LA Sustainable Water Project: Los Angeles City-Wide Overview

University of California, Los Angeles (UCLA) | February 1st, 2018

This report assesses the potential to improve water quality standards while integrating complementary One Water Management practices that can increase potential local wat

This report assesses the potential to improve water quality standards while integrating complementary One Water Management practices that can increase potential local water supplies for the City of Los Angeles (the City).  This final report summarizes the current practices and future opportunities at the City-owned Water Reclamation Plants and underlying groundwater basins and highlights the importance of considering all aspects of integrated water management even when dealing with water quality or supply-focused projects. Implementing watershed-scale best management practice programs to meet stormwater permit requirements will significantly improve water quality in all watersheds.  However, additional mechanisms such as increasing Low Impact Development implementation and comprehensive source tracking and source control mechanisms will be required to potentially eliminate water quality exceedances.  There are multiple efforts occurring in the City and the region to increase the recharge of recycled water into the ground and the volumes of remediated groundwater extracted. This research further assessed the impacts of potential water supply portfolios, with greater volumes of locally-supplied water, on GHG emissions and energy needs of supplying LA’s water.  Conservation will be another powerful tool to decrease our dependence on imported water.  This research demonstrates the complex interrelationships between all aspects of urban water management, including, for example, stormwater management and local water supply.

LA Sustainable Water Project: Los Angeles River Watershed

University of California, Los Angeles (UCLA) | September 1st, 2017

The LA Sustainable Water Project: Los Angeles River Watershed report explores the potential to improve water quality standards while integrating complementary One Water M

The LA Sustainable Water Project: Los Angeles River Watershed report explores the potential to improve water quality standards while integrating complementary One Water Management practices that can increase potential local water supplies for the City of Los Angeles (the City) in the highly urbanized Los Angeles River (LAR) watershed.To assess the integrated water landscape in this watershed, the report also looks at current practices and future opportunities at the Donald C Tillman, LA Glendale, and Burbank Water Reclamation Plants (WRPs) and in the underlying Upper LA River Area (ULARA) adjudicated groundwater basins. Implementing watershed-scale best management practice programs to meet stormwater permit requirements will significantly improve water quality. However, additional mechanisms such as increasing Low Impact Development implementation and comprehensive source tracking and source control mechanisms will be required to potentially eliminate water quality exceedances. The 3 WRPs in the watershed currently discharge more than 30 million gallons per day of treated wastewater into the River; an increased focus on increasing local water supply could lead to a reduction in these discharges. The combination of increased stormwater capture and increased use of recycled water in the LAR watershed could lead to lower flows in the LAR and impact habitat and recreational uses; further study is needed to characterize potential impacts and identify optimal flows for the future of the LAR. The City is leading efforts in ULARA to increase the recharge of recycled water into theground by 30,000 acre feet per year and increase the volumes of remediated groundwater extracted by around 120,000 acre feet per year. This research demonstrates the complex interrelationships between all aspects of urban water management, including stormwater management and local water supply.

Lake Tahoe Nearshore Water Quality Protection Plan

California State Water Resources Control Board (SWRCB) | November 6th, 2014

In October 2013, the Desert Research Institute, UC Davis, and University of Nevada at Reno released the Lake Tahoe Nearshore Evaluation and Monitoring Framework Report (R

In October 2013, the Desert Research Institute, UC Davis, and University of Nevada at Reno released the Lake Tahoe Nearshore Evaluation and Monitoring Framework Report (Report) (NeST 2013). The Report presents a conceptual understanding of nearshore environment processes, assesses the heterogenic nature of the nearshore, highlights the lack of data available to characterize the environmental status of the Lake Tahoe nearshore, and emphasizes that current agency implementation efforts will benefit the nearshore environment. This Lake Tahoe Nearshore Water Quality Protection Plan (Plan) outlines the Lahontan Regional Water Quality Control Board’s (Regional Water Board) response to the changes in the Lake Tahoe nearshore environment as informed by the Report. Based on the Report findings and recommendations, the Regional Water Board will proceed with the following actions: (1) continue implementing programs that benefit nearshore environmental quality; (2) establish and implement an integrated nearshore monitoring plan to track change in the nearshore environment and track pollutant inputs to the nearshore; (3) evaluate localized “hotspots” where nearshore change has been documented and assess causes of observed degradation; (4) investigate climate change influence on nearshore water quality; and (5) assess the need for revised or new water quality standards to protect nearshore water quality. In establishing and maintaining nearshore water quality protection policies, the Water Board will continue to coordinate with other government agencies and the public. Because available resources are insufficient to fully implement all recommendations, a dedicated annual funding source must be found to adequately protect and enhance Lake Tahoe’s precious nearshore. The Plan elements and funding needs are presented in Attachment 1. The Plan also serves as response to a Legislative request in the 2012-2013 Budget Act specific to the Water Board’s approach to the nearshore.

