Sacramento River Temperature Task Group Annual Report of Activities October 1, 2013 through September 30, 2014

Delta Stewardship Council (Delta Council) | October 6th, 2014

Sacramento River Temperature Task Group Annual Report of Activities October 1, 2017 through September 30, 2018

Delta Stewardship Council (Delta Council) | November 21st, 2018

Sacramento River Temperature Task Group Annual Report of Activities, October 1, 2015 through September 30, 2016

Delta Stewardship Council (Delta Council) | October 31st, 2016

Safe Clean Water Water for Los Angeles County Residents

Los Angeles County Department of Public Works (LACDPW) | November 7th, 2017

We live in a water-scarce area, and forces outside of our control can threaten our local water resources, including lakes, rivers and beaches. LA Count

We live in a water-scarce area, and forces outside of our control can threaten our local water resources, including lakes, rivers and beaches. LA County residents rely heavily on imported water from the Sierra Mountains, the Central Valley and even from states as far away as Colorado. Climate change is causing more and more extreme weather conditions, making these remote sources more unreliable . The impacts of the recent five-year drought were widely felt here. Rainfall is an essential, local source of LA’s water . Rain runs through local rivers, creeks and streams and can be absorbed underground, replenishing groundwater, which is a local source of drinking water. However, because so much of our region is paved over, when we do experience heavy rain, too much of that precious water is lost to the ocean before we can capture it for use. Our local water resources are also threatened by toxins and pollution as stormwater runs through streets and over-paved areas into our rivers, creeks and streams. Pollution flows onto our beaches and into the ocean, posing a public health risk and harming marine life.

Sailing the Salt Line

Bay Nature | July 2nd, 2024

A strait is a place of motion. Change is a constant in our universe, a fact we humans often struggle with, but certain places are especially good at reminding us of it. T

A strait is a place of motion. Change is a constant in our universe, a fact we humans often struggle with, but certain places are especially good at reminding us of it. The Carquinez Strait itself was only just born, some 560,000 years ago—explosively, according to one theory—when a giant inland lake forced a path to the ocean. This created the unusual inverted river delta (with the fan pointing inland, instead of spreading out onto the coast) that is the San Francisco Bay.

Salinas River Watershed Area Salt Modeling

California Central Coast Regional Water Quality Control Board (CCRWQCB) | November 13th, 2015

Tetra Tech supported EPA Region 9 and the Central Coast Regional Water Quality Control Board (CCRWQCB) for an assessment of salt impairments and development of a

Tetra Tech supported EPA Region 9 and the Central Coast Regional Water Quality Control Board (CCRWQCB) for an assessment of salt impairments and development of a salt mass balance in the Lower Salinas River and Reclamation Canal watersheds. This effort can inform development of salt-related TMDLs by the CCRWQCB and a salt and nutrient management plan for the Salinas Valley aquifers. Three reaches have reported 2010 303(d) listings for salt-related impairments in these watersheds including impairments due to chloride, sodium, electrical conductivity, and total dissolved solids – Lower Salinas River, Santa Rita Creek, and Alisal Creek. This report provides data analysis and a literature review (Sections 1 through 5), development of a water and salt mass balance tool (Sections 6 through 8), and salt source assessment (Section 9). The results of the analysis provide a strong foundation for assessing salt sources and understanding salt mass balance in the study area, but can be improved with refined representation of cropland locations, rotations, and irrigation practices.

Salinity Changes the Dynamics of Pyrethroid Toxicity in Terms of Behavioral Effects on Newly Hatched Delta Smelt Larvae

Toxics (MDPI) | February 20th, 2021

Salinity can interact with organic compounds and modulate their toxicity. Studies have shown that the fraction of pyrethroid insecticides in the aqueous phase increases w

