California has reached “peak water.” We’ve far exceeded the limits of our renewable and sustainable supply. The current severe drought has highlighted these limits and shown us the stark reality of a water system in need of new thinking, new strategies and new answers.

New research, however, shows that we can expand California’s water system by a staggering 11 million to 14 million acre-feet of water annually – more water than is used today by all the cities in the state combined. That’s enough water to revive the collapsing Delta ecosystem, bring our groundwater into balance and satisfy the needs of our agricultural communities, growing population and economy.

We know the problems. Cities, farms and ecosystems vie for limited supplies. The state suffers from a water deficit in excess of 6 million acre-feet (2.3 trillion gallons) each year, even when we’re not in drought. That amount is unsustainably drawn from two of the state’s primary natural water sources: groundwater and the Sacramento-San Joaquin Delta watersheds. Groundwater overdraft and uncontrolled and unmonitored pumping pit neighbor against neighbor. And water-exporting and water-importing regions point the finger at each other for profligate water use.

All of our water challenges are more intense during drought. Some policymakers see the drought as an opportunity to implement new water strategies for the state. But if the proposals are merely Band-Aids, they only prolong the status quo of unsustainable water use.

The good news is successful solutions already exist and are waiting for the opportunity to blossom.

The series of new studies being released today by researchers from the Pacific Institute, Natural Resources Defense Council and the University of California, Santa Barbara, provides a blueprint for proven, cost-effective and environmentally sound water options that can expand existing water supplies and cut wasteful, unnecessary demands by literally millions of acre-feet a year. These analyses identify four immediate priorities and outline the substantial savings available from each:

• Improve water-use productivity in agriculture. By expanding adoption of modern irrigation technologies and practices, farmers can reduce agricultural water use by 17 to 22 percent (around 5.6 million to 6.6 million acre-feet annually) without sacrificing revenue or crop production – a big savings in a sector that uses about 80 percent of California’s developed water supply.

• Improve water-use productivity in our homes, industries and businesses. Simple measures such as reducing leaks, installing efficient appliances, using less-wasteful manufacturing processes and replacing water-guzzling lawns with beautiful native landscapes can save between 2.9 million and 5.2 million acre-feet each year.

• Expand use of high-quality recycled water in our homes and cities. Water reuse can save 1.2 million to 1.8 million acre-feet annually, while providing a local, drought-resistant supply for a wide range of purposes.

• Expand capture and use of rainfall and stormwater runoff. More stormwater capture in just the Bay Area and urban Southern California can increase local supplies by as much as 630,000 acre-feet per year, while reducing water pollution, greening our cities and saving energy.

Some of these savings and new supplies can be captured immediately; some will be more difficult and time-consuming. But these strategies are worth the investment – and are far more robust and effective than outdated 20th century efforts to squeeze a few more drops from overtapped groundwater aquifers and dried-up rivers and streams, or by weakening protection of ecosystems.

We’re already moving in the right direction. More of our homes and farms are using efficient technologies and practices than ever before. Some efforts have been made to save and restore devastated ecosystems. There is a new awareness of the connections between water and the state’s economic and ecological health.

But much more needs to be done, including improved regulations and management, better pricing and financial tools, and expanded public education and technological innovation.

California water issues have always been contentious and likely always will be. In a crisis, it is easy for politicians to fall back on tired, old solutions that no longer work. But this is theater, not reality. Reality is acknowledging that California’s water is not unlimited, that we’ve hit those limits, and that new strategies must be adopted if the state is going to continue to support a strong and healthy agricultural and industrial economy.

Implementing the four options described above will require a mix of local, state and federal policies. But just like planting a tree that may not bear fruit for a number of years, we must begin immediately, if sustainable water strategies are going to be a permanent solution to our problems.

This Op-Ed first appeared in  The Sacramento Bee