South Coast

Strategic Plan to Protect California Coast and Ocean 2020-2025

California Ocean Protection Council (COPC) | February 26th, 2020

Strategic stream gauging network design for sustainable water management

Nature Portfolio (Springer Nature) | June 3rd, 2024

Stream gauging stations that monitor the flow of water in rivers and streams provide critical information to water managers, but biases and gaps in gauge placement, compo

Stream gauging stations that monitor the flow of water in rivers and streams provide critical information to water managers, but biases and gaps in gauge placement, compounded by gauge deactivations, limit our ability to track river flows and address global water challenges. Here we introduce an approach for identifying gauging sites to efficiently fill gaps in monitoring coverage within river networks while also addressing water management priorities, including reservoir operations, biodiversity conservation and hydroclimatic monitoring. Applying this approach to gauges in California, United States, we found substantial gaps in the stream monitoring network. Hypothetically reconfiguring gauges to locations that maximize coverage and representation of management objectives highlights the current network’s biases. Through the strategic reactivation and placement of additional gauges, we demonstrate how stream gauging networks can be designed to support sustainable water management.

Stratigraphic controls on seawater intrusion and implications for groundwater management, Dominguez Gap area of Los Angeles, California, USA

Hydrogeology Journal (Springer) | May 30th, 2009

Groundwater pumping has led to extensive waterlevel declines and seawater intrusion in coastal Los Angeles, California (USA). A SUTRA-based solute-transport model was dev

Groundwater pumping has led to extensive waterlevel declines and seawater intrusion in coastal Los Angeles, California (USA). A SUTRA-based solute-transport model was developed to test the hydraulic implications of a sequence-stratigraphic model of the Dominguez Gap area and to assess the effects of water-management scenarios. The model is two-dimensional, vertical and follows an approximate flow line extending fromthe Pacific Ocean through the Dominguez Gap area. Results indicate that a newly identified fault system can provide a pathway for transport of seawater and that a stratigraphic boundary located between the Bent Spring and Upper Wilmington sequences may control the vertical movement of seawater. Three 50-year water-management scenarios were considered: (1) no change in water-management practices; (2) installation of a slurry wall; and (3) raising inland water levels to 7.6m above sea level. Scenario 3 was the most effective by reversing seawater intrusion. The effects of an instantaneous 1-m sealevel rise were also tested using water-management scenarios 1 and 3. Results from two 100-year simulations indicate that a 1-m sea-level rise may accelerate seawater intrusion for scenario 1; however, scenario 3 remains effective for controlling seawater intrusion.

Studies of Geology and Hydrology in the Basin and Range Province, Southwestern United States, For Isolation of High-Level Radioactive Waste Characterization of the Sonoran Region, California

U.S. Geological Survey (USGS) | July 15th, 1989

A study by the U.S. Geological Survey to evaluate potential hydrogeologic environments for isolation of high-level radioactive waste in the Basin and Range physiographic

A study by the U.S. Geological Survey to evaluate potential hydrogeologic environments for isolation of high-level radioactive waste in the Basin and Range physiographic province of the southwestern United States was begun in May 1981, with the introduction of the study to the Governors of eight Basin and Range States Arizona, California, Idaho, Nevada, New Mexico, Oregon, Texas, and Utah and to respective Indian tribes in those States. Accordingly, these States were invited to participate in the study by designating an earth scientist to serve on a Province Working Group with the U.S. Geological Survey membership of the working group is shown following the title page. State representatives have provided consultation in selecting guidelines, assembling geologic and hydrologic data, and assessing such information to identify environments that meet the guidelines for further study.

