Hydrologic Extremes

To create a framework for adapting to climate change, decision makers need to understand specific threats to our water supply, land use suitability, hazard risks, ecosystems and quality of life. A vulnerability assessment that defines the projected degree to which an ecosystem, landscape, or watershed is vulnerable to change will help to create this framework. Presently those who are open to...

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...

Groundwater has been the primary source of domestic, agricultural, and municipal water supplies in the southwestern Mojave Desert, California, since the early 1900s. The population of the Mojave River and Morongo groundwater basins has grown rapidly during the last several decades, increasing from an estimated population of almost 273,000 in 1990 (Mojave Water Agency, 2004) to more than 453,000 in...

The endeavor to ensure a viable population of the threatened wolverine to the mountains of California requires the characterization of suitable habitat.

Interferometric Synthetic Aperture Radar (InSAR) is an effective way to measure changes in land surface altitude. InSAR makes high-density measurements over large areas by using radar signals from Earth-orbiting satellites to measure changes in land-surface altitude at high degrees of measurement resolution and spatial detail ( Galloway and others, 2000 ). Synthetic Aperture Radar (SAR) imagery is...

The Sonoma County Water Agency (SCWA) and the San Francisco District office of the U.S. Army Corps of Engineers (CORPS) have identified issues associated with sedimentation in the lower Laguna de Santa Rosa and Mark West Creek in Sonoma County. Human activities in the watershed over the last 200 years have accelerated erosion and sediment delivery to the Laguna reducing the water storage capacity...

Throughout the late 1800s and into the 1920s when two thirds of the Santa Clara Valley had been irrigated, water flowed freely from wells. Water-level declines of more than 200 ft occurred in the Santa Clara Valley from the early 1900's to the mid 1960's (Fowler, 1981). Land subsidence was first detected in 1933 (Poland and Ireland, 1988). As the decades passed, groundwater levels continued to...

The Sacramento-San Joaquin Delta is part of the San Francisco Estuary, home to a diverse flora and fauna, including several threatened and endangered species, has a large area of prime farmland, and serves as the hub of California's freshwater-delivery system that moves water from the wet north to the dry southern part of the State.

The Laguna de Santa Rosa, located in Sonoma County, California, flows into Mark West Creek, which drains into the Russian River. The Laguna-Mark West drainage is the largest drainage contributing to the Russian River, encompassing approximately 21% of the total Russian River basin. Runoff from precipitation in headwater areas enters fast-flowing creeks that transport water and sediment downstream...

Groundwater flow model of the Santa Clara Valley.

Understanding the magnitude and variability of baseline greenhouse gas (GHG) emissions from the Sacramento – San Joaquin Bay Delta is critical for current and future land management. For example, strategies that maximize carbon sequestration in soils and plants while minimizing unintended consequences such as GHG emissions are likely to produce both economic and environmental benefits for the...