The next six weeks will determine the severity of California’s fourth year of drought.
After an unusually wet December, the heavens have gone dry so far in January.
“The next six weeks are critical,” noted South San Joaquin Irrigation District General Manager Jeff Shields.
While “the numbers are still trending favorable” for SSJID and Oakdale Irrigation District for 2015 water supplies based on superior water rights and contractual water rights, the same is not true for most of California.
New Melones Reservoir — the state’s fourth largest reservoir — in Tuolumne and Calaveras counties was at 550,000 acre feet on Monday out of a 2.1 million acre feet capacity. Last year at the same time it was at 1,050,000 acre feet. In a normal year the water level on Jan. 12 would be at 1.4 million acre feet.
“The last three summers have basically depleted the cushion that New Melones had,” Shields noted.
The SSJID and OID have rights to the first 600,000 acre feet of water that flows into New Melones after the start of the weather year on Oct. 1. As things stand now, that level of inflow will be reached. However, since other areas of California will be looking for water SSJID officials have repeatedly noted that conservation must never stop being a priority even if the district gets all of its water since other areas will be looking to purchase what they can. At the same time, the district needs to consider the possibility of a fifth drought year and building up a carryover reserve.
The outlook calls for a chance of two showers before month’s end. As things stand now the forecast for February calls for as many as 12 days of rain.
“The forecast is for a wet February, but remember it is only a forecast,” Shields said. “Traditionally, we get most of our rain in January, February and March. We’ve got a long way to go before we are OK.”
Critical for the statewide outlook is the Sierra snowpack. More than 60 percent of California’s developed water supply originates in the Sierra either in the form of snow or rain.
Data shows the Sierra snowpack water content is currently at 50 percent of normal. That is, however, a significant improvement from last year in January when it was at 20 percent of normal.
December in terms of precipitation was good for SSJID and OID at Beardsley Reservoir that serves as the first of a series of reservoirs the two agencies operate as partners in the Tri-Dam Project on the Stanislaus River watershed.
Beardsley received 7.25 inches of rain or 150 percent of the normal 5.85 inches for December. Since the state of the water year on Oct. 1, Beardsley has received 11.2 inches as of Jan. 11 or 88 percent of the normal 12.72 inches. Last year in the same time period Beardsley received only 3.58 inches of rain.