Study to Evaluate Long-Term Trends and Variations in the Average Total Dissolved Solids Concentration in Wastewater and Recycled Water

Southern California Salinity Coalition | March 30th, 2018

This report was funded by the Southern California Salinity Coalition (SCSC). SCSC and its member agencies are dedicated to managing salinity in the water supplies, waste

This report was funded by the Southern California Salinity Coalition (SCSC). SCSC and its member agencies are dedicated to managing salinity in the water supplies, wastewater, and recycled water. Member agencies include Eastern Municipal Water District (EMWD), Inland Empire Utilities Agency (IEUA), Metropolitan Water District of Southern California (MWDSC), Orange County Sanitation District (OCSD), Orange County Water District (OCWD), San Diego County Water Authority (SDCWA), Sanitation Districts of Los Angeles County (LACSD), and Santa Ana Watershed Project Authority (SAWPA). Daniel B. Stephens & Associates, Inc. (DBS&A) performed the analysis and is submitting this technical memorandum to address the research questions posed by SCSC and its member agencies. The 2011 to 2016 drought in California, in conjunction with unprecedented statewide conservation legislation, caused several member agencies to face challenges meeting regulatory water quality standards for the salinity of discharge water from wastewater treatment plants (WWTPs). In particular, total dissolved solids (TDS) concentrations have increased, while the operation of WWTPs have remained consistent with prior years. Figure ES-1 is a typical example of TDS trends for WWTPs in Southern California.

Summary and Evaluation of Southern California Coast Steelhead Distinct Population Segment 2016

National Marine Fisheries Service (NMFS) | March 27th, 2016

The Southern California Coast Steelhead Distinct Population Segment (DPS) is listed as endangered and is comprised of a suite of steelhead populations (Oncorhynchus mykis

The Southern California Coast Steelhead Distinct Population Segment (DPS) is listed as endangered and is comprised of a suite of steelhead populations (Oncorhynchus mykiss) that inhabit coastal stream networks from the Santa Maria River system south to the U.S. border with Mexico. Freshwater-resident (non-anadromous) O. mykiss, commonly known as rainbow trout, also occur in the same geographic region, frequently co-occurring in the same river systems as the anadromous form. Clemento et al. (2009) found that O. mykiss above and below impassable dams within the Southern California DPS tended to be each other’s closest relatives, suggesting that each steelhead DPS is simply the anadromous component of a corresponding Evolutionarily Significant Unit (ESU; Waples 1991) comprising both anadromous and resident O. mykiss. West Coast salmon and steelhead (Oncorhynchus spp.) stocks have declined substantially from their historic numbers and many are now listed as threatened or endangered. Multiple factors have contributed to the decline of individual populations. These include the loss of freshwater and estuarine habitat, periodic poor ocean conditions, and a variety of land-use, flood control, and water management practices which have impacted many watershed-wide processes; these include hydrologic and sedimentation processes which create and maintain essential steelhead habitats. These factors collectively led the National Marine Fisheries Service (NMFS) to list southern California steelhead (the anadromous form of O. mykiss) as endangered under the ESA in 1997 (Figure 1). Section 4(c)(2) of the ESA directs the Secretary of Commerce to review the listing classification of threatened and endangered species at least once every five years. After completing this review, the Secretary must determine if any species should be: (1) removed from the list; (2) have its status changed from threatened to endangered; or (3) have its status changed from endangered to threatened. The most recent listing determinations for salmon and steelhead occurred in 2005 and 2006. This document reflects the agency’s 5-year status review of the ESAlisted Southern California Coast Steelhead Distinct Population Segment (DPS) since the last status review in 2010 (Williams et al. 2011).

Surface Water-Groundwater Interaction Report, Ventura River Habitat Conservation Plan, Ventura River, California

County of Ventura | February 12th, 2001

ENTRIX, Inc. was contracted by the Cooperating Agencies to perform an analysis of surface water and groundwater hydrology in the Ventura River basin as part of th

