How Do We Fix the Salton Sea? Part 1 | KCET
How Do We Fix the Salton Sea? Part 1
The Salton Sea, California's largest lake, will die unless the state throws a staggering amount of resources at it in the next decade or so. letting the sea die will cause significant harm to both public health and wildlife in Southern California and beyond. But the leading contender for a fix may prove to be only a short-term solution.
As a result of water diversions from Imperial Valley agriculture to coastal urban use, the 340-square-mile Salton Sea is drying up. That means the loss of crucial wildlife habitat, and it also means that lakebed dust will further pollute the Imperial Valley airshed, which already has some of the dirtiest air in the country.
The State of California agreed 15 years ago to have a plan in place by 2017 to preserve wildlife habitat and public health by restoring at least part of the Salton Sea. That plan is about 15 years behind schedule, in large part because few in state government are willing to foot the estimated $18 billion price tag. But as momentum builds to force the state to fix the sea, it turns out the state's preferred plan might not survive the next big quake.
Though it's been languishing, the state has actually had a final plan in place to restore part of the Salton Sea since 2007. Here's a map of what the newly engineered Sea would look like:
Under that plan, the majority of the Sea would be allowed to dry out. The resulting toxic lakebed dust would be kept from polluting the air by a combination of sand fencing, strategically planted irrigated vegetation, and chemical dust control, possibly including using the local brine to create a hard, salty crust to seal in the dust.
The northern two-thirds of the sea's shore would host a diked-off 45,000-acre "marine sea" of saltwater, replenished by freshwater from the Colorado River and managed to keep its salinity at about the same level as ocean water. The marine sea, which would stretch from Bombay Beach on the east shore to near the intersection of Routes 78 and 86 on the west shore, would be kept at a depth of about 40 feet.
The south end of the sea, near the agricultural communities of Niland and Westmoreland and the Salton Sea National Wildlife Refuge, would be maintained as about 62,000 acres of saline habitat at about the Sea's current salinity, also replenished by Colorado River water. The saline habitat here would be interspersed with geothermal development areas, and would likely also host some solar power facilities.
In the center of the sea, surrounded by the marine sea in the north and the saline habitat in the south, somewhere around 106,000 acres of the Sea -- 166 square miles -- would be allowed to dry up. In the deepest parts of the present-day Sea two brine sinks would remain, all that's left of the original Salton Sea, with water four or five times as salty as the ocean covering about 17,000 acres.
Those brine ponds would be used to collect excess salts from the two habitat areas. That's important: even fresh water from the Colorado carries a bit of dissolved salt, and adding it to the habitat areas means adding that salt to the mix. As water evaporates and more is added, the total salt concentration in the habitat areas would climb. Flushing some of that salty water out onto the exposed playa would lower the total salt concentration in the habitat water.
As envisioned in the plan's 2007 Final Environmental Impact Statement, major construction on this restoration plan would be over by 2025, with all the finishing details done ten years later. But that assumed a construction start date in 2014 after a five-year planning process. None of that has really started.
And real-life problems have emerged since 2007. The plan was drafted assuming that the Colorado River could provide 717,000 acre-feet of water to the project per year from 2018 until 2078. That's almost a tenth of the 7.5 million acre-feet of Colorado River water allocated to California, Nevada, and Arizona combined each year, and that allocation was set in 1922. In an average year, the Colorado River carries about 4 million acre feet per year less than the 15 million assumed in 1922, and given the protracted droughts to which the Southwest is increasingly subject, we may not see many average years anymore.
Further, the plan's design relies on berms to keep the marine and saline habitats separated from the dried-out playa. The marine sea would be hemmed in by 52 miles of rock and earth berm standing about 47 feet high and as wide as half a mile at the base. That's a lot of rock and earth, and moving it into place will be a time-consuming, expensive process. The berms holding in the saline habitat water will be smaller, but more complex.
