ABSTRACT
California shares the water management challenges of many regions facing rapid population growth and constraints on supply expansion. Environmental concerns have curtailed the scope for large new surface storage projects, and in many cases are resulting in reductions in human uses. Widespread basin overdraft limits the potential of native groundwater as a source of expansion. As a result, the focus of water planning has progressively shifted toward portfolio approaches, which seek to meet urban demand growth by augmenting non-traditional supply sources (such as recycling, underground storage, and desalination) and by improving the efficiency of use of existing supplies (conservation and the market-based reallocation of water rights).
