It's great to see snow again in the Sierra Nevada. It's one of the beautiful scenes this time of year from the UC Merced campus, the bright white of new snow in the mountains where our group conducts research to help the Central Valley and California achieve a sustainable water supply.
With better management, our state's snow and rain could go a lot further to meet our urban and agricultural uses. This is especially important as climate warming puts additional stress on supplies.
The state critically needs an updated water information system, which is feasible using low-cost technology developed at UC Merced and other California universities.
Partnerships with the California Department of Water Resources and other key stakeholders such as our irrigation districts, resource management agencies, utilities and farmers would make the system truly unified and beneficial to everyone.
Almost all operations of California's hydropower and other reservoirs are controlled using forecasts based on historical snowpack and runoff data. But in the face of global climate change and growing water demands, these forecasts are increasingly inadequate to manage the state's water resources. For California's Sierra Nevada, climate warming means a shift from snow to rain, more intense rain storms and more year-to-year variability, including droughts.
Relatively small investments in satellite and aircraft remote- sensing data, ground-based measurements and information systems can reduce uncertainty about water availability.
At the multicampus UC Center for Information Technology Research in the Interest of Society we have developed the core elements of a real-time intelligent water information system. Our first prototype was built in the Southern Sierra Critical Zone Observatory, southeast of Shaver Lake. The value of our technology has been demonstrated over the five years since starting that project.
It is now time to think big and join forces to accurately map the entire Sierra Nevada water cycle, including snowpack and daily snowmelt, temperature, relative humidity, precipitation falling as rain or snow, solar radiation, soil moisture, evaporation and water use by vegetation, groundwater and runoff.
The Department of Water Resources has initiated some of the pieces needed for a new water-information system, and is working with NASA to get better estimates of snow-covered area and data that will help us estimate snowpack water content.
Together, this information provides accurate estimates of how much water these areas will yield. The state's water scientists and other water managers are prepared to use forecasting systems that rely on better data such as that from sensors we're now installing in the American River basin in Placer and El Dorado counties.
Our goal should be to reduce prediction errors by at least 50 percent. We can produce this improvement by investing in thousands of low-cost, reliable sensors over hundreds of square miles in the Sierra, from the Sacramento and Feather River basins to the Kern River.
These low-power wireless sensors are aggregated to a network manager, with decisions made based on a lot more, and better, information than is available today. As my CITRIS co-developer Steve Glaser points out, "The most critical element will be the cyber infrastructure that links this network together, and it must be flexible to provide a variety of access for automated and directly linked human decision makers."
Judging from conversations with water managers and users alike, the value to California of halving uncertainty in water forecasts and upgrading our systems to adapt to climate change is really a no-brainer.
I know we are fond of seeing the dedicated snow surveyors going out with their long tubes to measure the snowpack. It is simple to understand, and even with an updated and automated water-information system we'll still need some manual measurements.
But if we invest in better data and analysis, everyone in California will benefit and we'll move toward a sustainable, more-secure water supply for the Central Valley, too.
Bales is a professor of engineering and director of the Sierra Nevada Research Institute at UC Merced.
UC Merced helping to developbetter ways to manage state's water