California looks to be resuscitated this spring, with green stretching the length of the state and the desert erupting in a colorful mosaic fueled by a super bloom of flowers. The state’s wet winter has erased a surface drought more than five years in the making. Now, many reservoirs have been topped off, rivers are running and the snowpack – so meager just two years ago as to be almost unmeasurable – is piled 50ft (15m) high in some places.
Officially, the state’s emergency drought regulations are still in place, but that’s likely to change soon as Gov. Jerry Brown said he wanted to wait until the end of the rainy season. It’s unclear yet whether the governor will revoke all or just parts of the regulations.
After deluges swamped California in January, inducing flood emergencies, water agencies began petitioning the state to end the drought emergency orders. In late January, San Diego County Water Authority’s board voted to “declare an end to drought conditions in the region.”
The State Water Resources Control Board voted at the beginning of February to extend water conservation requirements, despite protests from water suppliers that it sent mixed messages to consumers to conserve during a time of seeming abundance.
Now, at the beginning of April, California officials seem poised to begin dismantling drought emergency provisions while at the same time continuing to build a long-term plan for water conservation and efficiency in a state where the next drought could be just around the corner.
To better understand the current water picture in California, it helps to compare where we were last year to where we are today.
At the end of March last year, the U.S. Drought Monitor showed 90 percent of the state in drought, including half in either extreme or exceptional drought, the two most severe designations. Now only 8 percent of the state is experiencing some form of drought and no areas are in extreme or exceptional drought.
So what happened? A lot of precipitation. In most of the state, precipitation totals for the water year (which began in October) are nearing twice the average on April 4 (198 percent of average in the northern Sierra, 190 percent in the central Sierra and 176 percent in the southern Sierra).
The northern Sierra region is inching toward the wettest year in recorded history and another atmospheric river is predicted to hit the state later this week, which could tip the scales.
This has meant that many of the state’s reservoirs have refilled; some have been spilling water for flood control.
A look at some of the state’s biggest reservoirs paints a rosy water supply picture, although the wet winter has presented other challenges, including dangerous flood conditions at Lake Oroville after problems at its spillway and emergency spillway caused the evacuation of nearly 200,000 downstream residents, racking up $100 million in repair bills.
California’s biggest “reservoir,” its snowpack, which stores about one-third of the state’s water, recorded a key reading on March 30. The monthly snowpack measurement that occurs on (or near) April 1 is considered the peak snowpack figure for the year, and an important tool in assessing the year’s bounty.
The March 30 reading found the statewide average across the Sierra at 164 percent of the historical average for this time of year.
State climatologist Michael Anderson said, “Although the record pace of the snowpack accumulation fell off significantly in March, California enters the snowmelt season with a large snowpack that will result in high water in many rivers through the spring.”
Los Angeles has already declared a state of emergency to cope with the high runoff expected from the eastern Sierra Nevada as the snowpack melts in the Owens Valley region, the headwaters for an aqueduct that sends water 200 miles (320km) south to the city.
Flooding concerns are mounting again, with more wet weather expected this week, but the risks are a tradeoff many water managers are willing to take in exchange for the water they received this year, said Jon Ericson, chief of hydrology and flood operations for California.
The short-term picture for California’s water this year is good, but long-term concerns remain as some communities still face dry wells and the state has a large groundwater debt. Overpumping of groundwater has caused the ground to sink as much as 28ft (8.5m) in parts of the the San Joaquin Valley since the 1920s, NASA reported.
A report provided to California’s Department of Water Resources by NASA’s Jet Propulsion Laboratory in February showed land subsidence near critical water infrastructure measured by satellite from May 7, 2015, to September 10, 2016.
The report found the ground sinking as much as 2ft (60cm) a year in some places due to groundwater pumping. “While we can see the effect that rain has on subsidence, we know that we’ve run a groundwater deficit for some time, so it’ll take a long time to refill those reservoirs,” said JPL report coauthor Tom Farr.
Groundwater overdraft is not the only long-term water issue for the state to deal with; climate change will also alter the amount and timing of snowpack in the decades ahead.
This year’s swing from drought to flood was an important test of the state’s readiness to deal with climate extremes, which we can expect more of in the future.
“We got a wake-up call that although we have a lot of climate science and a lot of information that has told us to expect more extreme conditions, our management systems and our infrastructure hasn’t kept pace with the new normal, and clearly evacuating 200,000 people [because of the Oroville dam emergency] is not going to be a success in anyone’s book,” said climate scientist Juliet Christian Smith of the Union of Concerned Scientists.
“We’ve made some decisions about planning for the future with using the past as our guide and that clearly can’t continue because that risks human health and safety.”
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