The land assets of the Region include productive agricultural land, soil, mineral and forestry resources, and conservation areas (Figure 4). The Swan Region is a major contributor of fresh food for the Perth market, with around 5,000 hectares of irrigated land utilised for this purpose. In addition, there is around 190,000 hectares of land utilised for the production of cereal and other crops. The farm gate value of irrigated agriculture, grains and livestock production for the Region is valued at over $320m in 2010/11 (Australian Bureau of Statistics 2014a).
Agricultural assets are under significant threat from urban expansion, competing land uses, high production costs, declining soil health and climate change (Perth Region NRM 2014a). Inadequate protection of high quality agricultural land from urban development is a critical issue affecting long-term agricultural production in the Swan Region (Figure 5). The Department of Agriculture and Food’s (WA) report card for the south west of Western Australia on sustainable natural resource use in agriculture revealed that progress has been made in terms of managing water and wind erosion, but soil acidity, water repellence and nutrient export continue to be of concern (Department of Agriculture and Food WA 2013). Other issues include dryland salinity in the Ellen Brook and Brockman River catchments and soil compaction in viticultural areas.
Basic raw materials (BRM) such as sand, limestone, gravel and clay are vital for the housing and construction industry. Lime sand is also exported to inland areas to correct soil acidity and is an essential treatment for the sustainability of inland farming systems, particularly cropping systems. These materials are always assumed to be readily available, however, a series of reports from government and industry have highlighted growing problems in the availability of BRMs. This was one of many factors that triggered the Strategic Assessment of Perth and Peel to address land and resource availability for further development and the impact on natural assets.