The megapolis on California’s southern coast stretches from Ventura County on the northern end, through Los Angeles County, Orange County, down to San Diego County on the border with Mexico. It also includes the western portions of Riverside and San Bernardino counties. Altogether these six counties have a population of 20.5 million residents. According to the California Department of Water Resources, urban users consume 3.7 million acre feet of water per year, and the remaining agricultural users in this region consume an additional 700,000 acre feet.

Much of this water is imported. In an average year, 2.6 million acre feet of water is imported by the water districts serving the residents and businesses in these Southland counties. The 701 mile long California Aqueduct, mainly conveying water from the Sacramento River, contributes 1.4 million acre feet. The 242 mile long Colorado River Aqueduct adds another 1.0 million acre feet. Finally, the Owens River on the east side of the Sierras contributes 250,000 acre feet via the 419 mile long Los Angeles Aqueduct.

California’s Plumbing System
The major interbasin systems of water conveyance, commonly known as aqueducts

California’s Overall Water Supplies Must Increase

Californians have already made tremendous strides conserving water, and the potential savings from more stringent conservation mandates may not yield significant additional savings. Population growth is likely to offset whatever remaining savings that may be achievable via additional conservation.

Meanwhile, the state mandated water requirements for California’s ecosystems continue to increase. The California State Water Board is finalizing “frameworks” that will increase the minimum amount of flow required to be maintained in the Sacramento and San Joaquin rivers order to better protect fish habitat and reduce salinity in the Delta. And, of course, these rivers, along with the Owens and Colorado rivers, are susceptible to droughts which periodically put severe strain on water users in California.

At about the same time, in 2015, California’s legislature began regulating groundwater withdrawals. This measure, while long overdue, puts additional pressure on urban and agricultural users.

California’s water requirements for healthy ecosystems, a robust and growing farm economy, as well as a growing urban population, are set to exceed available supply. Conservation cannot return enough water to the system to fix the problem.

How Can Water Supplies Increase?

In Southern California, runoff capture is an option that appears to have great potential. Despite its arid climate and perennial low rainfall, nearly every year a few storm systems bring torrential rains to the South Coast, inundating the landscape. Until the Los Angeles River was turned into a gigantic culvert starting in 1938, it would routinely flood, with the overflow filling huge aquifers beneath the city. Those aquifers remain, although many are contaminated and require mitigation. Runoff harvesting for aquifer storage represents one tremendous opportunity for Southern Californians to increase their supply of water.

The other possibilities are sewage recycling and desalination. In both cases, Southern California already boasts some of the most advanced plants in the world. The potential for these two technologies to deliver massive quantities of potable water, over a million acre feet per year each, is now predicated more on political and financial considerations than technological challenges.

Recycling Waste Water

Orange County leads the United States in recycling waste water. The Orange County Sanitation District treats 145,000 acre feet per year (130 million gallons per day – “MGD”), sending all of it to the Orange County Water District’s “Ground Water Replenishment System” plant for advanced treatment. The GWRS plant is the biggest of its kind in the world. After being treated to potable standards, 124,000 acre feet per year (110 million GPD), or 85 percent of the waste water, is then injected into aquifers to be stored and pumped back up and reused by residents as potable water. The remainder, containing no toxins and with fewer total dissolved solids than seawater, is discharged harmlessly into the ocean.

Currently the combined water districts in California’s Southland discharge about 1.5 million acre feet (1.3 billion GPD) of treated wastewater each year into the Pacific Ocean. Only a small percentage of this discharge is the treated brine from recycled water. But by using the advanced treatment methods as are employed in Orange County, 85% of wastewater can be recycled to potable standards. This means that merely through water reuse, there is the potential to recycle up to another 1.2 million acre feet per year.

Needless to say, implementing a solution at this scale would require major challenges to be overcome. Currently California’s water districts are only permitted to engage in “indirect potable reuse,” which means the recycled water must be stored in an aquifer or a reservoir prior to being processed as drinking water and entering the water supply. By 2023, it is expected the California Water Board will have completed regulations governing “direct potable reuse,” which would allow recycled water to be immediately returned to the water supply without the intermediate step of being stored in an aquifer or reservoir. In the meantime, it is unlikely that there are enough uncontaminated aquifers or available reservoirs to store the amount of recycled water that could be produced.

Desalinating Seawater

The other source of new water for Southern California, desalination, is already realized in an operating plant, the Carlsbad Desalination Plant in San Diego County. This plant produces 56,000 acre feet per year (50 MGD) of fresh water by processing twice that amount of seawater. It is the largest and most technologically advanced desalination plant in the Western Hemisphere. It is co-located with the Encina Power Station, a facility that uses far more seawater per year, roughly ten times as much, for its cooling systems. The Carlsbad facility diverts a portion of that water for desalination treatment, then returns the saltier “brine” to the much larger outflow of cooling water at the power plant.

