California’s underground movement to save water

Only in California, after almost five years of a desolate drought, could the arrival of El Nino, with predictions of rain so heavy that mudslides and flooding would be the norm, sound like salvation. This version of El Nino promises to be so bad that meteorologists have labeled it “Godzilla.” El Nino, by default, warms the Pacific Ocean, but this time around it’s brewing the water a few degrees higher than normal. That’s causing the subtropical jet stream that typically moves south of California, to shift further north. All that promises to bring the brunt of most of its storms squarely at the state.

“Riding that jet stream will be a series of storms like a conveyor belt – almost like a convoy,” said Bill Patzert, a climatologist to NASA’s Jet Propulsion Laboratory, in a recent conversation with NBC News.

No doubt, California could use some rain. But this much? And, will it help – despite, of course, the floods and mudslides?

Certainly, there’s much more to a drought than simply lack of rain. Sure, it’s a common cause, but there are many other ways to look at drought conditions.

Four kinds of drought

The National Drought Mitigation Center identifies four kinds of drought:

  1. Meteorological – Defined on the basis of dryness in comparison to some “normal” amount of precipitation. Probably the closest definition to “no rain.”
  2. Hydrological – More the bigger picture and a definition that takes into account shortfalls in various sources of water both surface and subsurface.
  3. Agricultural – Here’s where the two definitions above come to bare on the business of growing crops. Maybe there’s not enough water to germinate enough seeds, which leads to lower yield at harvest. Or maybe there’s plenty of moisture to get crops started, but not enough later in the year to keep them growing.
  4. Socioeconomic – Here’s where the effects of drought hinder economic growth. If both supply and demand are increasing, the critical factor is the relative rate of change. Is demand increasing more rapidly than supply? If so, the incidence of such as classification of drought may increase in the future as supply and demand trends converge.

Unfortunately, California has had all four classifications of drought for several years. As a result, even El Nino-sized rains may not be enough to pull the state out of its drought.

Replenishing groundwater

Some parts of California, however, are making plans to bank as much of El Nino’s rainfall as well as other sources of water to put back into the ground.

While rivers, dams and resulting reservoirs get most of the press – after all, a dam like Hoover and a reservoir like Lake Mead are bona-fide tourist attractions – the water we don’t see is just as important as the water we do.

And the water unseen is just as depleted as the water seen.

By last August, 21 state groundwater basins and sub-basins were in “critical” condition. As the drought dragged on, Californians in need of water have increasingly turned to groundwater, digging deeper and deeper wells as other supplies run dry.

In fact, so much water has been pumped out that some parts of the San Joaquin Valley have sunk along with it – as much as 13 inches.

The vast majority of the basins lie beneath the central part of the state, in cities and towns stretching from Bakersfield to Merced, according to the state’s report — the same places where the land is sinking.

The report also pointed to several troubled basins in Southern California. Aquifers beneath parts of Oxnard and Pleasant Valley in Ventura County, the Cuyama Valley near Santa Barbara and the Borrego Valley in San Diego and Imperial counties were on the state’s list.

However, help is underway. Under new groundwater laws passed earlier this year, basins that are identified as critically over-drafted must have sustainability plans in place by 2020. Other basins have an extra two years before they are required to adopt their management plans. Plus, a bond measure passed last year earmarks almost $3 billion for new water storage projects with much of these dollars expected to go toward recharging groundwater.

“A confluence of factors is focusing attention on stowing supplies underground,” according to a recent story in the Los Angeles Times, “which is generally cheaper and less environmentally damaging than building a big dam and reservoir.”

Gallon for gallon, it may also be the best way out of a drought. If all of the state’s reservoirs were filled to the brim, they’d hold 50 million acre-feet of water. (One acre foot is enough to supply two households with water for a year.) But that’s a drop in the bucket compared to the capacity of the state’s groundwater supplies – estimated to hold from 850 million acre-feet on the low side to 1.3 billion acre-feet by the highest estimate, according to California’s State Water Resource’s Board.

What’s more, those bond dollars are likely to create more capacity if spent on additional groundwater storage. According to Stanford University researchers, the bond funding could provide six times more storage if spent on groundwater projects compared to new dams and reservoirs.

Waiting game

Impressive, certainly. But the state is in for a waiting game akin to anyone just waking up, dying for that first cup of coffee and having to wait until the water drips through the filter and into the pot.

No doubt the simplest way to contain water are so-called spreading basins, little more than earthen berms to confine water until it drips into the earth, replenishing groundwater supplies. At its simplest, many of the spreading basins are located with the right type of coarse-grained soil that the water will better pass through and situated to capture rainwater or, more to the point, floodwater that could disappear downstream.

But with the waiting game in mind, officials are also planning to tap into other sources of water, too.

The Orange County Groundwater Replenishment System, for example, takes effluent from a secondary treatment plant and purifies it using a three-step process combining microfiltration; reverse osmosis; and UV light that result in purified water that exceeds all state and federal drinking water standards and has a water quality similar to, or better than, bottled water.

Initially operational at 70 million gallons per day, the system generates enough pure water to meet the needs of 500,000 people. Roughly half of the water is piped to spreading basins in Anaheim.

The Orange County system has been up and running for some time now. But there are other similar plans elsewhere on the drawing board.

Just last month, the Water Replenishment District of Southern California proposed a $95 million water purification plant that they said would help make the district entirely self-reliant on “local” water vs. what Californians term as “imported” water – in most cases, water that comes from the Colorado River, which is also a source of water for other states in the region.

Funding for the facility, which officials hope to break ground on next spring in Pico Rivera, is to come, in part, from the almost $3 billion source we mentioned earlier.

The treatment facility would operate on much the same filtration procedure as the Orange County plant. What’s more, the proposed facility is key to the area’s plans to replenish groundwater. The district manages two underground aquifers that provide water to roughly 40 percent of the population of southern Los Angeles County.

The district currently recharges the aquifers with a mix of treated sewage water from the Sanitation Districts of Los Angeles County, storm water runoff and imported water purchased through the Metropolitan Water District and State Water Project.

Current regulations, however, cap the amount of treated sewage water that the district can use for replenishment so it relies more on runoff and some 21,000 acre-feet of imported water annually. But by using the purposed plant to purify locally treated sewage water, the district hopes to stop the purchase of imported water.

The plan not only conserves water, but also saves money. An acre-foot of imported water currently costs more than $1,000 compared with treated sewage water for less than $200 per acre-foot. In other words, whether it’s purifying water or capturing more rain, the state’s trying its best to step in for Mother Nature. 

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