The Times' recent story, "Water shortage worst in decades," illustrates an often forgotten fact. Southern California is really a semi-arid desert -- brought to life by water supplies from the Colorado River, the Owens Valley and the State Water Project to supplement our local supplies. Our reliance on this imported water to meet the region's future needs puts us at ever greater risk. Future water supply reliability will increasingly depend on local self-help measures such as conservation, reuse, more below-ground storage of surplus supplies and even desalination.

But more important and far more urgent is the serious threat we face today of real water shortages for much of the state because of the crisis in the Sacramento-San Joaquin River Delta. Collapse of its strained ecosystem and its labyrinth of unstable levees from flood or earthquake could gravely reduce, or even suspend, deliveries from the State Water Project serving not only Southern California but users in the San Francisco Bay Area, the San Joaquin Valley and the Central Coast. California's entire economy is at risk.

How do we address these threats to the viability of our quality of life and our economy? First, we offer our support for a statewide solution for the delta, which would address ecosystem concerns and stabilize the water supply. Such a solution must include a new water conveyance infrastructure, funded by those who benefit from the system improvement. Second, we must move forward on Gov. Arnold Schwarzenegger's call for a statewide 20% "across the board" water conservation effort. The business community can demonstrate its leadership in this effort. Third, Southern California's Metropolitan Water District, local water agencies and the private water sector should begin to explore new strategic efforts in addition to their conservation and reuse initiatives. They should maximize local water resources by partnering -- employing transportation and exchange arrangements -- to use the extensive pipeline network and underground storage facilities throughout Southern California. Other regions should consider similar plans.

Finally, our state leaders need to reach agreement on a comprehensive statewide water infrastructure plan, including bond funds for a delta solution and local water reliability projects.

All this will cause our water service to cost more in the future. But going without a critically needed water supply is simply not an option.

George Deukmejian, Pete Wilson, and Gray Davis are former governors of California and charter members of the Southern California Leadership Council.

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