Shop – California Water Library

Page

Showing
571-581 of 1304

Per Page

Sort By

Hydrogeology and Water Supply of Salinas Valley

Monterey County Water Resources Agency (MCWRA) | June 15th, 1995

Summary

The Monterey County Water Resources Agency (MCWRA) convened a panel of 10 geologists, hydrogeologists, and engineers familiar with Salinas Valley ground water basin to at

The Monterey County Water Resources Agency (MCWRA) convened a panel of 10 geologists, hydrogeologists, and engineers familiar with Salinas Valley ground water basin to attempt to reach agreement on the basic physical characteristics of the basin, and the surface and ground water flow within the basin. Agreement on the completeness and accuracy of existing data and previous hydrogeological studies was seen as an important first step in identifying and implementing a technically sound solution acceptable to the public that would stop seawater intrusion that began some 60 years ago. Mike Armstrong, General Manager of MCWRA, instructed the panel to review and, if possible, reach consensus on the hydrogeological characteristics of the basin, define clearly the water resources problems in the basin, and determine surface water and ground water flow within the basin. We were not requested to discuss specific local projects or political and institutional aspects of the problems. The panel met in a closed-door session in Monterey on May 24 and 25, 1995. The session was closed to the public and the press to enable the panelists to discuss and explore ideas and opinions freely without worrying about statements, questions, and hypotheses being repeated out of context. Members of the panel believe the process worked very well. This report presents our findings, conclusions, and recommendations. We were able to achieve more than our original scope of work. There was remarkable unanimity of opinion on our understanding of the physical characteristics of the basin, the hydrologic system, the interaction between surface water and ground water, and definition of the specific ground water problems in the basin. In summary, the facts we agreed upon point so compellingly toward an already identified regional solution to the Valley's ground water resources problems that the panel has included a potential solution. We have included a strong recommendation in this White Paper for implementing that regional solution.

View Document Download Now Email

Hydrogeology of Lower Amargosa Valley and Groundwater Discharge to the Amargosa Wild and Scenic River, Inyo and San Bernardino Counties, California, and Adjacent Areas in Nye and Clark Counties, Nevada

U.S. Geological Survey (USGS) | February 7th, 2019

Summary

In 2009, Congress designated certain reaches of the Amargosa River in Inyo County, California between the town of Shoshone and Dumont Dunes as a Wild and Scenic River. As

In 2009, Congress designated certain reaches of the Amargosa River in Inyo County, California between the town of Shoshone and Dumont Dunes as a Wild and Scenic River. As part of the management of the Amargosa Wild and Scenic River, the Bureau of Land Management cooperated with the U.S. Geological Survey to assess the surface and groundwater resources of the Tecopa basin. Groundwater is the primary source of water to the perennial reaches of the Amargosa River. The U.S. Geological Survey studied the surface and groundwater systems in the basin, and assessed the sources and volume of groundwater discharging into the perennial reaches of the Amargosa Wild and Scenic River. The springs within the Tecopa basin (and the greater Lower Amargosa Valley Hydrographic Area) can be generally grouped by spring type and geographic location. There are four types of groundwater discharge points in the Tecopa basin—regional carbonate-rock springs and seeps, Tecopa Hills springs and seeps, thermal springs and seeps, and Amargosa Canyon hillslope springs and seeps. Results of chemical analysis indicate that water from all of these springs in the Lower Amargosa Valley and particularly in the Tecopa basin, is sourced in the carbonate-rock aquifer, with a local component of recharge. Groundwater is recharged in the Spring Mountains and moves through and around the Nopah and Resting Spring Ranges and into the Tecopa basin. A small (less than 1 cubic foot per second [ft3/s] or 500 acre‑feet per year) component of flow from the Amargosa Desert moves through the river channel alluvium and basin fill from the north. The location and type of spring appear to be controlled by the geology and geologic structure of the Lower Amargosa Valley. The regional springs (such as Shoshone and Borax Springs) and associated seeps tend to occur along the west side of the basin whereas other carbonate-rock aquifer springs discharge from adjacent mountain ranges, such as the Resting Spring Range, and as a result of low-permeability barriers, such as the Tecopa Hills. The thermal springs and seeps discharge from an area near the town of Tecopa, California. The Amargosa Canyon hillslope springs and seeps discharge directly into the river. Salt-crusted soils adjacent to the river indicate additional areas of diffuse discharge where groundwater is being evaporated. Perennial flow in the main channel of the Amargosa River appears to originate in an area of thermal springs near Tecopa. Persistent groundwater-fed pools begin to appear along the river channel just to the south of the Tecopa Hills. Flow between these pools is evident, but difficult to measure. During the synoptic seepage measurement survey in February 2014, flow in the Amargosa River at the Tecopa streamgage (U.S. Geological Survey site 10251300, Amargosa River at Tecopa, California) was approximately 1 ft3/s. Just to the south of the Tecopa streamgage, a line of cooler water springs (the Amargosa Canyon hillslope springs) emerges east of the river channel and continues for approximately 1 mile along the Amargosa Canyon wall. At the end of the spring reach, the flow in the river increased to just over 4 ft3/s. Flow then decreased to approximately 3 ft3/s at the confluence of Willow Creek, approximately 3.5 miles downstream. Downstream from the confluence of Willow Creek, the river consistently loses water and was dry just north of Dumont Dunes during the February 2014 synoptic seepage measurement survey.