And just where the marine sea would adjoin the saline habitat area on the sea's east side, near Bombay Beach, is the south end of the San Andreas Fault. Just one of the major faults in the Salton Sea area, this section of the San Andreas is thought capable of producing a quake of magnitude 8.1. Such a quake is generally considered overdue. A 7.2 shaker on the nearby Laguna Salada fault rocked the area in the spring of 2010.
In other words, the area is quake-prone. Earthen structures are particularly vulnerable to damage in large quakes, especially when -- as would be the case in a redesigned Salton Sea -- those structures are built atop waterlogged sediments, which can liquefy in a strong temblor.
Is there an alternative? Environmental Studies professor Tim Krantz at the University of Redlands thinks so. Krantz, who worked to prepare the state's 2007 plan, has found merit in an alternative that seems potentially simpler -- though not necessarily cheaper.
It's called the Sea to Sea plan, because it would create a link between the Salton Sea and the Sea of Cortez 125 miles south. In the Sea to Sea plan, seawater from the Sea of Cortez -- also called the Gulf of California -- would be moved via a canal and pumps to the Laguna Salada, a dry lake in Mexico west of Mexicali and just south of the US border. The dry lake would be diked down the middle, and the ocean water stored in a reservoir on the west side.
Geothermal energy would be used to desalinate the ocean water at Laguna Salada, then the resulting freshwater would be pumped over the slight rise between the Laguna Salada basin and the Salton Basin. The Salton Sea is about 270 feet downhill from the top of that rise, so hydroelectric turbines could be built to capture some of the energy the freshwater expends in going down to the Salton Sea.
Once it's there, that water replenishes the Sea without adding extra salts, so that the need to extract brine from the Sea would be lessened. (The Whitewater River and Coachella Canal would still bring some salt into the Sea, so the brine problem wouldn't be completely solved.) Waste brine from the Laguna Salada desalination plants would be discharged onto the playa, so that the salts could slowly work their way back toward the Sea of Cortez.
The fresh water inflow into the Salton Sea would create a stable salinity and potentially stable shoreline, raising the desirability of lakefront real estate, with possible subsequent increases in property tax revenue to offset some of the up to $10 billion the Sea to Sea project might cost.
And, Krantz points out, the new desal plants could offer an additional source of drinking water to Mexicali's million or so thirsty residents, along with a new body of water on Laguna Salada offering potential for resort development. "Laguna Salada could be Mexicali's Riviera," says Krantz.
For all its relative simplicity, the Sea to Sea plan would still be daunting. Before the recent water diversions to urban from Imperial Valley farms to urban users, the Salton Sea was slowly dwindling and getting saltier with annual inflows of about 1.3 million acre-feet per year. With those inflows cut to the bone, you'd need more than that 1.3 million acre-feet of desalinated water to bring the Sea back up to its historic level.
And though Krantz's version of the Sea to Sea plan does offer some benefits to Mexico and the state of Baja California, Mexican officials have almost a century's backlog of reasons not to trust gigantic water proposals coming from El Norte. Approval for the necessary infrastructure is far from a slam dunk.
It all boils down to what in the medical trade would be called "heroic measures" to save a life that's almost certainly doomed without them and may be doomed anyway. The Salton Sea's natural life cycle would be to dry up and become a hypersaline sump until the next catastrophic flood brought the full flow of the wild Colorado River back to the Salton Basin a decade or two centuries later to fill it up again.
We've built a string of dams on the river to ensure the Sea won't get replenished naturally in our lifetimes, but at the same time we've built a complex society nearby that can't tolerate the inevitable resulting alkaline particulate matter and sulfur stink of the dying sea. We've painted ourselves, ecologically speaking, into a corner. And there's pretty much no way out that doesn't mean leaving wet paint footprints on the living room carpet.
Part 2, covering plans from the Imperial Irrigation District, coming soon.
For ongoing environmental coverage in March 2017 and afterward, please visit our show Earth Focus, or browse Redefine for historic material.
KCET's award-winning environment news project Redefine ran from July 2012 through February 2017.
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