Growers up and down the state were celebrating an abundance of rainy days during the first two weeks in December, which had many people hoping the end of the three-year drought was near.
Even the chief hydrologist for the California Department of Water Resources, Maury Roos, was quoted on Monday, Dec. 15, that he was “kind of optimistic” that the drought would end this year. Unfortunately, a wet month does not necessarily mean the end of the drought.
Doug Carlson, an information officer at DWR, said that while the double digits of precipitation in early December was a very good start, “one need only look at December of 2012” to be brought back down to earth. Several years ago, the average rainfall at eight Northern Sierra stations that serve as the gauge for the area was at about 23 inches by mid-December, which was well above normal. The next six and half months didn’t equal that amount of precipitation and totals for the year was still below normal.
After our heavy early-December storms this year, those eight measuring sticks came in at near 20 inches mid-month. That’s a very good number and much better than the last couple of years, but still does not signal that the state is out of the woods. As Carlson spoke to WG&S on Dec. 15, another storm was pelting California, and still another was due by the end of the week. “It’s very good news. For the Northern Sierras, as of 9 a.m. today (Dec. 15) we are 139 percent above average and the rain is still falling right now.”
It is a foregone conclusion that the state will move into the new year with much more rainfall under its belt than a year ago. Carlson said the reservoirs have been able to capture a good deal of the runoff and things are definitely looking up. For example, the Oroville reservoir, which is one of the largest in the state, reached its low point on Nov. 21 with a total of 898,221 acre feet in storage. By Dec. 14, the lake held 1,143,195 acre feet, a gain of almost a quarter of a million acre feet in three weeks. That’s a tremendous gain, and if it can be duplicated over the next three weeks or even a month, that would be great.
Unfortunately, Carlson said one cannot make assumptions about the winter based on a few weeks of storms. But he said the “ridiculously resilient ridge,” as many have called the high-pressure system that has sat off the California coast for the past couple of years, is no longer there as of mid-December. For the past three years, this ridge has pushed storms north of California as they came from the ocean and hit land. The ridge has been credited with California’s drought conditions as well as frigid temperatures in the Midwest and East.
But as of mid-December, the ridge was gone and a more normal storm pattern was upon us. “What we have seen so far this year is not typical of the last two years,” said Carlson. “Last year (around this time of year) we had 57 straight days without rain in the Sacramento area. We appear to be following a more normal pattern this year.”
In fact, many areas of Northern California — including Redding, Santa Rosa, San Francisco, Oakland and San Jose — had already reached 50 percent of their normal annual precipitation by mid-December. San Diego was at 40 percent though the San Joaquin Valley was still below 35 percent.
Carlson said the storms that were approaching later during the week of Dec. 15 were colder weather events and snow was expected at the higher elevations. In fact, it is possible that by the time this story is being read in early January, the state’s water picture could look even rosier. One thing these early storms are probably doing is giving the state the opportunity to have a normal precipitation year without a miracle month late in the season.
However, reservoirs are relatively empty and it will take more than one year to fill most of them. Folsom Lake could be filled in a year, but it’s going to take at least two above average years to get Lake Shasta back to a normal level.