View Document Download Now Email

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

Summary

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

View Document Download Now Email

Hydrologic and Geochemical Characterization of the Santa Rosa Plain Watershed, Sonoma County, California

U.S. Geological Survey (USGS) | July 9th, 2013

Summary

The Santa Rosa Plain is home to approximately half of the population of Sonoma County, California, and faces growth in population and demand for water. Water managers are

View Document Download Now Email

Hydrologic framework of the Santa Clara Valley, California

Geological Society of America (GSA) | June 1st, 2015

Summary

The hydrologic framework of the Santa Clara Valley in northern California was redefined on the basis of new data and a new hydrologic model. The regional groundwater flow

The hydrologic framework of the Santa Clara Valley in northern California was redefined on the basis of new data and a new hydrologic model. The regional groundwater flow systems can be subdivided into upper-aquifer and lower-aquifer systems that form a convergent flow system within a basin bounded by mountains and hills on three sides and discharge to pumping wells and the southern San Francisco Bay. Faults also control the flow of groundwater within the Santa Clara Valley and subdivide the aquifer system into three subregions. After decades of development and groundwater depletion that resulted in substantial land subsidence, Santa Clara Valley Water District (SCVWD) and the local water purveyors have refilled the basin through conservation and importation of water for direct use and artificial recharge. The natural flow system has been altered by extensive development with flow paths toward major well fields. Climate has not only affected the cycles of sedimentation during the glacial periods over the past million years, but interannual to interdecadal climate cycles also have affected the supply and demand components of the natural and anthropogenic inflows and outflows of water in the valley. Streamflow has been affected by development of the aquifer system and regulated flow from reservoirs, as well as conjunctive use of groundwater and surface water. Interaquifer flow through water- supply wells screened across multiple aquifers is an important component to the flow of groundwater and recapture of artificial recharge in the Santa Clara Valley. Wellbore flow and depth-dependent chemical and isotopic data indicate that flow into wells from multiple aquifers, as well as capture of artificial recharge by pumping of water- supply wells, predominantly is occurring in the upper 500 ft (152 m) of the aquifer system. Artificial recharge represents about one-half of the inflow of water into the valley for the period 1970–1999. Most subsidence is occurring below 250 ft (76 m), and most pumpage occurs within the upper-aquifer system between 300 and 650 ft (between 91 and 198 m) below land surface. Overall, the natural quality of most groundwater in the Santa Clara Valley is good. Isotopic data indicate that artificial recharge is occurring throughout the shallower parts of the upper-aquifer system and that recent recharge (less than 50 yr old) occurs throughout most of the basin in the upper-aquifer system, but many of the wells in the center of the basin with deeper well screens do not contain tritium and recent recharge. Age dates indicate that the groundwater in the upper-aquifer system generally is less than 2000 yr old, and groundwater in the lower-aquifer system generally ranges from 16,700 to 39,900 yr old. Depth-dependent sampling indicates that wellbores are the main path for vertical flow between aquifer layers. Isotopic data indicate as much as 60% of water pumped from production wells originated as artificial recharge. Shallow aquifers not only contain more recent recharge but may be more susceptible to anthropogenic and natural contamination, as evidenced by trace occurrences of iron, nitrate, and volatile organic compounds (VOCs) in selected water-supply wells. Water-resource management issues are centered on sustaining a reliable and good-quality source of water to the residents and industries of the valley. While the basin has been refilled, increased demand owing to growth and droughts could result in renewed storage depletion and the related potential adverse effects of land subsidence and seawater intrusion. The new hydrologic model demonstrates the importance of the aquifer layering, faults, and stream channels in relation to groundwater flow and infiltration of recharge. This model provides a means to analyze water resource issues because it separates the supply and demand components of the inflows and outflows.