ENTRIX, Inc. was contracted by the Cooperating Agencies to perform an analysis of surface water and groundwater hydrology in the Ventura River basin as part of the Habitat Conservation Plan (HCP) for the Ventura River in Ventura County, California. The Cooperating Agencies consist of the County of Ventura, the Ventura County Flood Control District (VCFCD), the City of San Buenaventura, the Casitas Municipal Water District (Casitas), the Meiners Oaks County Water District (MOCWD), the Ojai Valley Sanitary District (OVSD), the Ojai Basin Groundwater Management Agency, the Southern California Water Company (SCWC), the Ventura County Water Agency, and the City of Ojai. These agencies all operate and maintain facilities that may affect sensitive biological resources along the Ventura River. To comply with the Endangered Species Act (ESA), the agencies are developing a HCP in consultation with the National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Service (USFWS) to serve as the basis for an Incidental Take Permit. The objectives of the surface water-groundwater interaction evaluation, outlined in The Ventura River Habitat Conservation Plan Technical Approach dated March 30, 2000, are to develop an improved understanding of the hydrologic system dynamics and determine the likelihood of groundwater pumping impacts on surface flows, based on available empirical data. The scope of work involved collecting and evaluating available surface flow and groundwater data and prior analyses of the surface and groundwater system. The focus of the evaluation was on the river reaches where the Cooperating Agencies can affect flow. The availability of concurrent surface flow and groundwater data determined the study period(s) and specific reaches analyzed. The study is focused on the Upper Ventura River and San Antonio Creek basins, and a brief discussion is also included for the Ojai Valley groundwater basin. The data reviewed as part of the evaluation included seasonal changes in groundwater levels and groundwater storage, groundwater flow relationships, and estimated contributions from groundwater to surface water.

Sustainable L.A. Grand Challenge Environmental Report Card for Los Angeles County: Water 2019

University of California, Los Angeles (UCLA) | October 22nd, 2019

The Sustainable LA Grand Challenge (SLA GC) Environmental Report Card (ERC) for Los Angeles County (L.A. County) is the only comprehensive environmental report card for

The Sustainable LA Grand Challenge (SLA GC) Environmental Report Card (ERC) for Los Angeles County (L.A. County) is the only comprehensive environmental report card for a megacity in the world. This 2019 ERC on Water provides an in-depth look at the region’s efforts in moving toward a more resilient local water supply, which requires maximizing high quality local water supplies, improving water conveyance and treatment infrastructure, reducing water consumption, and implementing innovative technology and policy solutions. Twenty indicators were assessed across eight categories. Many of these indicators are new areas of assessment for the ERC and will provide a more comprehensive picture of current conditions compared to the 2015 ERC that last assessed L.A. County’s water. Grades were assigned in each category based on compliance with environmental laws or numeric standards where applicable, on our best professional judgment, and on historical improvements and context. This year’s grades range from D/ Incomplete to B+, and although there has been great progress in some areas, others still require significant improvement to raise the county’s C+ average.

Sustainable Landscapes in California: A Guidebook for Commercial and Industrial Site Managers

Pacific Institute | August 20th, 2020

Sustainable landscaping offers a solution in balance with the local climate and ecology, and actively contributes to community and watershed health by providing economic,

Sustainable landscaping offers a solution in balance with the local climate and ecology, and actively contributes to community and watershed health by providing economic, social, and environmental benefits. This guidebook provides simple steps to consider, select, and install sustainable landscaping. Aimed specifically at businesses and communities in California, the guidebook includes information on turf replacement, installation of bioswales and rain gardens, permeable pavement, green roofs, and rain tanks and cisterns. Self-assessments guide the user through the selection and installation process.

Sustainable Landscapes on Commercial and Industrial Properties in the Santa Ana River Watershed

Pacific Institute | February 14th, 2019

Pressures on water resources are intensifying due to aging infrastructure, population growth, climate change, and other factors. Marked by vast expanses of thirs

Pressures on water resources are intensifying due to aging infrastructure, population growth, climate change, and other factors. Marked by vast expanses of thirsty lawns and impermeable pavement, California’s urban and suburban communities are ill-equipped to handle these pressures. Outdoor use represents about half of all water used in urbanized areas, and even more in the hottest, driest parts of the state.1,2 Runoff from lawns carries fertilizers and pesticides into waterways. Similarly, impermeable pavement impedes groundwater recharge; contributes to higher peak flows; warms the urban environment; and carries oils, metals, and other toxins into rivers, estuaries, and the ocean. The good news is that there are more sustainable options for California communities. Replacing lawns with climate-appropriate plants that are irrigated efficiently can save water and reduce vulnerability to drought. When integrated with bioswales, rain gardens, and other green infrastructure, these projects can boost local water supplies, reduce flooding, and improve water quality. These practices can also save energy, provide habitat, sequester carbon, improve air quality, boost property values, enhance community livability, and increase resilience to climate change.