By Peter H. Gleick, Heather Cooley and Amanda Bielawski
Special to The Examiner
Severe drought. Dying fish. Fallowed farmland. Disappearing groundwater. Failing wells. Communities without safe drinking water.
Even longtime observers of California’s water challenges are increasingly distressed by the problems that are piling up.
Despite a promising start to our water year with last December’s storms, drought has come roaring back, a drought that we now know is being intensified by human-caused climate change. The first three months of 2022 have been the driest in the state’s recorded history, and the winter snowpack is vanishing fast. The state’s major reservoirs have nowhere near enough stored water, and deliveries of water to many farms, cities and industries this year will be deeply curtailed.
There’s good news, however. The Pacific Institute just released a new assessment of a set of urban water strategies for California that offers concrete solutions for saving water through improved water-use efficiency measures, while boosting local water supplies by expanding water reuse and capturing more stormwater that falls on our urban areas.
California cities have made important progress over the last several decades in reducing total and per-person water use because of three key achievements: efficiency standards for new appliances, fixtures and landscapes; utility-led rebate programs; and efforts to find and fix leaks. Those efforts have led to a 30% drop in total urban water use statewide – a remarkable improvement in efficiency!
The new study, however, shows that another 30% savings is possible simply by bringing California homes, businesses and industries up to current standards. Newer technologies that exceed current standards for using water efficiently could save even more. Even the San Francisco Bay area, which has made more progress in recent years than some other parts of the state, could cut current urban use by another 25%.
These savings include: reducing indoor water use with better appliances, toilets, faucets and showerheads; and cutting outdoor water use by changing from water-hungry lawns and landscapes to low-water-using gardens and more careful irrigation systems. Every gallon of water we save is a gallon of water that stays in our stressed rivers and streams or remains in our depleted reservoirs for use later.
These water savings also cut energy use and greenhouse gas emissions because of the high energy costs of running our water systems.
The best news of all? These improvements in efficiency are far cheaper than any potential new source of supply.
California can also dramatically increase the reuse of high-quality treated wastewater. We’re making progress in this area, but slowly. At present, we reuse around 720,000 acre-feet of wastewater — about 24% of the wastewater we produce. But the vast majority of our valuable treated wastewater gets dumped into the ocean.
The new study shows we could more than triple water reuse across the state, adding up to 2.1 million acre-feet more to local supplies, greatly relieving pressure on our overburdened rivers and streams. The South Coast cities have the greatest untapped resource of treated wastewater and are developing plans to expand reuse. The San Francisco Bay area also has a tremendous amount of this valuable resource that can be reused and has been far slower than southern California to tap it, only reusing around 9% of the current wastewater we produce.
We can also do far more to capture and reuse stormwater that comes in the winter rainy season. Historically, our cities have seen stormwater as a liability, to be channeled, diverted and shunted away from our streets and pushed out to the ocean. Even in a dry year, more than half a million acre-feet of rain falls on impervious city landscapes that overlie groundwater systems that could — with smarter urban infrastructure — capture and store that water. In a wet year, as much as 3 million acre-feet of stormwater could be available. Far more could be done to capture winter stormwater flows to enhance local water supplies.
San Francisco has been innovative in applying some of these strategies already. For instance, on the efficiency side, San Francisco’s Public Utilities Commission’s 2009 retrofit-on-resale ordinance requires high-efficiency plumbing fixtures to be installed in all residential single and multi-family housing upon resale. The program is projected to save over 2.5 billion gallons in cumulative savings through 2045.
San Francisco’s Moscone Convention Center has pursued all three strategies — efficiency, reuse and stormwater capture. The Center’s district-scale onsite water system treats and reuses rainwater collected from its roof, condensate from the building’s cooling system and foundation drainage, offsetting about 15 million gallons per year of potable water for use in toilets and urinals, landscape irrigation and to refill trucks for cleaning streets throughout San Francisco.
While these examples show what is possible, much more must be done to rapidly scale these strategies across the state. In addition to narrowing the gap between water use and supply, these strategies will provide local communities with valuable co-benefits. For instance, withdrawing less water from over-tapped water sources comes with the potential to provide rivers with more instream flow, protecting ecosystems and threatened species. These strategies can also contribute to addressing critical water equity issues by building water supply reliability with the goal of making water more accessible — for all. Further, by reducing reliance on imported water, we can reduce energy use and greenhouse gas emissions, contributing to climate mitigation goals.
The new study addresses untapped potential for California’s cities, but we also know the agricultural sector, which uses 80% of the water humans use statewide, has great potential to grow more food with less water by changing irrigation practices and technologies and shifting crop types. The Pacific Institute prepared an earlier assessment highlighting this potential and California’s farmers are moving to make many of these improvements in the face of growing drought, shortages and the need to end massive overdraft of groundwater, but far more must also be done in this sector. An updated assessment for California agriculture is needed.
All of these strategies will require focused smart investments and policies, but they also will require our water utilities and institutions to think differently, moving from old-style, outmoded, expensive and environmentally damaging water systems to more modern strategies.
In the short term, improvement in water-use efficiency and conservation can help us deal with the severe drought now facing us. In the longer term, investments in efficiency, reuse and stormwater capture can help us build a far more resilient, equitable and sustainable water future.
Peter H. Gleick is senior fellow and co-founder of the Pacific Institute, an Oakland-based global water think tank that creates and advances solutions to the world’s most pressing water challenges. Heather Cooley is the Pacific Institute’s director of research and Amanda Bielawski is its director of communications and outreach.