View Document Download Now Email

Hydrologic Modeling Goals and Objectives for Yolo County

Water Resources Association of Yolo County, California Department of Water Resources (DWR) | May 16th, 2002

Summary

The Water Resources Association of Yolo County (WRA) has entered into a Memorandum of Understanding (MOU) with the California Department of Water Resources (DWR) to coo

View Document Download Now Email

Hydrologic Modeling of the Santa Clara River Watershed with the U.S. EPA Hydrologic Simulation Program - FORTRAN (HSPF)

Ventura County Watershed Protection District | January 24th, 2009

Summary

The purpose of the Santa Clara River (SCR) Watershed Feasibility Study as described in the PMP (October, 2003) is to determine the impact of the upstream urbanization, s

The purpose of the Santa Clara River (SCR) Watershed Feasibility Study as described in the PMP (October, 2003) is to determine the impact of the upstream urbanization, specifically in Los Angeles County, to the present natural state of the river in Ventura County and communities adjacent to the River that expect to develop close to the river banks. It is the goal of the watershed study to develop the necessary baseline data and analytical tools. In order to evaluate these impacts the feasibility study will include: • A comprehensive update of hydrologic, hydraulic, and sediment (yield and transport) models for a range of flow rates for existing conditions and future conditions within the Santa Clara River. The hydrologic model provides the flow data needed as input to the hydraulic and sediment transport models. • The hydrologic model will also be used to evaluate baseline and changes to water quality and pollutant loadings as a result of development or any proposed regional solutions to flooding or water quality problems. • Generate computer models that can simulate the impacts of land use changes under existing, natural and future conditions, and provide data to forecast the resulting changes to streamflow in the Santa Clara River. • Existing conditions include recently installed flood control and water supply/storage facilities. For future conditions, the modeling will include proposed land use changes, any additional flood control or sediment control facilities, and the effects of changes in sediment flow to the downstream areas as a result of proposed alternatives to mitigate flooding or water quality problems. The Natural Condition will be modeled by assuming the watershed has not been developed or subjected to extensive ranching or agricultural activities (pre-European). This document is the Final Report for the watershed hydrology model of the Santa Clara River Watershed using the U.S. EPA Hydrologic Simulation Program FORTRAN (HSPF). This effort was funded directly and wholly by contract with the Ventura County Watershed Protection District (VCWPD). This report identifies and describes the watershed characteristics and types of data required/available for the model, the segmentation of the watershed for modeling purposes, model calibration and validation efforts, and the results for the Baseline and Natural Conditions Scenario model runs. This effort has been designed to produce a comprehensive watershed model that meets the needs of the hydrologic model component of the SCR Watershed Feasibility Study as described above. This model was designed to: a. Represent hydrologic conditions throughout the SCR watershed for a wide range of flow conditions continuously for both high flows, low flows and individual storm events b. Provide continuous flow boundary conditions for the hydraulic and sediment transport models, at the appropriate spatial scales and boundary locations identified by the Feasibility Study participants c. Provide a modeling framework for subsequent sediment yield and water quality modeling requirements of the Feasibility Study d. Include a long-term database of 40 or more years of model input (e.g. precipitation, evaporation, diversions, POTWs) to allow long-term model simulations needed to develop the required flood (and low flow) frequency information at selected points throughout the SCR Watershed e. Provide long-term model simulations for both Baseline (current) and Natural Condition alternatives as a basis for assessing and comparing with planned Future Condition alternatives.

View Document Download Now Email

Hydrologic Models and Analysis of Water Availability in Cuyama Valley, California

U.S. Geological Survey (USGS) | May 14th, 2015

Summary

Changes in population, agricultural development practices (including shifts to more water-intensive crops), and climate variability are placing increasingly larger demand

View Document Download Now Email

Hydrological Intensification Will Increase the Complexity of Water Resource Management

American Geophysical Union (AGU) | March 9th, 2022

Summary

Climate change is intensifying the hydrologic cycle, resulting in an increase in floods and droughts. These changes increase the complexity of water resource management t

View Document Download Now Email

Hydrology of the Yucaipa Groundwater Subbasin: Characterization and Integrated Numerical Model, San Bernardino and Riverside Counties, California

U.S. Geological Survey (USGS) | January 26th, 2022

Summary

Water management in the Santa Ana River watershed in San Bernardino and Riverside Counties in southern California is a complex task with various water purveyors navigatin

