Surface Water Supply

The USGS closely monitors the occurence and effects of drought through data collection and research. USGS science supports water managers in preparing for possible future drought by providing information about long-term hydrologic, climatic, and environmental changes. These studies support successful planning and science-based decision-making by water managers who must address complex issues and...

Throughout the nation, the USGS operates a streamgage network in near real-time that helps emergency managers and others protect life and property due to floods and other water-related hazards. The USGS California Water Science Center maintains nearly 500 streamgages that provides key streamflow and water level data for flood forecasters, the public, and emergency managers at the federal, state...

The USGS is collecting continuous and discrete monitoring data to document baseline conditions and physical responses in downstream river reaches before, during, and after dam removal. These monitoring data will be integral for post-removal assessments and collaborations with basin partners.

Blue carbon ecosystems (BCEs) are coastal ecosystems, such as tidal marshes, mangroves, and seagrasses, with manageable and atmospherically significant carbon stocks and fluxes. The tidal marshes and scrub-shrub wetlands in the Sacramento-San Joaquin Delta (Delta) of California are examples of BCEs. The Delta is a 2,400 square kilometer tidal freshwater region located at the landward end of the...

Drought, along with recent wildfires, have had enormous impacts downstream on water quantity and quality. These conditions have greatly impacted the agriculture and the residents of the nearby Central Valley.

The USGS seeks to increase understanding of the groundwater system in the vicinity of the Lower Colorado Water Supply Project well field and to estimate future groundwater levels and total dissolved solids concentrations in the wells and the long-term viability of the Lower Colorado Water Supply Project.

The San Francisco Bay and Sacramento-San Joaquin Delta form one of the largest estuaries in the United States. Water flow and water quality in the San Francisco Bay-Delta Estuary are important to the economies of both California and the nation. The Bay-Delta system provides water to more than 25 million California residents and vast farmlands, as well as key habitat for birds, fish, and other...

The MODFLOW One-Water Hydrologic Flow Model (MF-OWHM) – Conjunctive Use Simulation Software (Boyce, 2022; Boyce and others, 2020; Hanson and others, 2014) builds upon the MODFLOW-2005 framework for the simulation and analyses of conjunctive-use, water-management, and climate-crop-water scenario problems.

The Pajaro Valley is home to a billion-dollar agricultural industry, providing food and food processing services for the nation. The water for these enterprises is supplied, in large part, by the groundwater resources (aquifers) in the area. The Pajaro Valley Water Management Agency (PV Water) and the USGS have partnered to improve aquifer monitoring software, allowing better quantification and...

Drought in the Russian River region is keyed to the absence of large winter storms-the RR is winter rain-driven, with a few atmospheric river (AR) storms each year bringing 40-50% of the annual rainfall. Two multi-purpose reservoirs provide storage for warm-season uses, and there is little to no snow pack to extend the runoff season. The same ARs that provide beneficial water supply can also cause...

To help emergency managers and others protect life and property due to floods and other water-related hazards, the USGS delivers a continuous source of streamflow information. The U.S. Geological Survey has been measuring streamflow in the U.S. for over 120 years. We operate more than 7,500 streamgages in the U.S. and nearly 500 in California that collect data to determine the amount of water...

The Russian River Watershed covers 1,500 square miles of urban, agricultural and forested lands in northern Sonoma County and southern Mendocino County, California. Communities in the Russian River Watershed (RRW) depend on a combination of Russian River water and groundwater to meet their water-supply demands. Water is used primarily for agricultural irrigation, municipal and private wells supply...