Salinity can interact with organic compounds and modulate their toxicity. Studies have shown that the fraction of pyrethroid insecticides in the aqueous phase increases with increasing salinity, potentially increasing the risk of exposure for aquatic organisms at higher salinities. In the San Francisco Bay Delta (SFBD) estuary, pyrethroid concentrations increase during the rainy season, coinciding with the spawning season of Delta Smelt (Hypomesus transpacificus), an endangered, endemic fish. Furthermore, salinity intrusion in the SFBD is exacerbated by global climate change, which may change the dynamics of pyrethroid toxicity on aquatic animals. Therefore, examining the effect of salinity on the sublethal toxicity of pyrethroids is essential for risk assessments, especially during the early life stages of estuarine fishes. To address this, we investigated behavioral effects of permethrin and bifenthrin at three environmentally relevant concentrations across a salinity gradient (0.5, 2 and 6 PSU) on Delta Smelt yolk-sac larvae. Our results suggest that environmentally relevant concentrations of pyrethroids can perturb Delta Smelt larvae behavior even at the lowest concentrations (<1 ng/L) and that salinity can change the dynamic of pyrethroid toxicity in terms of behavioral effects, especially for bifenthrin, where salinity was positively correlated with anti-thigmotaxis at each concentration.

Salinity distribution in heterogeneous coastal aquifers mapped by airborne electromagnetics

Soil Science Society of America (SSSA) | February 8th, 2011

Understanding the hydrologic setting of any given area is a challenging task, especially considering that the amount of available informaon is ofen very sparse re

Understanding the hydrologic setting of any given area is a challenging task, especially considering that the amount of available informaon is ofen very sparse relative to the size of the area and the complexity of the problem. We used geophysical transient electromagnetic (TEM) data from an airborne SkyTEM instrument to investigate discharge of freshwater from a river catchment into a coastal lagoon area, in support of large-scale hydrologic mapping of the HOBE hydrology research center. Existing hydrologic data indicate possible outflow from the catchment underneath the survey area, a hypothesis that was indeed backed up by our geophysical results. The results revealed a stratified geologic setting frequently incised by buried valleys beneath the lagoon. They also showed that the valleys are saturated with sea water, unlike the layers at the same depth that are probably saturated with brackish water. The salinity decreases with depth in large parts of the lagoon. The salinity distribution in the setting indicates the presence of intricate flow systems beneath the coastal area and the lagoon, and we propose that it is governed by the heterogeneity in the geologic setting. We also demonstrated how water depth as well as salinity can be accurately mapped using SkyTEM in combination with a robust and flexible inversion scheme.

Salinity Effects on MUN‐Related Uses of Water

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | December 1st, 2016

Purpose: Summarize current state of knowledge regarding the effects of elevated conductivity, salinity or TDS and hardness on drinking water supply

Purpose: Summarize current state of knowledge regarding the effects of elevated conductivity, salinity or TDS and hardness on drinking water supply and other domestic purposes for water use. Identify/summarize unique concerns related to specific ions (e.g. sodium, chloride, boron, etc.).

Salinity in the Central Valley: An Overview

California State Water Resources Control Board (SWRCB) | May 3rd, 2006

The Central Valley is one of the most rapidly growing areas in the nation. Population in the Valley is anticipated to increase 39% by the year 2020. Industry and urbaniza

