The odds are increasing that winter storms associated with El Niño are having a significant impact on California’s historic drought. The question is whether it will be enough to modify water restrictions or possibly even lower the drought severity.
Uncertainty of just how much of an impact the storms had, or will have as winter progresses, will likely linger into spring, according to Jay Lund, Director of the Center for Watershed Sciences at UC Davis.
Despite steady rain and snow over the past several weeks, many areas in California are still below normal for precipitation and snow for the current water year, which began Oct. 1.
“Unless we get a really big flood, we won’t really know the drought condition until about April 1, roughly the end of the wet season,” Lund said.
The recovery process will be slow and additional storms are needed through the rest of winter to accurately gauge progress.
Regardless, the early winter returns have been encouraging.
“The rains/snow have helped quite a bit,” said Associate Geoscientist/Climatologist Brian Fuchs of the National Drought Mitigation Center (NDMC). “After 3-4 years of drought in the state, the beginning to this water year has been very favorable. The soils have seen moisture replenished in the top layers and some run-off has been captured in the reservoir network. There is good momentum for the rest of winter, meaning that if the wetter than normal pattern continues we will see improvements to the state as the impacts diminish.”
Fuchs agreed that a substantial amount of rain and snow is still needed to put a considerable dent in the drought.
“Not all of California has seen above normal precipitation for the current water year,” he said. “It will be very difficult to eliminate a multi-year drought in one season, but there is a good opportunity to put a big dent in it, meaning we should anticipate seeing the current drought conditions ease this year.”
The California Department of Water Resources and the U.S. Bureau of Reclamation finalized the 2016 Drought Contingency Plan on Jan. 19 that outlines State Water Project and Central Valley Project operations for February through November 2016.
The plan focuses on water project operations as related to the potential modification requests needed to balance the competing needs and benefits of limited water supplies due to the state’s four-year drought.
Read the full contingency plan here.
“As the full extent of the run-off forecasts are realized closer to spring, each water system should have the opportunity to evaluate their situation and needs based upon current and anticipated storage,” Fuchs said. “Some may be able to rescind restrictions, while others may linger on as the systems fully recover. I believe that there is optimism for improvements, but I also caution that until the situation warrants improvements, we should hastily arrive there.
“Conservation is always a good message, even in wetter times,” he added. “As we have seen many times during the past four years, very favorable wet periods abruptly ended and impacts did not go away.”
The NDMC released updated drought maps today, with 69.07 percent of California still in D3-D4 drought, lumping these same areas in D2, D1, and D0 at the same time. D4 is considered an exceptional drought, while D3 is extreme drought. D2 is severe, D1 is moderate and DO is abnormally dry.
Although another weather system is expected to arrive Friday and extend into the weekend across California, some cities could experience 10 degrees above-average temperatures next week.
In new data released by NASA and the National Oceanic and Atmospheric Administration (NOAA), 2015 was Earth’s hottest year on record. Land and ocean temperatures were nearly two degrees above average.
“My guess is that 2016 will be better than 2015, but it is still early days with more than half of the wet season to go,” said Lund. “It could still go either way, but if I had to wager, I’d guess it will be better than last year.”
The drought was effectively declared a State of Emergency by Governor Edmund G. Brown Jr. on Jan. 17, 2014.