of the Ord region that lies within the Northern Territory. Consequently, there is no known abstraction of water from this portion of the Ord region, and the inclusion of information regarding the management of water resources in this area is not deemed material to this water accounting report.
Water management plans
The Western Australian Department of Water prepares water management plans to specify how water resources are to be shared between competing needs in particular areas. Management plans establish sustainable diversion limits for water resources and define the water available for use. The limits are established to ensure that sufficient water is retained in the resources to protect aquatic ecosystems and meet specific social and cultural needs.
The Ord River Water Management Plan (Department of Water, 2006) sets down sustainable diversion limits for entitlements from the Ord River. The plan also defines the environmental water provisions for the lower Ord River, set with consideration for ecological, economic and social impacts, including recognition of cultural significance to the Miriuwung and Gajerrong peoples.
Water management plans and allocation plans have not been developed for groundwater resources in the region, due to the limited use of groundwater compared to the availability.
Environmental water management
Environmental water legislation
The Environmental Water Provisions Policy for Western Australia (Water and Rivers Commission, 2000) guides the Department in water allocation planning and decision-making in relation to allocating water to the environment. The policy describes the role of environmental water regime requirements and environmental water provisions in setting the sustainable diversion limit for a water resource.
Environmental water provisions
Environmental water provisions are specified in water management plans, and are expressed as a water regime requirement, i.e. a minimum flow regime to be achieved at key locations within the management area. Responsibility for achieving these flow regimes are placed on the storage operator, and are defined in licence conditions as part of operating strategies.
The Ord River Water Management Plan (Department of Water, 2006) defines environmental water provisions to protect the ecological condition of the lower Ord River. Environmental water provisions set with consideration for ecological, economic and social impacts, including recognition of cultural significance to the Miriuwung and Gajerrong peoples.
The Water Corporation (WA) has an obligation to operate water levels in Lake Argyle and Lake Kununurra and monitor releases to maintain specific flow rates in the lower Ord River. The Department of Water monitors flows at key locations in the lower Ord River to ensure that water regime requirements are met.
Further information regarding environmental water provisions for the 2010–11 year is provided in the Environmental benefit note.
Organisations responsible for water management
The organisations with management responsibilities for regulating water resources and supplying water services in the region are shown in Table A1.
Water resources managed
Department of Water (WA)
Ord River and tributaries
|Department of Natural Resources, Environment, The Arts and Sport (NT)||
Water Corporation (WA)
Urban water supply infrastructure at Halls Creek, Wynham and Kununurra
Ord River Irrigation Area infrastructure