The Central Valley is one of the most rapidly growing areas in the nation. Population in the Valley is anticipated to increase 39% by the year 2020. Industry and urbanization are taking place at an increasing pace, although agriculture is still a dominant economic force here, accounting for 57% of the $6.5 billion in sales of all agricultural products in California in 2002. The Central Valley is also home to wildlife and includes the largest contiguous wetlands area remaining in California. The warm, dry, Mediterranean climate and fertile soils have drawn agricultural users for over a century. The presence of transportation corridors and ready access to workers has enticed industry to move in, and the relatively cheap price of land has encouraged urban development. The open areas and wetlands provide vital habitat for many species, particularly migratory birds along the Pacific Flyway. But the very features that make the Central Valley desirable for wildlife, farmers, developers, industry and the general population also contribute to salinity problems. When water is used, salts are left behind. Every time a farmer irrigates a field, every time a managed wetland is flooded, every time an industrial facility conducts some water-requiring process, and every time you or I take a shower, we contribute to the salinity problem because the water we use and release has a higher salinity concentration than what we started with. Sometimes this is because we add salt intentionally (home water softeners, plant fertilizers), but even when no salts are added to the system, evaporation and consumptive use act to concentrate unused salts. Additionally, salts move with water so salts originating in one basin will turn up in another. This is a significant problem when the receiving basin has no reliable way of disposing salt, as is the case in the Tulare Lake Basin; or has only limited capacity to discharge salt, which is the case in the San Joaquin River Basin. We know today that salinity impacts are being felt in the Central Valley and that these impacts are increasing. A very preliminary analysis of salt flux in the Delta, estimated that 700 thousand tons of salt flow into the Delta from the Bay annually and are imported into the State, federal, and other water supply projects. The Tulare Lake and San Joaquin River Basins collectively receive over two million tons of salt annually through water taken in and distributed by state and federal water projects. Because the Tulare Lake Basin is a closed basin with no reliable outlet for the discharge of salts, and there is no other viable option at this time, the majority of the salt imported into the basin from the state and federal water projects (over one million tons per year) is collecting in the basin and is migrating to the basin’s groundwater. For this reason, the Central Valley Regional Water Quality Control Board’s Tulare Lake Basin Plan assumes degradation by salt is occurring in the basin and contains a controlled degradation policy for groundwater. A preliminary evaluation of salt migration to groundwater in the San Joaquin Valley estimated that over 400 thousand tons of salt per year were being added to the confined aquifer in the San Joaquin Basin. In a current study, preliminary findings of a USGS investigation have shown chloride levels in the semi-confined aquifer near Stockton are increasing and have been found to be as high as 2,200 mg/l and EC as high as 5,930 ?S/cm A simple analysis of groundwater data from 14 drinking water wells on the south side of Fresno has shown an average increase of 30 ?S/cm in the past 15 years. Although this is not a radical increase, it does indicate that salt imported into the area may be impacting the drinking water aquifer. The mean annual EC levels in the San Joaquin River near Vernalis have nearly doubled since the mid-1940s. Because the San Joaquin River is limited in its capacity to assimilate salts safely, a Total Maximum Daily Load (TMDL) has been adopted for salt and boron. The Basin Plan for the San Joaquin and Sacramento Basins has been amended to include the TMDL. The recently completed Draft Soil Survey of Fresno County, California, Western Part states that approximately 400 thousand acres of saline-sodic soils currently exist in the survey area. This acreage constitutes approximately 48 percent of the irrigated land within the boundaries of the survey area, up from approximately 33 percent of the irrigated saline-sodic land identified in 1985, an increase of approximately 120 thousand acres in 18 years. There are currently 4470 acres of active evaporation basins in the Tulare Lake Basin, and this number may be increasing due to recent legislation allowing Integrated Farm Drainage Management Systems for individual farms in salt impaired areas. The Board has stated that evaporation basins are, at best, interim salt management tools, not a final disposal option. Approximately 113 thousand acres on the west side of the San Joaquin Valley have been retired (permanently removed from irrigation) due to regional drainage problems (high salinity, shallow groundwater). More land retirement is anticipated. Salinity problems are often complicated by the presence of other materials. Soils on the west side of the San Joaquin Valley are high in selenium, so any salt management program in the area must also address selenium management. Approximately $40 million in both public and private funds has been spent (as of 2005) to manage salt and selenium problems in the Grassland Drainage Area alone. Water providers are experiencing salinity impacts and costs are being incurred and are being passed on to customers to protect their systems from corrosion and provide the quality of water needed by their customers. Agricultural, industrial, and municipal dischargers in the Region are spending increasingly greater resources on monitoring for, treating, controlling, and managing salt. Over the years, the Central Valley Regional Water Quality Control Board has been aware of the growing problem of increasing salinity in the Central Valley, but many of the key decisions that must be made in order to control Valley salinity are outside of this Board’s jurisdiction. This report is a first step in opening a dialogue between the stakeholders and decision makers that will need to be involved in a comprehensive, sustainable, salinity management program for the Central Valley and for the State of California.