This fi nal chapter outlines the main issues and challenges for future catchment management. These are both environmental and human, given that managing water resources means managing land use and the myriad of human derived demand for both land and water. Furthermore, catchments are complex human -environmental systems with temporal and spatial dynamics, and their management requires consideration of political, cultural and social process.
The importance of the catchment as a central concept in water resource planning is without doubt. The catchment defi nes the boundary condition for the available water; the maximum available resource unless water is pumped into the catchment from elsewhere. Groundwater boundaries do not always coincide with topographic boundaries but storage in aquifers can be assessed and factored into water resource availability calculations. The available water resources must support all demand within the catchment, as well as often outside of the catchment area, including potable supply, irrigation, cooling and for ecosystem services. The chemical quality of water can also be considered in this respect. Although it is not a resource use per se it does 23 Handbook of Catchment Management Edited by Robert C. Ferrier and Alan Jenkins