Sacramento River

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.

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 Effects on Agricultural Irrigation‐related Uses

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

Purpose: Summarize current state of knowledge regarding the effects of elevated EC (TDS) concentrations on crop yields with specific attention to seasonal tolerance

Purpose: Summarize current state of knowledge regarding the effects of elevated EC (TDS) concentrations on crop yields with specific attention to seasonal tolerances. Additional information provided regarding federal, state, international regulations and guidelines and effects of elevated EC on turfgrass, landscape plants and wetland plants.

Salinity Incursion and Water Resources, Appendix to Bulletin No. 76, Delta Water Facilities

California Department of Water Resources (DWR) | April 16th, 1962

Data and analyses contained in this appendix were utilized to determine the present and future quantity and quality of water supplies within the Delta and to determine

Data and analyses contained in this appendix were utilized to determine the present and future quantity and quality of water supplies within the Delta and to determine the conditions under which the State Water Facilities must operate within the Delta with the various facilities proposed in Bulletin No. 76 constructed therein. In general, the conditions imposed result from conservative assumptions of available water supply and Delta channel hydraulics.

Salinity Management Strategy Report

Central Valley Regional Water Quality Control Board (CVRWQCB) | July 29th, 2008

The mission of the Central Valley Salinity Policy Group is to work closely, in a collaborative manner to create a comprehensive Central Valley Salinity Management Plan. T

The mission of the Central Valley Salinity Policy Group is to work closely, in a collaborative manner to create a comprehensive Central Valley Salinity Management Plan. This mission is presented at all meetings and forms the basis for the efforts of the group. This report and its plans and strategies are intended to further the initial efforts of the group in fulfilling its mission. The purpose of this report is to document the strategies discussed and proposed to provide an overall roadmap developing efforts that lead to solving salinity issues in the Central Valley Region. While these efforts are just beginning and will take a long time to come to fruition many of them need to be started now to be successful. The document collects materials and information prepared with the committees and group participants as they worked during most of 2007 and early 2008. The report attempts to capture this progress and provide summary information that would be useful to current and future participants, the Regional Board and Salinity Policy Group members. Within this document no specific regulatory or policy decisions related to salinity have been made by the Salinity Policy Group or Waterboards. Changes to the outline of this document were made to include efforts that were undertaken to assist the groups in planning and working on issues important to the group over the contract term. Additionally, some technical information and integration of existing technical studies is omitted from this report as several of these studies are ongoing and will not be completed in time to report their findings in this report.

Salinity of deep groundwater in California: Water quantity, quality, and protection

National Academy of Sciences (NAS) | July 12th, 2016

Deep groundwater aquifers are poorly characterized but could yield important sources of water in California and elsewhere. Deep aquifers have been developed for oil and g

Deep groundwater aquifers are poorly characterized but could yield important sources of water in California and elsewhere. Deep aquifers have been developed for oil and gas extraction, and this activity has created both valuable data and risks to groundwater quality. Assessing groundwater quantity and quality requires baseline data and a monitoring framework for evaluating impacts. We analyze 938 chemical, geological, and depth data points from 360 oil/gas fields across eight counties in California and depth data from 34,392 oil and gas wells. By expanding previous groundwater volume estimates from depths of 305 m to 3,000 m in California’s Central Valley, an important agricultural region with growing groundwater demands, fresh [<3,000 ppm total dissolved solids (TDS)] groundwater volume is almost tripled to 2,700 km3, most of it found shallower than 1,000 m. The 3,000-m depth zone also provides 3,900 km3 of fresh and saline water, not previously estimated, that can be categorized as underground sources of drinking water (USDWs; <10,000 ppm TDS). Up to 19% and 35% of oil/gas activities have occurred directly in freshwater zones and USDWs, respectively, in the eight counties. Deeper activities, such as wastewater injection, may also pose a potential threat to groundwater, especially USDWs. Our findings indicate that California’s Central Valley alone has close to three times the volume of fresh groundwater and four times the volume of USDWs than previous estimates suggest. Therefore, efforts to monitor and protect deeper, saline groundwater resources are needed in California and beyond.

Salt Water Problem: San Francisco Bay and Delta of Sacramento and San Joaquin Rivers

Association of Industrial Water Users of Contra Costa and Solano Counties | April 12th, 1928

PENETRATION OF SALT WATER IN UPPER BAY AND LOWER RIVER REGiON Under natural conditions, Carquinez Straits marked, approximately, the boundary between salt and fresh

PENETRATION OF SALT WATER IN UPPER BAY AND LOWER RIVER REGiON Under natural conditions, Carquinez Straits marked, approximately, the boundary between salt and fresh water in the upper San Francisco Bay and delta region of the two tributary rivers-the Sacramento and San Joaquin. Ordinarily salt water was present below the straits and fresh water was present above. Native vegetation in the tide marshes was predominantly of salt water types around San Pablo Bay and of fresh water types around Suisun Bay. In tidal waters, into which run fresh water streams of variable flow, there is an ebb and flow of salt water and the zone of mixing will move up and down stream as the fresh water flow increases and decreases. For short intervals in late summer of years of minimum flow, salt water penetrated the lower river and delta region, and in wet seasons the upper bay was fresh, part of the time, to the Golden Gate. This variation in quality of water was not, however, of sufficient duration to affect the characteristic vegetation growth of the regions on each side of the straits, nor to change the designation of Suisun Bay as ordinarily a fresh water body and San Francisco Bay as salt water. The works of man have changed conditions in many ways. The most important changes have been brought about gradualJy,-so slowly as to be hardly noticeable. The dry season of 1918,-when large summer diversions for irrigation in the Sacramento Valley resulted in the sudden penetration of salt water farther upstream than ever known before, at such an early period in summer first brought the salt water problem to public notice. The slow effects of increasing diversions in previous years had escaped notice, but were brought prominently to the attention of the inhabitants of the upper bay and delta regions in this year. Since 1918, the dry years of 1920, 1924- and 1926 have more convincingly demonstrated the importance of the salt water problem. An accurate picture of natural conditions is not possible, because no records have been collected on which such a picture can be based, but very close approximations can be made. The log of the distance traveled by the water barge of the California Hawaiian Sugar Company in going upstream to obtain fresh water has been kept since 1908. These figures give the means of determining approximately the conditions during that period. In 1908 irrigation had been extensively developed in both valleys and conditions then were not natural. For an estimate of earlier conditions we must go to the stream flow records of the tributary streams before important diversions are taken out. It is the practice of the Sugar Company to send the barge upstream until water of approximately 50 to 70 parts per million chlorine is reached. The crew of the barge are equipped with apparatus by which water is analyzed until this degree of purity is reached. Since trips are made nearly every day during the summer months, the record is a very good indication of the point reached by salt water. A summary of the complete records shows the fluctuation of the line between fresh and salt water. Records of the Sugar Company arc attached. (Table 1.) The Sugar Company requires water of great purity. For irrigation, domestic or ordinary industrial uses, water of a lesser degree of purity may be used. A comparison of the point where the Sugar Company's barge is filled with the point where the remaining uses could be satisfied, indicates that from five to ten miles downstream from the place where the barge turns, water could be obtained satisfactory for domestic supply. Making an allowance of 7 1/2 miles in the average records, we find that an average flow of 5,000 second feet in both streams will maintain fresh water at Collinsville; 7,000 second feet will maintain fresh water at the San Francisco-Sacramento ferry. If we sum up the flow of the important tributaries of the Sacramento and San Joaquin rivers at the points where these streams leave the mountains and assume that this flow under natural conditions would have reached the head of the Suisun Bay we will find that at no time in the past ten years would the average monthly flow have been Jess than 5,100 second feet. It is probable, should all streams be running in a natural way, that salt water would have penetrated no farther in this extremely dry period than Antioch, and then only for a few days at a time. It is not possible to make a more detailed study of this condition without making a number of assumptions as to speed of flow from the gaging stations to the head of the bay, and there is little accurate information on which the assumptions may be made. The definite statement that salt water under natural conditions did not penetrate higher upstream than the mouth of the river, except in the driest years and then only for a few days at a time, is warranted. (See Table 2 for monthly flow of tributary streams.) At present salt water reaches Antioch every year, in two-thirds of the years running further upstream. It is to be expected that it will continue to do so in future, even in years of greatest runoff. In other words, the penetration of salt water has become a permanent phenomenon in the lower river region.

Sampling for Per- and Polyfluoroalkyl Substances (PFAS) by the Groundwater Ambient Monitoring and Assessment Priority Basin Project

Publisher not available | May 25th, 2021

San Francisco Bay California Toxics Rule Priority Pollutant Ambient Water Monitoring Report

San Francisco Estuary Institute (SFEI) | February 1st, 2017

In 2000, the USEPA published Water Quality Standards; Establishment of Numeric Objectives for Priority Toxic Pollutants for the State of California, commonly known as t

In 2000, the USEPA published Water Quality Standards; Establishment of Numeric Objectives for Priority Toxic Pollutants for the State of California, commonly known as the California Toxics Rule (CTR), which established numeric water quality standards for 126 priority pollutants. Under the Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California (also known as the State Implementation Policy, SIP) the San Francisco Bay Regional Water Quality Control Board (SFBRWQCB) is required to establish water quality-based effluent limitations in order to achieve priority pollutant standards. For the purposes of this document “water quality criteria” (WQCs) will be used to refer both to the CTR established numeric criteria for 126 priority pollutants as well as to numeric objectives for 12 of these priority pollutants and tributyltin previously established in the San Francisco Bay Water Quality Control Plan (Basin Plan) and/or the National Toxics Rule. A number of these pollutants previously were or continue to be regularly monitored as part of the Regional Monitoring Program Status and Trends (RMP S&T). The priority pollutants not routinely included in RMP S&T were previously monitored in wet and dry season ambient water sampling in 2002 and 2003. Results of that effort are detailed in a previously issued : Most of the priority pollutants were not detected in that study, or detected at concentrations below their WQC. Among the pollutants that were detected, a number of them were also found at similar concentrations in lab blanks, suggesting they might not have been present (or at least were at lower concentrations) in the ambient environment. Since over a decade had passed since that previous monitoring effort, the RMP embarked on an effort to repeat measurement of these seldom analyzed (non- S&T) contaminants, to ensure conditions have not changed appreciably to present greater risk for any of them.

San Francisco Bay: A Freshwater Starved Estuary

Bay Institute | September 1st, 2016

How Reducing Flows Harms the Ecosystems of San Francisco Bay and Coastal Waters The Bay Institute’s major new study, San Francisco Bay: The Freshwater – Starved Estu

How Reducing Flows Harms the Ecosystems of San Francisco Bay and Coastal Waters The Bay Institute’s major new study, San Francisco Bay: The Freshwater – Starved Estuary, documents how the ecological health of San Francisco Bay and the nearby ocean is at high risk because large-scale water diversion in the Bay’s watershed severely limits the amount of fresh water that reaches the Bay and alters the timing of that flow. Inflow to the Bay from its Central Valley watershed now averages less than half of what it would be without diversions; in some years just one-third of the runoff makes it to the Bay. The result is a nearly permanent drought for the Bay’s fish, wildlife, and their habitats. This radical alteration creates severe consequences for the Bay and marine ecosystems – and Bay Area residents pay the price. The study shows how unsustainable diversion of the Bay’s freshwater inflow: Dramatically cuts production of fish and shrimp that are the food source for marine mammals, like Orca Whales, and birds; Allows pollutants to accumulate to dangerous levels and encourages blooms of toxic algae; Reduces sediment supply to Bay Area wetlands and beaches; Makes it easier for undesirable non-native species to successfully invade the Bay Estuary. The San Francisco Bay Estuary is created by the mixing of fresh water from the Central Valley’s rivers with salt water from the Pacific Ocean. Dramatically reducing the inflow of fresh water generates cascading effects in the Bay’s watershed, the Bay itself, and coastal ocean waters. The report’s major findings include: On average, since 1975 more than half (53%) of runoff from the Central Valley watershed has been diverted, stored, or exported before it can reach the Bay – and in many years two-thirds or more of the Bay’s inflow is captured; As a result of intensive water diversions, the Bay experiences catastrophically dry years almost half the time (only one “supercritically dry” year occurred naturally between 1975-2014, but the Bay experienced nineteen supercritical years during that period); Numerous unrelated fish species – from sharks to salmon, from sturgeon to smelt – show strong positive correlations with Bay Inflow; many of these species are now endangered, and even commercially viable fisheries are in decline; Predators that feed on flow-dependent fish and shrimp are feeling the pinch – for example, dwindling supplies of Central Valley Chinook salmon may restrict the recovery of the local Orca whale population; Blooms of toxic “algae” (cyanobacteria) are becoming more frequent, and other pollutants are becoming more concentrated, as a result of reductions in freshwater flows from the Bay’s watershed; Bay Area beaches and tidal wetlands are deprived of sediment that was once transported by high river flows. The study reports that local businesses are likely to suffer from the Bay’s continued decline, including those related to commercial fishing and tourism. As our Bay, beaches, wetlands, and fish and wildlife populations deteriorate, the quality of life for many Bay Area residents will also be severely – and perhaps permanently – damaged. The study identifies four important approaches to improving Bay inflows: Update the State’s 21 year old water quality standards for the Bay Estuary to ensure adequate inflow Require all those who divert water destined for the Bay, not just a subset, to contribute their fair share of fresh water to support benefits enjoyed by all Californians Invest in local water supplies around the state including conservation, and recycling, that can generate millions of acre-feet of water and reduce reliance on water diverted from the Estuary and its watershed Coordinate management of flows with wetland and beach restoration to more effectively protect shorelines The study was prepared for the San Francisco Estuary Partnership, a coalition of resource agencies, non-profits, citizens, and scientists working to protect, restore, and enhance water quality and fish and wildlife habitat in and around the San Francisco Bay Delta Estuary, which also provided the majority of funding for the project.