The 'Miracle March' storms have reduced the severity of drought in California. The most significant is a 10 percent decline in severe drought.
But reservoir levels did not improve in many parts of the state and groundwater has not recovered after years of drought.
"A westerly flow of Pacific weather systems pummeled the west coast this week, bringing much-needed rain and snow to northern California and the Pacific Northwest and improving the drought situation," according to the U.S. Drought Monitor report released March 17.
Last week, the report said California was "primed for drought improvement."
And, this week's report (which has a cutoff of Tuesday at 5 a.m. PDT) reflects that improvement, the first significant reductions in the percentage of drought this winter.
The Drought Monitor drought intensity levels are Abnormally Dry, Moderate, Severe, Extreme and Exceptional.
In California, 99 percent remains abnormally dry, no change from the previous week.
But moderate drought was reduced from 97 to 93 percent, and severe drought, 83 percent last week, is now at 73 percent, a 10 percent improvement.
Other levels of drought were also reduced: Extreme drought covers 56 percent of California and exceptional drought is now at 34 percent.
"The precipitation fell as rain at the lower elevations, with 1 to 2 feet of new snow measured at the higher-elevation SNOTEL sites in the Cascades and parts of the Sierra Nevada," says the weekly update. "Mountain snowpack was near to above average at most of the high elevation sites across the Far West."
The report cautioned that the average-to-above-average rain and snow won’t erase years of drought in California.
"While it improved mountain snowpack and reservoir levels, significant precipitation deficits remained across California from the state’s 4 to 5 year drought," the update notes.
And, while "drought intensity reductions were seen in northern to central California and along the coast, and reservoir levels were restored to average for this date," other reservoirs are below average.
"But most of the other California Department of Water Resources reservoirs were still below-average, including Trinity Lake in the north (at 61% of average as of March 17)," according to the report.
"The surface soils were saturated due to the recent rains, but the deeper groundwater levels had not recovered. Wells were still going dry in Tuolumne County and deficits continued in groundwater and reservoir levels supplying areas such as San Joaquin County."
The DWR March 16 statistics showed mountain snowpack snow water content at 101 percent of the April 1 average in the Northern Sierra, 92 percent in the Central Sierra, and 77 percent in the Southern Sierra.
"With a near to below-normal mountain snowpack, streamflow is expected to be near to below normal during this summer at current projections," according to the update.
In Nevada, exceptional drought was removed from western Nevada east of Lake Tahoe in Washoe, Storey, Carson City, Lyon, and Douglas Counties.
"Even though this area was in a rain shadow and didn't benefit much from the systems of the last 2 weeks as did California, the area shows up as wet at 6-24 months, is benefiting from the above-normal SWE in the Sierra Nevada to the west, and has improved water supply along the Truckee and Carson rivers," the Drought Monitor reports.
The U.S. Seasonal Drought Outlook (released March 17) shows "drought persisting" in southern, central and much of northern California and western Nevada, with some "drought removal likely" in extreme northwest California.