Avariety of technologies aid this work, including airborne electromagnetic surveys to monitor and map groundwater and those that help predict and prepare for future drought periods.
Already this year, the State Water Project forecasted allocation for 2023 is 75 percent of requested supplies — up from recent years — for the 29 state water contractors. A final allocation will likely be announced in May.
As explained by State Water Project water operations manager Molly White in an email to Government Technology, DWR operates the State Water Project to help manage the water supply for 27 million people and 750,000 acres of farmland. The central goals are to make sure adequate water supply is available to those who need it and to reduce flood risk.
“DWR’s Water Operations team plans and monitors system conditions, such as hydrology, water quality and flows, and storage levels from Lake Oroville in the north to Lake Perris in the south and makes real-time changes in operations to comply with environmental regulations, ensure public safety with flood control releases, maximize water deliveries, and plan for future water supply uncertainties,” she explained.
The state has also seen historically high snowpack this year. The agency analyzes snowpack data with a focus on both albedo — or reflectiveness — and temperature to establish an estimated timeline on melt. These factors, along with depth and water content, help the agency better understand how snowpack will translate into runoff and when, David Rizzardo, manager of DWR’s hydrology branch wrote in a response to Government Technology.
Rizzardo explained that DWR’s Division of Flood Management’s Snow Surveys and Water Supply Forecasting Unit contracts with Airborne Snow Observatories Inc., a company that uses lidar and spectrometer technology to measure snowpack. Lidar data collection flights occur over the watershed during late summer and fall when there is no snow on the ground. In the winter and spring, these flights occur over existing snowpack, calculating snow depth by comparing with the data from the summer collection.
“This process collects volumes of additional data, far more than what individual snow sensors or snow surveys can tell us at one or a few dozen locations,” Rizzardo explained.
Data from airborne snow surveys, modeling, and weather and hydrological forecasts, paired with tools available through DWR’s partnerships with academic institutions, helps to provide water managers with the information they need to adapt their water management plans as they face down California’s “new climate realities” and the often dramatic swings between dry and wet conditions, Rizzardo said.
Groundwater data, meanwhile, is collected through airborne electromagnetic (AEM) surveys to help local agency managers make informed decisions, Steven Springhorn, technical assistance section manager within the Sustainable Groundwater Management Office, explained in an email. Those measurements actually gather information about aquifer structure rather than groundwater levels. Therefore, high levels of snowfall and rain this year will not affect the data itself, though wet and dry conditions do play a role in groundwater use.
“Generally, water users rely less on groundwater in wet years — when surface water is more abundant like this year — and more in dry years like the past three years of drought,” he explained. “In some smaller and more vulnerable communities that lack access to surface water, groundwater provides up to 100 percent of drinking water supplies."
Springhorn noted that high levels of snowfall and precipitation have highlighted the value tech brings to understanding groundwater recharge areas. This increased awareness has led the state to expedite AEM data use and launch a groundwater recharge-focused pilot study, launching in spring 2023 and running through summer and fall 2023. DWR and other groundwater monitoring entities will continue to collect data and make it publicly available.
“The pilot study goals are to locate fast-track groundwater recharge pathways and better define groundwater recharge sites so that locals have improved information about groundwater recharge locations and practices,” he said.
All of these methods also pair with several other major DWR efforts, Rizzardo said, underlining how partnerships with other entities — such as the Scripps Institution of Oceanography’s Center for Western Weather and Water Extremes and the National Center for Atmospheric Research — expand DWR’s ability to access data that can further inform this water management work.