Objections to desalination are many, but none of them are insurmountable. The desalination plant proposed for Huntington Beach, for example, will not have the benefit of being co-located with a power plant that consumes far more seawater for its cooling system. Instead, this proposed plant – which will have the same capacity as the Carlsbad plant – will use a large array of “wet filters” situated about 1,500 feet offshore, on the seabed about 40 feet below the surface, to gently intake seawater that can be pumped back to the plant without disrupting marine life. The outgoing brine containing 6 percent salt (compared to 3% in seawater) will be discharged under pressure from an underwater pipe extending about 1,800 feet offshore. By discharging the brine under pressure, it will be instantly disbursed and immediately dissipated in the powerful California current.

While desalination is considered to be energy intensive, a careful comparison of the energy cost to desalinate seawater reveals an interesting fact. It takes a roughly equivalent amount of electricity to power the pumps on the California aqueduct, where six pumping stations lift the water repeatedly as it flows from north to south. To guarantee the water flows south, the California aqueduct is sloped downward by roughly one foot per mile of length, meaning pump stations are essential. The big lift, of course, is over the Tehachapi Mountains, which is the only way to import water into the Los Angeles basin.

Barriers to Implementation – Permitting & Lawsuits

The technological barriers to large scale implementation of water recycling and desalination, while significant, are not the primary impediments. Permitting and financing are far bigger challenges. Moreover, financing costs for these mega projects become more prohibitive because of the difficulties in permitting.

The process necessary to construct the proposed Huntington Beach Desalination Plant is illustrative of just how difficult, if not impossible, it is to get construction permits. The contractor has been involved in the permitting process for 16 years already, and despite significant progress to-date, still expects approval, if it comes, to take another 2-3 years.

One of the problems with permitting most infrastructure in California is that several agencies are involved. These agencies can actually have conflicting requirements. Applicants also end up having to answer the same questions over and over, because the agencies don’t share information. And over the course of decades or more, the regulations change, meaning the applicant has to start the process over again. Compounding the difficulties for applicants are endless rounds of litigation, primarily from well-funded environmentalist organizations. The failure to-date of California’s lawmakers to reform CEQA make these lawsuits potentially endless.

Barriers to Implementation – Financing

Even if permitting were streamlined, and all technical challenges were overcome, it would be a mistake to be glib about financing costs. Based on the actual total cost for the Carlsbad desalination plant, just under $1.0 billion for a capacity of 56,000 acre feet per year, the capital costs to desalinate a million acre feet of seawater would be a daunting $18.0 billion. On the other hand, with permitting reforms, such as creating a one-stop ombudsman agency to adjudicate conflicting regulations and exercise real clout among the dozens of agencies with a stake in the permitting process, billions could be shaved off that total. Similarly, CEQA reforms could shave additional billions off the total. How much could be saved?

The Sorek desalination plant, commissioned in Israel in 2015, cost $500 million to build and desalinates 185,000 acre feet of water per year. Compared to Carlsbad, Sorek came online for an astonishing one-sixth the capital cost per unit of capacity. While there’s undoubtedly more to this story, it is also undeniable that other developed nations are able to deploy large scale desalination plants at far lower costs than here in California.

Financing costs for water recycling, while still staggering, are (at least in California) not comparable to those for desalination. The GWRS water recycling plant in Orange County was built at a capital cost of $905 million – $481 million was the initial cost, the first expansion cost $142 million, and the final expansion cost $282 million. This equates to a capital cost of $7,300 per acre foot of annual yield. If that price were to apply for new facilities to be constructed elsewhere in the southland, one million acre feet of recycling capacity could be built for $7.3 billion. Until there is direct potable reuse, however, it would be necessary to add to that cost the expense of either constructing storage reservoirs, or decontaminating aquifers for underground storage.

It’s anybody’s guess, but with reasonable reforms to contain costs, and taking into account additional investments in aquifer mitigation, a budget to make California’s Southland water independent might look like this:

• 1.0 million acre feet from water recycling – $7.5 billion
• 1.0 million acre feet from desalination – $15.0 billion
• 0.5 million acre feet from runoff capture and aquifer mitigation – $7.5 billion

Total – $30 billion.
How much again is that bullet train? Water abundance in California vs. high speed rail…

While runoff capture, water recycling, and desalination have the potential to make Southern California’s coastal megapolis water independent, it will take extraordinary political will and innovative financing to make it happen. The first step is for California’s voters and policymakers alike to recognize that conservation is not enough, that water supplies must be increased. Once the political will is established, it will be necessary to streamline the regulatory process, so cities, water agencies, and private contractors can pursue supply oriented solutions, at realistic prices, with a reasonable certainty that their applications will be approved.

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Edward Ring co-founded the California Policy Center and served as its first president. This article originally appeared on the website of the California Policy Center.