Property Plan – Location
The assessment for the property requires an accurate plan of the property (scale 1 : 2000) and a district location. Certificate of Title or Litho plan is useful.

Aerial Photos/Contour Plan
The latest aerial photos with 2 – 5 metre contour plans are available from the Department of Land Administration – Midland – Perth WA. They are an excellent base plan for property assessment.

Catchment Areas
Contour plans and stereoscopic coverage of the catchment areas assist with the property assessment for catchment area, topography, vegetation, natural features such as large rock outcrops, ridge lines, valley depressions. Land capability plans where available are used to assess soil types.

Surface & Sub Surface Flows
The information provided from the contour plans and the stereoscopic photos help to assess the potential winter surface runoff from the catchment areas. The soil types and profiles are used for potential recharge rates of the sub surface aquifers.

Agency Regulation & Requirements
The private and Government agencies involved in the hydrological assessment of a property for subdivision include Property Planners, Department of Water, Agriculture Department, Department of Environment and Conservation, Department of Planning and Infrastructure, Environmental Protection Agency, Local Shires and Land Care Groups.

Potential Water Use
The water demand for property development is assessed from annual rainfall, potential crops, soil types, topography, location.

Water Quality
Water quality assessment is undertaken by an independent Laboratory for Salinity, pH – acidic or alkaline, Iron content, chemicals, nutrients and solids.
Different proposed property uses require different water quality. E.g. Domestic or grey water, stock or irrigation demands.