Hydroclimate Report Water Year 2016

California Department of Water Resources (DWR) | September 5th, 2017

Water year 2016 ended up being different than expected, from a climate standpoint. Water year 2015 marked the 4th year of drought in California, ending with record high t

Water year 2016 ended up being different than expected, from a climate standpoint. Water year 2015 marked the 4th year of drought in California, ending with record high temperatures, record low precipitation, and a record low snowpack. Forecasts were for a strong, wet El Nino during water year 2016, with the potential to rival large flood producing events of 1983 and 1998, higher than average sea levels, increased wave action and potential damage along the coast, warmer than average temperatures, and above-average precipitation producing storms. As a result of the cooling of the tropical Pacific sea surface temperatures, and the decay of El Nino, only some of the anticipated impacts were realized, above-average precipitation and greater than average snowpack did not come to pass. While statewide air temperatures averaged lower than the record setting 2015 water year they were still well above the long-term record, ranking water year 2016 warmest 117 of 121 since 1895. Precipitation was above normal in the Northern Sierra with the majority of precipitation falling in January and March. Precipitation in the Southern Sierra was on average with the long-term trend. Differences in Northern and Southern Sierra precipitation were due to the majority of Atmospheric River landfalls occurring in the north including the two strongest occurring in the first two weeks of March while only two Atmospheric Rivers made landfall south of Monterey Bay. Statewide snowpack was 15 percent below average and impacted the April-July snowmelt with streamflow on the Sacramento and San Joaquin Rivers by 32 percent and 22 percent below average respectively. Water year type was classified as “Below Normal” for the Sacramento River system and “Dry” for the San Joaquin. Overall, water year 2016 was an improvement to the previous four years of drought conditions with enough precipitation to offset some of the large deficits in water storage reservoirs.

Hydroclimate Report Water Year 2017

California Department of Water Resources (DWR) | August 1st, 2018

Water year (WY) 2017 began with lingering impacts from a severe and prolonged drought mitigated slightly by the previous WY. Expectations were uncertain for the W

Water year (WY) 2017 began with lingering impacts from a severe and prolonged drought mitigated slightly by the previous WY. Expectations were uncertain for the WY with the potential for a weak La Nina event taking shape in the eastern tropical Pacific. Dry weather, cold storms or warm storms are all possible in this circulation pattern. No one foresaw the epic year that was about to unfold.

Hydrogeologic evaluation and numerical simulation of the Death Valley regional ground-water flow system, Nevada and California

U.S. Geological Survey (USGS) | July 1st, 1997

Hydrogeologic Investigation Arroyo Seco Cone

Monterey County Water Resources Agency (MCWRA) | April 15th, 1994

This report presents the findings, analysis, conclusions, and recommendations developed as part of an investigation to characterize the hydrogeology of the Arroyo Seco Co

This report presents the findings, analysis, conclusions, and recommendations developed as part of an investigation to characterize the hydrogeology of the Arroyo Seco Cone area of the Salinas Valley. The purpose of this investigation is to assess the feasibility of developing a seasonal surface water spreading operation utilizing water diverted from the Arroyo Seco in order to enhance ground water recharge in the area. The goal of a project to store water in the ground for subsequent pumping and use is to increase the yield of the Salinas Basin. This investigation defines the hydrogeologic characteristics of the Arroyo Seco Cone area, characterizes the hydrology of the Arroyo Seco and the availability of divertable flows, and estimates the annual recharge that could be achieved through the development of spreading basins.

Hydrogeology and Simulation of Groundwater Flow in the Lucerne Valley Groundwater Basin, California

U.S. Geological Survey (USGS) | June 28th, 2022

The Lucerne Valley is in the southwestern part of the Mojave Desert and is about 75 miles northeast of Los Angeles, California. The Lucerne Valley groundwater basin encom

The Lucerne Valley is in the southwestern part of the Mojave Desert and is about 75 miles northeast of Los Angeles, California. The Lucerne Valley groundwater basin encompasses about 230 square miles and is separated from the Upper Mojave Valley groundwater basin by splays of the Helendale Fault. Since its settlement, groundwater has been the primary source of water for agricultural, industrial, municipal, and domestic uses. Groundwater withdrawal from pumping has exceeded the amount of water recharged to the basin, causing groundwater declines of more than 100 feet between 1917 and 2016 in the center of the basin. The continued withdrawal has resulted in an increase in pumping costs, reduced well efficiency, and land subsidence near Lucerne Lake. Although the volume of pumping has declined in recent years, there is concern that new agricultural growth and limits on imported water will continue to strain the sustainability of the groundwater system.

Hydrogeology, Hydrologic Effects of Development, and Simulation of Groundwater Flow in the Borrego Valley, San Diego County, California

U.S. Geological Survey (USGS) | November 24th, 2015

The Borrego Valley is a small valley (110 square miles) in the northeastern part of San Diego County, California. Although the valley is about 60 miles northeast of city