Land Subsidence in Santa Clara Valley, Alameda, San Mateo, and Santa Clara Counties California

U.S. Geological Survey (USGS) | January 31st, 1971

Land use and land cover influence on water quality in the last free-flowing river draining the western Sierra Nevada, California

Journal of Hydrology (Elsevier) | November 10th, 2005

Land use and land cover across 28 sub-basins within the Cosumnes Watershed, CA (1989 km2) were correlated to nitrate-N and total suspended solids (TSS) loading between w

Land use and land cover across 28 sub-basins within the Cosumnes Watershed, CA (1989 km2) were correlated to nitrate-N and total suspended solids (TSS) loading between water years 1999 and 2001. The impact of human development on stream water quality was evident as both agricultural area and population density predicted TSS loading in a linear mixed effects model. In contrast to the TSS model, the nitrate-N loading model was more complex with agriculture, grassland, and the presence or absence of waste water treatment plants (WWTPs) all contributing. The lack of correlation between population density and nitrate-N loading indicates that human habitation of the landscape does not impact stream nitrate levels until a WWTP is built within the sub-basin. During dry water years the models predict a linear reduction in TSS loading but the correlations to agriculture and population density remain positive. In contrast, nitrate is positively correlated to grasslands during average water years and negatively correlated during dry water years. Analysis of constituent fluxes from the upper watershed versus the lower watershed indicates that silica is derived primarily from the uplands and that during dry water years the upper watershed is an important source of dissolved organic carbon (DOC) and nitrate. The lower watershed contributes the majority of the sediment and nutrients during both dry and average water years, the one caveat being that during dry years the lower basin becomes a nitrate sink.

Land Use and Water Quality on California’s Central Coast: Nutrient Levels in Coastal Waterways

University of California, Santa Cruz (UC Santa Cruz) | July 17th, 2003

Increased focus on addressing non-point source (NPS) pollution throughout the U.S. has raised awareness of agriculture’s impact on water quality. Growers are being a

Increased focus on addressing non-point source (NPS) pollution throughout the U.S. has raised awareness of agriculture’s impact on water quality. Growers are being asked to voluntarily limit the effects of their operations on adjacent waterways through programs such those initiated by county Farm Bureaus. If pollution cannot be voluntarily controlled, growers may face mandatory regulatory actions in the future. Maintaining water quality is an ongoing challenge in the Monterey Bay watershed, where industry, urban development, and farming all affect sensitive waterways. Excess nitrogen and phosphorous, herbicides, insecticides, and sediments that end up in sloughs and wetlands surrounding Monterey Bay have compromised water quality, contaminated shellfish, birds, and other wildlife, and generated unsafe levels of nitrate in drinking water.  Although nutrient contamination is well recognized, to date there have been few efforts to link water quality with land uses such as urban development and farming in the region. To determine the way that land uses affect nitrogen and phosphorous concentrations in central coast waterways, researchers Marc Los Huertos, Lowell Gentry, and Carol Shennan have monitored water flow and sampled water quality in the Pajaro River and in other Pajaro Valley and Elkhorn Slough watershed creeks and agricultural drainages, for the past two water years (October 2000–September 2002). The research takes place through the UC Santa Cruz Center for Agroecology and Sustainable Food Systems (the Center) and is part of a larger U.S. Department of Agriculture grant awarded to Center director Shennan. This water quality monitoring program was developed in cooperation with the Santa Cruz County Farm Bureau, local Resource Conservation Districts, and other groups.  We are particularly interested in the concentrations of two nutrients, nitrogen (nitrate-N) and phosphorus (ortho-P, also known as soluble reactive phosphorus), that are components of non-point source (NPS) pollution originating from urban and agricultural land uses.

Land Use, Pollutants, and Water Quality in California Streams

California State Water Resources Control Board (SWRCB) | April 12th, 2012

A number of spatial patterns were evident in this survey of watersheds from throughout California. Stream sediment concentrations of heavy metals, such as cadmi

