Second Supplement to State Water Resources Board Bulletin No. 11, San Joaquin County Investigation, Basic Data, Calaveras Unit, 1955-56

California Department of Water Resources (DWR) | April 20th, 1957

Securing Color River Supplies - An Urban-Agriculture Partnership in the Palo Verde Valley

Metropolitan Water District of Southern California (MWD) | March 16th, 2022

Sensitivity of Mountain Hydroclimate Simulations in Variable-Resolution CESM to Microphysics and Horizontal Resolution

American Geophysical Union (AGU) | July 31st, 2018

Severe Sustained Drought Revisited: Managing the Colorado River System in Times of Water Shortage 25 Years Later — Part I

American Water Resources Association (AWRA) | September 20th, 2022

SGMA Alternative Groundwater Sustainability Plan Bridge Document for the Indio Subbasin

Coachella Valley Water District (CVWD) | December 29th, 2016

SGMA Alternative Groundwater Sustainability Plan Bridge Document for the Mission Creek Subbasin

Coachella Valley Water District (CVWD) | December 29th, 2016

Sierra Nevada Regional Report - California’s Fourth Climate Change Assessment

California Natural Resources Agency (CNRA) | August 16th, 2018

The Sierra Nevada region is critical to the environment and economy of California. Its places and peoples provide essential natural resources including fresh wate

The Sierra Nevada region is critical to the environment and economy of California. Its places and peoples provide essential natural resources including fresh water, clean power, working lands, and famous wilderness. The region encompasses tremendous geographical, climatological, and ecological diversity that spans majestic mountains to deep desert basins. The climate consists of cool, wet winters and warm, dry summers with large differences due to latitude (e.g., the southern Sierra is snowier than northern Sierra) and topography (e.g., the Westside is wetter than the Eastside). Variability is another notable feature of the climate with the region experiencing some of the largest year-to-year climatic fluctuations in the United States. Herein we summarize our assessment of climate-change vulnerabilities and adaptation actions in the region.

Simulated Effects of Ground-Water Management Alternatives for the Salinas Valley, California

U.S. Geological Survey (USGS) | December 15th, 1988

A two-dimensional digital ground-water flow model was developed to analyze the geohydrology of the ground-water basin in the Salinas Valley. The ground-water model was ca

A two-dimensional digital ground-water flow model was developed to analyze the geohydrology of the ground-water basin in the Salinas Valley. The ground-water model was calibrated for steady-state and transient simulations by comparing simulated with measured or estimated inflows, outflows, and water levels for 1970-81. Preliminary estimates of hydraulic properties and some inflows and outflows were adjusted during model calibration. The simulated mean annual water budget for the basin was 559,500 acre-feet per year each of outflow and inflow. Inflow components consisted of Salinas River recharge (38.3 percent), percolation of irrigation water (34.0 percent), small stream and Arroyo Seco recharge (20.9 percent), seawater intrusion (3.4 percent), and other sources (3.4 percent). Outflow components consisted of agricultural pumpage (91.5 percent), municipal pumpage (4.0 percent), and riparian phreatophyte evapotranspiration (4.5 percent). For the steady-state calibration, 70 percent of the simulated water levels were within 9 feet of measured water levels for 1970-81. A sensitivity analysis determined the overall stability of the model results. The model input variable that probably contributes most to the uncertainty of the results is the quantity of ground-water recharge contributed by irrigation return flow to the unconfined aquifer. A 15-percent change in the estimate of this variable causes an 11-percent change in the simulated river-seepage rate and a 6-percent change in the simulated seawater-intrusion rate. The calibrated model was used to investigate several water-resources management alternatives. Projected pumpage increase at a rate of 1 percent per year for 20 years caused declines in mean annual water levels of 10 to 20 feet in some areas and an increase in seawater intrusion from 18,900 to 23,600 acre-feet per year. Pumpage decreases in the coastal area decreased seawater intrusion more effectively than pumpage decreases farther inland. When pumpage was decreased near the coast, seawater intrusion decreased oneseventh as much. When pumpage was decreased uniformly throughout the valley, the decrease in seawater intrusion was only one-fourteenth the decrease in pumpage. Simulations indicated that replacement of ground-water pumpage with imported surface water in a 9,000-acre service area near the coast would result in a decrease in seawater intrusion equaling nearly onehalf the quantity of imported water. This further confirmed that the rate of seawater intrusion is most sensitive to pumpage near the coast.

Simulation of Groundwater and Surface-Water Resources of the Santa Rosa Plain Watershed, Sonoma County, California

U.S. Geological Survey (USGS) | April 25th, 2014

Water managers in the Santa Rosa Plain face the challenge of meeting increasing water demand with a combination of Russian River water, which has uncertainties in its fut

Water managers in the Santa Rosa Plain face the challenge of meeting increasing water demand with a combination of Russian River water, which has uncertainties in its future availability; local groundwater resources; and ongoing and expanding recycled water and water from other conservation programs. To address this challenge, the U.S. Geological Survey, in cooperation with the Sonoma County Water Agency, the cities of Cotati, Rohnert Park, Santa Rosa, and Sebastopol, the town of Windsor, the California American Water Company, and the County of Sonoma, undertook development of a fully coupled groundwater and surface-water model to better understand and to help manage the hydrologic resources in the Santa Rosa Plain watershed. The purpose of this report is to (1) describe the construction and calibration of the fully coupled groundwater and surface-water flow model for the Santa Rosa Plain watershed, referred to as the Santa Rosa Plain hydrologic model; (2) present results from simulation of the Santa Rosa Plain hydrologic model, including water budgets, recharge distributions, streamflow, and the effect of pumping on water-budget components; and (3) present the results from using the model to evaluate the potential hydrologic effects of climate change and variability without pumpage for water years 2011–99 and with projected pumpage for water years 2011–40.

Simulation of Water-Management Alternatives in the Mojave River Ground-Water Basin, California

U.S. Geological Survey (USGS) | July 1st, 2002