The Borrego Valley is a small valley (110 square miles) in the northeastern part of San Diego County, California. Although the valley is about 60 miles northeast of city of San Diego, it is separated from the Pacific Ocean coast by the mountains to the west and is mostly within the boundaries of Anza-Borrego Desert State Park. From the time the basin was first settled, groundwater has been the only source of water to the valley. Groundwater is used for agricultural, recreational, and municipal purposes. Over time, groundwater withdrawal through pumping has exceeded the amount of water that has been replenished, causing groundwater-level declines of more than 100 feet in some parts of the basin. Continued pumping has resulted in an increase in pumping lifts, reduced well efficiency, dry wells, changes in water quality, and loss of natural groundwater discharge. As a result, the U.S. Geological Survey began a cooperative study of the Borrego Valley with the Borrego Water District (BWD) in 2009. The purpose of the study was to develop a greater understanding of the hydrogeology of the Borrego Valley Groundwater Basin (BVGB) and to provide tools to help evaluate the potential hydrologic effects of future development. The objectives of the study were to (1) improve the understanding of groundwater conditions and land subsidence, (2) incorporate this improved understanding into a model that would assist in the management of the groundwater resources in the Borrego Valley, and (3) use this model to test several management scenarios. This model provides the capability for the BWD and regional stakeholders to quantify the relative benefits of various options for increasing groundwater storage. The study focuses on the period 1945–2010, with scenarios 50 years into the future.

Hydrologic Analysis of Mojave River Basin, California, Using Electric Analog Model

U.S. Geological Survey (USGS) | August 18th, 1971

Hydrologic and geochemical characterization of the Petaluma River watershed, Sonoma County, California

U.S. Geological Survey (USGS) | January 31st, 2022

Principal water agencies in the Petaluma Valley groundwater basin seek to understand the availability of groundwater to meet increasing regional water supply demand cause

Principal water agencies in the Petaluma Valley groundwater basin seek to understand the availability of groundwater to meet increasing regional water supply demand caused by increasing agricultural and urban water demands. Surface water from the Russian River is the primary water supply in the basin, but the future availability of this surface-water supply is uncertain. Groundwater is an important supplemental source of water for the City of Petaluma and the primary supply for agriculture and domestic use by rural property owners. Furthermore, supplies of recycled water are becoming more available. Water managers face the challenge of meeting increasing water demand with a combination of surface water, local groundwater resources, and use of recycled wastewater. In 2014, California adopted legislation to manage groundwater: the Sustainable Groundwater Management Act (SGMA). The SGMA requires the development and implementation of Groundwater Sustainability Plans (GSPs) in 127 medium- or high-priority groundwater basins, and the Petaluma Valley groundwater basin was designated as a high-priority basin. Sustainability is defined within the SGMA in terms of avoiding undesirable results: significant and unreasonable groundwater-level declines, reduction in groundwater storage, seawater intrusion, water-quality degradation, land subsidence, and surface-water depletion. The U.S. Geological Survey (USGS), in cooperation with the Sonoma County Water Agency (SCWA) and the City of Petaluma, characterized the hydrology of the Petaluma valley watershed (PVW) and developed an integrated hydrologic model that can be used to improve understanding and management of the groundwater system and develop a GSP. The objectives of the study are to (1) develop an updated assessment of the hydrogeology and geochemistry of the PVW and (2) develop an integrated hydrologic model for the PVW. The purpose of this report is to describe the conceptual model of the hydrologic, hydrogeologic, and water-quality characteristics of the PVW and a numerical groundwater-flow model of PVW.

Hydrology of the San Bernardino and Eastern San Gabriel Mountains, California

U.S. Geological Survey (USGS) | July 15th, 1954

Man's successful occupancy and development of the arid and semiarid parts of the earth will always be a planned and slow process. Planning is necessary be- cause the amou

Man's successful occupancy and development of the arid and semiarid parts of the earth will always be a planned and slow process. Planning is necessary be- cause the amount and distribution of the precipitation will generally not support the food crops to which he is accustomed. To provide the soil with enough mois- ture for crops, supplemental waters must be obtained from ground-water sources, distant surface streams, or from storage in mountain reservoirs. The planning, financing, and development of these supplemental sources require the united effort of many individuals, and as the population increases, water supplies that were once adequate may become insufficient. Thus, man is continually faced with the problem of obtaining enough water of high enough quality to meet his in- creasing demands. The problem requires an under- standing of the natural laws of occurrence and distribution of the water in the air, on the earth's surface, and underground. All life is dependent on these sources of water.

Identification of fresh submarine groundwater off the coast of San Diego, USA, using electromagnetic methods

Hydrogeology Journal (Springer) | March 1st, 2022

Climate change has a pronounced effect on water resources in many semiarid climates, causing populated areas such as San Diego County (USA), to become more vulnerable to

Climate change has a pronounced effect on water resources in many semiarid climates, causing populated areas such as San Diego County (USA), to become more vulnerable to water shortages in the coming decades. To prepare for decreased water supply, San Diego County is adopting policies to decrease water use and to develop additional local sources of water. One new local source of freshwater is produced by a desalination facility that purifies brackish groundwater from the coastal San Diego Formation. This formation has been studied extensively onshore, but little is known about the geology or groundwater quality offshore in the adjacent continental shelf. Because most groundwater systems are interconnected and complex, further analysis is needed to identify offshore geology, possible sequestration of freshwater in the shelf, and potential pathways for saltwater intrusion. This comprehensive understanding is important because seawater intrusion may limit use of the San Diego Formation and longevity of desalination facilities. Controlled-source electromagnetic methods are uniquely suited to detecting offshore groundwater as they are sensitive to changes in pore fluids such as the transition from fresh to brackish groundwater. This paper describes results from surface-towed electromagnetic surveys that mapped the pore-fluid salinity and possible fluid pathways in the continental shelf off the coast of San Diego. The results indicate a considerable volume of fresh-to-brackish groundwater sequestered in the shelf, both in continuous lenses and isolated pockets, that appear influenced by fault systems and shallow stratigraphy.