The Rights in Water and Irrigation Act 1914 provides the Governor of Western Australia the power to proclaim or prescribe through regulation a Surface Water Area. A Surface Water Area is proclaimed for the purposes of regulating the taking of water from watercourses and wetlands. An area is proclaimed, or prescribed through regulations, where there is a need for systematic management of the use of water. The proclamation is made on the recommendation of the Department and must first be tabled before both Houses of Parliament. Proclaiming or prescribing an area has the effect of allowing the use of water for commercial activity under a licence. Where an area has been proclaimed, the provisions of Division 1B of Part III of the Act apply to surface water in that area. This allows comprehensive management of water uses in that area. This dataset defines the boundaries which are proclaimed as Irrigation Districts (IDs) under the Rights in Water and Irrigation Act, 1914 (RIWI Act). In addition to the boundary definition within the Act these areas are subject to Division 1B of the Act which implements licensing of water use from watercourses and wetlands in the area. Irrigation districts are areas where the Water Corporation or another service provider may construct work and supply water to land owners for irrigation purposes. This dataset is the result of combining three existing datasets; RIWI Areas, RIWI Irrigation Districts and RIWI Surface Water Areas. It replaces all three. This dataset was formerly known as RIWI Act, Surface Water Areas and Irrigation Districts (DOW-019)

For the purposes of groundwater resource management, the state of Western Australia is divided into groundwater areas proclaimed under the Rights in Water and Irrigation Act 1914. These groundwater areas are further subdivided into groundwater subareas. The subareas are not proclaimed, but are administrative boundaries used to manage the abstraction and licensing of groundwater resources.

Groundwater areas stored in WRIMS (Water Resource Information Management System). For the purposes of groundwater resource management, the state of Western Australia is divided into groundwater management areas or groundwater areas. The extraction and licensing of groundwater resources are managed within groundwater areas in order to ensure environmental requirements are met and to prevent over extraction of the resource. Some Groundwater Areas stored in WRIMS do not accurately reflect the official gazetted Groundwater Area boundaries, however a program is currently underway to realign the boundaries. Please contact the data steward for more information.

Surface Water areas stored in WRIMS (Water Resource Information Management System). For the purposes of Surface Water resource management, the state of Western Australia is divided into Surface Water areas. The extraction and licensing of surface water resources are managed within surface water areas in order to ensure environmental requirements are met and to prevent over extraction of the resource. Surface Water Management Areas for Western Australia were derived in consultation with the regional offices, geometry is based on hydrographic subcatchments. Regional Department of Water and Environmental Regulation officers identified areas of similar management requirements to define boundaries. Management areas will be used for licencing and administrative purposes.

Areas are proclaimed under the following act - Rights in Water And Irrigation Act. Rivers classification mapping is developed to control the extraction and licensing of stream water. Those rivers and tributaries included extend between Perth and Margaret River. Data examined in October 2002 by the Resource Management GIS Branch. Data was found to be of unknown origin, quality, custodian or date. No documentation was found but this data is suspected to have been generated to support the Statutory Referral System. This dataset was formerly known as RIWI Act, Rivers (DOW-018)

Surface Water Management Areas for Western Australia were derived in consultation with the regional offices, geometry is based on hydrographic subcatchments. Regional Department of Environment officers identified areas of similar management requirements to define boundaries. Management areas will be used for licencing and administrative purposes. Purpose: The Surface Water Management Area data was developed in order to give a clear understanding of surface water availability and to provide management tools to make good water allocation and natural resources management decisions. Dataset was formally known as Surface Water Management Areas (DOW-020)

This dataset is the Western Australian component of a national Drainage Divisions and Basins dataset overseen by the Australian Water Resources Council. It is part of a hierarchical order of 4 datasets ranging from Subcatchments through Catchments and Basins to Divisions. The Subcatchments, Catchments and Basins are hierarchically ordered subsets of the Divisions dataset. The drainage divisions of Western Australia, derived from catchment boundaries defined at various scales. This dataset is derived from a subset of lines from the Hydrographic Catchments - Subcatchments data. This dataset was formally known as Hydrographic Catchments - Divisions (DOW-016)

Surface Water subareas stored in WRIMS (Water Resource Information Management System). Surface Water Allocation Subareas for Western Australia were derived in consultation with the regional offices, and geometry is based on hydrographic catchments. Regional Department of Water and Environmental Regulation officers identified areas of similar management requirements to define boundaries or aggregations of hydrographic subcatchments. Regions with notable management concerns both currently and possibly in the future were identified to become management subareas. Allocation subareas will be used in the calculation of sustainable yields, flow rates and ultimately these calculations will be available for water allocation and natural resource management decisions. In addition, native vegetation clearing values have been calculated for each of the subareas located within the extent of the South-West region of Western Australia, for input into the allocation process. The Surface Water subarea data was developed in order to give a clear understanding of surface water availability and to provide management tools to make good water allocation and natural resources management decisions.

Surface Water Management subareas for Western Australia were derived in consultation with the regional offices, and geometry is based on hydrographic catchments. Regional Department of Environment officers identified areas of similar management requirements to define boundaries or aggregations of hydrographic subcatchments. Regions with notable management concerns both currently and possibly in the future were identified to become management subareas. Management subareas will be used in the calculation of sustainable yields, flow rates and ultimately these calculations will be available for water allocation and natural resource management decisions. In addition, native vegetation clearing values have been calculated for each of the subareas located within the extent of the South-West region of Western Australia, for input into the allocation process. The Surface Water subarea data was developed in order to give a clear understanding of surface water availability and to provide management tools to make good water allocation and natural resources management decisions. Dataset was formerly known as Surface Water Management Subareas (DOW-021)

This dataset is the Western Australian component of a national Drainage Divisions and Basins dataset overseen by the Australian Water Resources Council. It is part of a hierarchical order of 4 datasets ranging from Subcatchments through Catchments and Basins to Divisions. The Subcatchments, Catchments and Basins are hierarchically ordered subsets of the Divisions dataset. Catchment boundaries have been defined for more than 3400 key sites on streams throughout Western Australia. The Subcatchments dataset contains polygons from which the Catchment boundaries are derived. This catchments dataset is derived from this on the basis of the CATCH_NAME field, determined by the Scientific Custodian. This dataset was formerly known as Hydrographic Catchments - Catchments (DOW-014)