Water management in the Santa Ana River watershed in San Bernardino and Riverside Counties in southern California is a complex task with various water purveyors navigating geographic, geologic, hydrologic, and political challenges to provide a reliable water supply to stakeholders. As the population has increased throughout southern California, so has the demand for water. The Yucaipa groundwater subbasin (hereafter referred to as “Yucaipa subbasin”), one of nine groundwater subbasins in what the California Department of Water Resources (DWR) refers to as the Upper Santa Ana Valley groundwater basin (California Department of Water Resources, 2016; the DWR naming convention is used within this report), is no exception; steady population growth since the 1940s and changes in water use has forced local water purveyors to regularly adapt their water infrastructure to meet demand. Groundwater has historically been the dominant source of water in the Yucaipa subbasin although recently, imported water via the California State Water Project has augmented the total water supply. Despite the influx of imported water, overall demand for groundwater continues to rise, and there is concern by local water managers that groundwater levels may adversely impact water supply and (or) decline to a point where it will be uneconomical to produce water, severely limiting the ability of local agencies to meet water-supply demand. To better understand the hydrogeology and water resources in the Yucaipa subbasin, the U.S. Geological Survey (USGS) and the San Bernardino Valley Municipal Water District initiated a cooperative study to understand the hydrogeologic system of the Yucaipa subbasin and in the encompassing Yucaipa Valley watershed (YVW). A three-dimensional hydrogeologic framework model was constructed to quantify the structure and extent of hydrogeologic units. Historical and present-day groundwater conditions were characterized to evaluate the groundwater-flow system. Lastly, the Yucaipa Integrated Hydrological Model (YIHM) was developed to simulate the integrated surface-water and groundwater systems, including natural and anthropogenic (that is, human influenced) recharge and discharge throughout the study area from 1947 to 2014. The Yucaipa subbasin is an inland groundwater basin located about 12 miles (mi) southeast of the City of San Bernardino and about 75 mi east of Los Angeles, California. The subbasin encompasses about 39 square miles (mi2), including the City of Yucaipa. The geographic extent of the Yucaipa subbasin was established by the California Department of Water Resources, who defined the boundaries of the subbasin based on hydrogeologic transitions between crystalline rock and basin-fill sediments, active fault strands, surface-water drainage divides, and a portion of an adjudicated groundwater management boundary. Two groundwater subbasins of the Upper Santa Ana Valley groundwater basin are adjacent to the Yucaipa subbasin, the San Bernardino groundwater subbasin to the west and the San Timoteo groundwater subbasin to the south. The Yucaipa subbasin is encompassed by the YVW, which is in turn comprised of three sub-watersheds that represent surface-water flow across and within the Yucaipa subbasin. Although the Yucaipa subbasin is the specific area of interest for this study, the entire YVW was considered for the purposes of characterizing the hydrogeology of the Yucaipa subbasin and for development of the YIHM. The purposes of this report are to (1) describe the hydrologic and hydrogeologic settings of the Yucaipa subbasin and aquifer system, (2) describe the construction and calibration of the fully coupled groundwater and surface-water flow model for the Yucaipa subbasin and the encompassing YVW, referred to as the YIHM, and (3) present numerical results, including water budgets and hydraulic heads, and the effect of pumping and climate stresses (precipitation and temperature) on water-budget components. This document is an executive summary. Click here for an index and links to the full report and model.

View Document Download Now Email

← Prev

Page : 58

Hydrogeology and Water Supply of Salinas Valley

Hydrogeology of Lower Amargosa Valley and Groundwater Discharge to the Amargosa Wild and Scenic River, Inyo and San Bernardino Counties, California, and Adjacent Areas in Nye and Clark Counties, Nevada

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

Hydrologic and Geochemical Characterization of the Santa Rosa Plain Watershed, Sonoma County, California

Hydrologic framework of the Santa Clara Valley, California

Hydrologic Modeling Goals and Objectives for Yolo County

Hydrologic Modeling of the Santa Clara River Watershed with the U.S. EPA Hydrologic Simulation Program - FORTRAN (HSPF)

Hydrologic Models and Analysis of Water Availability in Cuyama Valley, California

Hydrological Intensification Will Increase the Complexity of Water Resource Management

Hydrology of the Yucaipa Groundwater Subbasin: Characterization and Integrated Numerical Model, San Bernardino and Riverside Counties, California

Filter Results

Type

Topic

Keywords

Publisher

Basin

Hydrological Region

Search for:

Search the California Water Library

Type

Topic

Keywords

Hydrological Region

Basin