A number of spatial patterns were evident in this survey of watersheds from throughout California. Stream sediment concentrations of heavy metals, such as cadmium, copper, lead and zinc, tended to be highest in urbanized Los Angeles and San Francisco Bay area watersheds. Metal concentrations in sediments from San Leandro Creek (SF Bay area), Ballona Creek and San Gabriel River (Los Angeles area) were among the highest in the state. These metals are released to the environment from brake pads, plumbing, industrial and commercial activities. Industrial organic compounds such as PCBs (banned since the 1970s), PBDEs (flame retardants) and PAHs (hydrocarbons) were also generally highest in stream sediments from the Los Angeles and San Francisco Bay areas, though high concentrations were also measured in some more remote locations. In contrast to this urban pattern, mercury concentrations were highest in sediments from watersheds where it is geologically abundant and historically mined, though some urban streams also had relatively high mercury levels. The persistent legacy pesticide DDT was found in stream sediments from most urban and agricultural watersheds, where recent soil disturbance from development and tillage likely mobilizes DDT residues from applications more than 40 years ago. Pyrethroid pesticides are increasing in use in California and were detected in 55% of the samples statewide (51 of 92). The highest pyrethroid concentrations were measured in sediments collected from urban watersheds, plus two agricultural watersheds along the central coast. Approximately one quarter of the sediment samples collected were significantly toxic to amphipods, which are resident crustaceans representative of important aquatic food web links. Of these samples, 6.5% were identified as highly toxic. The highly toxic samples were collected from agricultural watersheds in the Tulare basin and central coast, in urban areas of southern California, and in the Tijuana River. Other toxic samples were collected from a wide range of watershed types, including those along the north coast, the Tahoe area, and urban and agricultural areas across the state. On a statewide basis, watersheds with greater than 10% urban land cover had consistently higher sediment pollutant concentrations and toxicity than did watersheds characterized by agricultural or other land cover types. Metals, industrial compounds, DDTs, and pyrethroid pesticides were all found at significantly higher concentrations in urban streams. This pattern is evident at the statewide level, but other local and regional studies have previously shown that pollution levels and toxicity can be strongly related to agricultural and other land uses in specific areas. This is because the “agricultural” land use category used in the SPoT analysis is comprised of many different types of crops and farming practices, and the amount of polluted runoff from these lands varies depending on the types of practices employed.

Land-use interactions, Oil-Field infrastructure, and natural processes control hydrocarbon and arsenic concentrations in groundwater, Poso Creek Oil Field, California, USA

Elsevier | May 7th, 2024

Latitudinal gradients of snow contamination in the Rocky Mountains associated with anthropogenic sources

Elsevier | March 26th, 2025

Seasonal snow is an important source of drinking water and recreation, and for agriculture in the Rocky Mountain region. Monitoring snow-water quality can inform on the e

Seasonal snow is an important source of drinking water and recreation, and for agriculture in the Rocky Mountain region. Monitoring snow-water quality can inform on the effects to the albedo and energy balance of the snowpack, and the sources of natural and anthropogenic aerosol and gases. This study analyzed metals in the seasonal snowpack from water year (WY) 2018 for 49 sites. Calcium, lanthanum, and cerium concentrations support the importance of mineral dust to the southern Rocky Mountains. Mercury (Hg), zinc (Zn), and cadmium (Cd) concentrations showed a similar spatial pattern to mineral dust, whereas antimony (Sb) concentrations were highest in the northern Rocky Mountains. To assess the relative contributions from dust versus anthropogenic contaminant sources, enrichment factors (EF) were calculated, with values above 10 indicating anthropogenic contamination. For Cd, Hg, Sb, and Zn, EF values exceeded 10 at northern sites. These observations were compared to spatial trends of EF values of Hg from WY2009 to WY2018, regional monitoring networks, and back trajectory analyses. The agreement between these datasets revealed temporally consistent contaminant sources and/or transport processes to the northern Rocky Mountains snowpack. Sources include current and historical mining and smelting in the region. Strategies to limit the emissions of these metals to the Northern Rockies could benefit from focusing on remediation of contaminated sites, and continued monitoring and mitigation of active mining and smelting.

Learning from California’s Experience with Small Water System Consolidations: A Workshop Synthesis

Center for Law, Energy, and the Environment (CLEE) | May 1st, 2018

California recognizes a human right to “safe, clean, affordable, and accessible water adequate for human consumption, cooking, and sanitary purposes.” However

California recognizes a human right to “safe, clean, affordable, and accessible water adequate for human consumption, cooking, and sanitary purposes.” However, California’s small and disadvantaged communities in both rural and urban contexts can find it especially challenging to fund the water system infrastructure, operations, monitoring, and maintenance necessary to achieve this goal.  Small water systems that provide water to at least 15 service connections and serve water to fewer than a thousand people are responsible for the bulk of the state’s drinking water quality violations, and an estimated 300 disadvantaged communities in California are served by systems that fail to meet state drinking water standards. Other Californians rely on very small water systems or private domestic wells that lack state requirements for water quality testing and may be especially unreliable.