Hydrologic Extremes

The USGS closely monitors the effects of drought through data collection and research. USGS science supports water managers in preparing for possible future drought by providing information that takes into account 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...

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 USGS California Water Science Center maintains nearly 500 streamgages that collect data to determine the amount of water flowing in rivers and streams, and in and out of reservoirs, in California. Automatic alerts are...

Over the last several decades, both the incidence of large wildfires and the duration of the wildfire season across much of the United States have increased (Westerling and others, 2006, American Water Works Assn, 2008; Finco and others, 2012). Future wildfire projections based on forecasted climate scenarios indicate both an increase in the expected severity of wildfires, and an expansion of...

Drought is making the Delta Saltier. Less freshwater coming from watershed runoff and reservoir releases means that more salty water flows into the Sacramento San Joaquin Delta (Delta) from the Pacific Ocean. Changes in Delta salinity have far-reaching impacts, affecting the water supply for agriculture, drinking, wildlife, and Delta ecosystems.

An operational model for Salinas Valley is needed to evaluate and compare ecosystem, conservation, and water demands. This model must simulate current operations, assess benefits of and evaluate scenarios for tunnel operation and potential reservoir and spillway modifications.

Soil moisture is a critical variable for understanding the impacts of drought on ecological, hydrological, and agricultural systems, as soil moisture content has a direct affect on runoff amounts. Runoff occurs as the result of precipitation (both rainfall and snowfall) that is in excess of the demands of evaporation from land surfaces, transpiration from vegetation, and infiltration into soils...

In California, drought and warmer climates have increased the prevalence, severity, and duration of wildfires. These fires have destroyed over 129 million trees. In the aftermath of this devastation, there is heightened urgency to increase the capacity of seedling production, particularly for the lower-elevation and private lands that CAL FIRE is responsible to help manage. To support CAL FIRE in...

As a result of climate change, heavy rainfall, as well as extended dry periods, are becoming more common in the Midwestern United States. These trends are only expected to continue. So, increasing the capacity of soil to store water has become more critical. Storing water increases availability in dry conditions. And the absorption of additional water in wet conditions reduces potential flooding...

The frequency of fire in southern California forests has steadily increased over time as a result of ignitions at the growing wildland-urban interface, as well as a result of warming due to climate change. Understanding the implications of increased wildfire on hydrologic conditions and water supply is particularly important given the increasing demands for water resources to satisfy growing...

Because the following information has immediate and time-sensitive relevance to public health and welfare owing to the Governor's declared drought emergency it is being released as preliminary information. As preliminary information, it had been reviewed and approved to meet the needs for timely best science, but the methodology is subject to refinement. The information is provided on the...

Plant distributions at local to global scales are influenced by the interplay among plant traits (physiology, anatomy, morphology), the physical setting, biotic interactions, and historical factors such as disturbances and responses to past climate change. Physiological strategies and functional traits provide a key starting point to understand how distributions are shaped along gradients of...

The North Coast Resource Partnership (NCRP) is an innovative, stakeholder-driven collaboration among local government, Tribes, watershed groups, and interested partners in the North Coast region of California. The North Coast comprises seven counties, Tribal lands, major watersheds, and a planning area of 19,390 square miles representing 12% of California's landscape. The NCRP integrates long-term...