a few showery days, and 6-12" of snow (2-3" water equivalent) aren't going to cut it. Estimates are we'd need another 20-30" of liquid (upwards of 20-30 FEET of snow) by April 1st to reach average runoff. That gets less and less probable with each passing day. But January will not be near a record, at least.Bottom Line: Supply is NOT going to be there for us. How are we doing on managing demand? Pretty bad. There's talk of rationing (which is terribly harmful to business and lifestyles) but hardly any mention of conservation pricing. Be sure to congratulate the water managers for creating the "shortage."
The Northern Sierra 8-Station Index is a relatively obscure figure that tells a great deal about water supply... It's a measurement of total precipitation over key watersheds; the Upper Sacramento, Feather, Yuba and American. The eight sites basically translate to forecast inflow for Shasta, Oroville, Folsom, New Bullards Bar, Englebright Reservoirs, etc. None of those reservoirs are in great shape... Anyway, the precipitation is measured as liquid, in the sense that whether it's rain or snow, eventually it will make it into the watershed. Of course, the ground itself absorbs a lot of that; moreso as drought conditions worsen.
The 8-Station is currently at 17.8" for the season. The average since 1920 is 50" per year (running from October 1 - September 30). So, we'd need 32" inches of rain/snow/liquid, however you want that to fall, over the next 3 months for an average year. (And average precip doesn't necessarily mean average runoff.) The normal amount for the remaining months of the season is 23"... The next 9 days over the Feather River Basin will be dry. No more in the bucket for January. Plus there was a total 28" deficit over the last two seasons, don't forget. A 3rd dry year is underway.
28 Jan 2009
Sparse Rain and Bad Management
The Weather and Climate Newsletter from California's Department of Water Resources has the bad news: