South Coast

Recommendations to the State Water Resources Control Board Pursuant to California Water Code Section 10609

California Department of Water Resources (DWR) | September 29th, 2022

The Department of Water Resources (DWR) is pleased to provide the following recommendations developed in response to the 2018 Legislation (Senate Bill 606 [Hertzberg] and

The Department of Water Resources (DWR) is pleased to provide the following recommendations developed in response to the 2018 Legislation (Senate Bill 606 [Hertzberg] and Assembly Bill 1668 [Friedman]) enacted in support of “Making Water Conservation a California Way of Life.” The Legislation included provisions for advancing urban water use efficiency through developing and implementing various water use efficiency standards, variances for unique uses of water, and commercial, industrial, and institutional (CII) performance measures, among other requirements. Full reports detailing our methods, technical analyses, studies, public input, and recommendations will follow. These recommendations for long-term urban water use efficiency reflect technical considerations, public input, and the imperative to continue California’s progress in urban efficient use of water for future generations. If adopted DWR's recommendations on outdoor residential and CII water use on landscapes with dedicated irrigation meters, combined with the indoor residential water use standard recommendations submitted to the Legislature jointly by DWR and State Water Resources Control Board (State Water Board), pursuant to Water Code 10609.4 (b)(1), would result in expected long-term water savings of approximately 450,000 acre-feet per year starting in 2030 – considering 2019 population and 2017-2019 water use data, the water savings are enough to supply about 1.6 million homes or 4.7 million residents for both indoor and outdoor annual water needs.

Record-Setting Ocean Warmth Continued in 2019

Advances in Atmospheric Sciences (Springer) | February 1st, 2020

Human-emitted greenhouse gases (GHGs) have resulted in a long-term and unequivocal warming of the planet (IPCC, 2019). More than 90% of the excess heat is stored within

Human-emitted greenhouse gases (GHGs) have resulted in a long-term and unequivocal warming of the planet (IPCC, 2019). More than 90% of the excess heat is stored within the world’s oceans, where it accumulates and causes increases in ocean temperature (Rhein et al., 2013; Abram et al., 2019). Because the oceans are the main repository of the Earth’s energy imbalance, measuring ocean heat content (OHC) is one of the best ways to quantify the rate of global warming (Trenberth et al., 2016; Von Schuckmann et al., 2016; Cheng et al., 2018). Following reports released in the previous two years (Cheng and Zhu, 2018; Cheng et al., 2019c), this article presents new OHC data for the year 2019. These data reveal that the world’s oceans (especially the upper 2000 m) in 2019 were the warmest in recorded human history. Specifically, the ocean heat anomaly (0−2000 m) in 2019 was 228 Zetta Joules (ZJ, 1 ZJ=1021 Joules) above the 1981−2010 average and 25 ZJ above 2018 (Table 1). The OHC values (for the upper 2000 m) were obtained from the Institute of Atmospheric Physics (IAP) ocean analysis (see “Data and methods” section, below), which uses a relatively new method to treat data sparseness and updates in the instruments that have been used to measure ocean temperature (Cheng et al., 2017). The evolution of OHC (Fig. 1) shows that the upper 2000 m OHC in 2019 was 228 ± 9 ZJ above the 1981–2010 average. The record-setting ocean warmth is also found in National Oceanic and Atmospheric Administration/National Center for Environmental Information (NOAA/NCEI) data, showing 217± 4 ZJ in 2019 above the 1981−2010 average (21 ZJ above 2018) (Table 1) (updated from Levitus et al. 2012). With these newly available IAP data, a ranking of the warmest years since the 1950s is now possible (Table 1). The past five years are the top five warmest years in the ocean historically with modern instruments, and the past ten years are also the top ten years on record. The same ranking also applies to NOAA/NCEI data (Table 1).

Redefining expectations for urban water supply systems to fight wildfires

Springer Nature | March 5th, 2025

When considering massive new costs for urban water systems to fight wildfires, we also need to look hard at the distribution of benefits from these investments, and desig

When considering massive new costs for urban water systems to fight wildfires, we also need to look hard at the distribution of benefits from these investments, and design legal and fiscal cost recovery mechanisms that align with those benefits. In the service area for the Los Angeles Department of Water and Power, greatly expanding capacity for water supply and fire-flow for the highest-elevation areas of the city would be delivering a benefit to communities that are much wealthier, on average, than the rest of the city. There is danger of placing a burden on less-resourced households to pay for the protection of well-resourced households, which would compound existing and profound environmental inequities in the city.

Regional monitoring programs in the United States: Synthesis of four case studies from Pacific, Atlantic, and Gulf Coasts

Regional Studies in Marine Science (Elsevier) | November 17th, 2015

Water quality monitoring is a cornerstone of environmental protection and ambient monitoring provides managers with the critical data they need to take informed action. U

Water quality monitoring is a cornerstone of environmental protection and ambient monitoring provides managers with the critical data they need to take informed action. Unlike site-specific monitoring that is at the heart of regulatory permit compliance, regional monitoring can provide an integrated, holistic view of the environment, allowing managers to obtain a more complete picture of natural variability and cumulative impacts, and more effectively prioritize management actions. By reviewing four long-standing regional monitoring programs that cover portions of all three coasts in the United States–Chesapeake Bay, Tampa Bay, Southern California Bight, and San Francisco Bay–important insights can be gleaned about the benefits that regional monitoring provides to managers. These insights include the underlying reasons that make regional monitoring programs successful, the challenges to maintain relevance and viability in the face of ever-changing technology, competing demands and shifting management priorities. The lessons learned can help other managers achieve similar successes as they seek to establish and reinvigorate their own monitoring programs.

Relative risk of groundwater-quality degradation near California (USA) oil fields estimated from 3H, 14C, and 4He

Applied Geochemistry (Elsevier) | June 5th, 2021

 Relative risks of groundwater-quality degradation near selected California oil fields are estimated by examining spatial and temporal patterns in chemical and isotopic

 Relative risks of groundwater-quality degradation near selected California oil fields are estimated by examining spatial and temporal patterns in chemical and isotopic data in the context of groundwater-age categories defined by tritium and carbon-14. In the Coastal basins, western San Joaquin Valley (SJV), and eastern SJV; 82, 76, and 0% of samples are premodern (pre-1953 recharge), respectively; and 3, 0, and 31% are modern (recharged during or after 1953), respectively. Carbon-14 and helium-4 data indicate most premodern samples are 1000 to 10,000 (33%) or >10,000 (50%) years old. Organic chemicals that could be associated with deeper hydrocarbon reservoirs (e.g. thermogenic gases and benzene) occur most frequently in premodern groundwater, suggesting premodern groundwater has a higher risk of degradation from upward migration of hydrocarbons than modern and mixed-age groundwater. Low sulfate concentrations in some premodern groundwater containing high thermogenic-methane concentrations (>28 mg/L) indicate methane attenuation associated with sulfate reduction can be limited in premodern groundwater. The more common occurrence of manufactured compounds, like tetrachloroethene, in modern and mixed-age groundwater than in premodern groundwater indicates modern and mixed-age groundwater has a higher risk of degradation from land-surface sources than premodern groundwater. Time-series data for chloride in groundwater affected by disposal of oil-field water in unlined ponds indicate some modern and mixed-age groundwater are susceptible to chemical migration within 2–3 km of surface sources. Timescales for diluting chloride concentrations in groundwater with fresh recharge once disposal ponds are decommissioned are shorter in mixed-age groundwater with large fractions of modern water (9–14 years in one example) than in mixed-age groundwater with large fractions of premodern water (no evidence of dilution after 12 years of monitoring in one example). The presence of predominantly premodern groundwater in the Coastal basins and western SJV indicates these areas have relatively high risk from upward migration of hydrocarbons, reduced methane attenuation capacity, and long dilution times, whereas predominantly modern-and mixed-age groundwater in the eastern SJV indicates this area has relatively high risk from chemical migration from land-surface sources and subsequent extensive spreading. Age-based characterizations of relative risk could inform the design of groundwater-monitoring programs near oil fields in terms of the spatial distribution of monitoring points relative to source areas and monitoring frequency and duration. 

Report Card for California's Infrastructure 2019

American Society of Civil Engineers (ASCE) | May 9th, 2019

Report of the Commissioners of Fisheries for the State of California for the Years 1883-4

State of California | January 31st, 1885

Report of the Commissioners of Fisheries of the State of California for the Year 1880

State of California | January 31st, 1881

Report of the Commissioners of Fisheries of the State of California for the Years 1870 and 1871

State of California | January 31st, 1872

Report of the Commissioners of Fisheries of the State of California for the Years 1872 and 1873

California Fish and Game Commission | January 30th, 1874