- Models indicate that rain and snowfall will become even less predictable in California, likely with more precipitation falling as rain rather than snow.
The Department of Water Resources marks a new water year by reminding Californians of the importance of making water conservation a way of life. Water Year 2012-13 officially begins Oct. 1, 2012 and runs through Sept. 30, 2013.
Water Year 2011-12 now goes down on record as the first “dry” year since the 2007-09 drought.
But early weather forecasts for this winter are split and suggest that this year’s weather is anyone’s guess.
Conservation is the consistent, year-to-year message in drought-prone California, where wet winters often are followedby dry periods that draw down storage reservoirs.
“We must always look beyond the current year, whether it turns out wet or dry,” said DWR Director Mark Cowin. “We are working toward more reliable water deliveries through the Bay Delta Conservation Plan, but household and backyard conservation will always be a way of life in California.”
If anything, the uncertain effects of climate change reinforce the conservation message.
Models indicate that rain and snowfall will become even less predictable in California, likely with more precipitation falling as rain rather than snow. This may require increased storage to capture rainwater, which runs rapidly into streams and reservoirs, whereas mountain snow melts slowly through spring and early summer.
“It is becoming clearer every day that we need to increase the flexibility and adaptability of our statewide storage and delivery systems,” said Cowin.
The start of the water year — coinciding with the beginning of the rainy season — is significant to water watchers at DWR and other agencies.
Throughout each water year, DWR hydrologists and meteorologists measure precipitation and runoff in the Northern Sierra and other key watersheds and produce runoff forecasts. Measurements are taken by gages in major rivers, including the Sacramento, Feather, Yuba and American. And DWR snow surveyors will don skis on or about the first of January to begin their winter measurements of water content in the mountain snowpack that normally provides about a third of the water we use in California.
All this information goes into forecasts of water supply for spring and summer, the heaviest months of water use by farms and communities.
In spite of relatively dry conditions in 2011-12, DWR was able to deliver 60 percent of requested State Water Project water, thanks to reservoir storage largely carried over from the previous wet year. However, should the new water year beginning Oct. 1 also be dry, the state’s reservoirs and groundwater basins will have less carryover storage for the following year.
For further information about California’s water conditions, visit http://www.water.ca.gov/waterconditions/.