South Coast

Socio‐ecohydrology and the urban water challenge

Ecohydrology (Wiley) | March 11th, 2011

Urban water systems are highly engineered. However, hydrology and ecology are still closely linked in semi‐arid urban ecosystems in which surface characteristics, veget

Urban water systems are highly engineered. However, hydrology and ecology are still closely linked in semi‐arid urban ecosystems in which surface characteristics, vegetation, and water flows are all highly transformed. Although these systems are human‐dominated, there are many uncertainties in the water budgets of semi‐arid cities, because evapotranspiration, runoff, groundwater recharge, and leakage are poorly constrained. Decision‐making, governance, and socioeconomic factors play important roles in determining urban hydrologic budgets. We offer a framework to integrate these factors in studies that combine biophysical and social dimensions of the urban water system using the example of western US cities, which are facing critical issues in water supply and demand, and which can benefit from a more comprehensive understanding of the factors that determine water consumption, distribution and availability. Because of the severity of the water crisis in the western US, and the biophysical, institutional, and cultural barriers to developing and implementing new water management practices, this region provides useful lessons for addressing water challenges in other regions.

Source, Movement, and Age of Ground Water in a Coastal California Aquifer

U.S. Geological Survey (USGS) | July 11th, 1996

Understanding the contribution of recharge from different sources is important to the management of ground-water supply in coastal aquifers in California especial

Understanding the contribution of recharge from different sources is important to the management of ground-water supply in coastal aquifers in California especially where water-supply or water-quality problems have developed as a result of ground-water pumping. In areas where water levels have changed greatly as a result of pumping and no longer reflect predevelopment conditions, an analysis of isotopic data can provide information about the source, movement, and age of ground water that is not readily obtained from a more traditional analysis of ground-water data This information can be used to develop management strategies that incorporate the availability of natural and artificial recharge to control water-level declines and water-quality degradation. In this study, the ratios of the stable isotopes of oxygen and hydrogen were used to determine the source and trace the movement of ground water in the Santa Clara-Calleguas basin, Ventura County, California Tritium and carbon-14 data were used to estimate the age (time since recharge) of ground water.

South Coast Hydrologic Region Groundwater Update

California Department of Water Resources (DWR) | April 1st, 2015

The primary goal of the South Coast Hydrologic Region (South Coast region) groundwater update is to expand information about region-specific groundwater conditions for Ca

The primary goal of the South Coast Hydrologic Region (South Coast region) groundwater update is to expand information about region-specific groundwater conditions for California Water Plan Update 2013 and to guide more informed groundwater management actions and policies. A second goal is to steadily improve the quality of groundwater information in future California Water Plan (CWP) updates to a level that will enable regional water management groups (RWMGs) to accurately evaluate their groundwater resources and implement management strategies that can meet local and regional water resource objectives within the context of broader statewide objectives. The final goal is to identify data gaps and groundwater management challenges that will guide prioritizing of future data collection and funding opportunities relevant to the region. This regional groundwater update is not intended to provide a comprehensive and detailed examination of local groundwater conditions, or be a substitute for local studies and analysis. Nonetheless, where information is readily available, this update does report some aspects of the regional groundwater conditions in greater detail.

South-Central California Coast Steelhead Recovery Plan

National Marine Fisheries Service (NMFS) | December 19th, 2013

The goal of this Recovery Plan is to prevent the extinction of South-Central California Coast steelhead (Oncorhynchus mykiss) in the wild and to ensure the long-term pers

The goal of this Recovery Plan is to prevent the extinction of South-Central California Coast steelhead (Oncorhynchus mykiss) in the wild and to ensure the long-term persistence of viable, self-sustaining, populations of steelhead distributed across the South-Central California Coast Steelhead (SCCCS) Distinct Population Segment (DPS). It is also the goal of this Recovery Plan to ensure a sustainable South-Central California steelhead sport fishery through the restoration of a suite of viable steelhead populations across the SCCCS DPS. Recovery of the SCCCS DPS will require the protection, restoration, and maintenance of a range of habitats throughout the DPS in order to allow the natural diversity of O. mykiss to be fully expressed (e.g., anadromous and resident forms, timing and frequency of runs, and dispersal between watersheds).

Southern California winter precipitation variability reflected in 100-year ocean salinity record

Nature Portfolio (Springer Nature) | April 27th, 2023

Rainfall in southern California is highly variable, with some fluctuations explainable by climate patterns. Resulting runoff and heightened streamflow from rain events in

Rainfall in southern California is highly variable, with some fluctuations explainable by climate patterns. Resulting runoff and heightened streamflow from rain events introduces freshwater plumes into the coastal ocean. Here we use a 105-year daily sea surface salinity record collected at Scripps Pier in La Jolla, California to show that El Niño Southern Oscillation and Pacific Decadal Oscillation both have signatures in coastal sea surface salinity. Averaging the freshest quantile of sea surface salinity over each year’s winter season provides a useful metric for connecting the coastal ocean to interannual winter rainfall variability, through the influence of freshwater plumes originating, at closest, 7.5 km north of Scripps Pier. This salinity metric has a clear relationship with dominant climate phases: negative Pacific Decadal Oscillation and La Niña conditions correspond consistently with lack of salinity anomaly/ dry winters. Fresh salinity anomalies (i.e., wet winters) occur during positive phase Pacific Decadal Oscillation and El Niño winters, although not consistently. This analysis emphasizes the strong influence that precipitation and consequent streamflow has on the coastal ocean, even in a region of overall low freshwater input, and provides an ocean-based metric for assessing decadal rainfall variability.

Spring 2017 Groundwater Level Data Summary

California Department of Water Resources (DWR) | October 3rd, 2022

This document presents a summary of fall 2017 groundwater level data available in the DWR groundwater level database as of February 21, 2018 and includes a discussion of

This document presents a summary of fall 2017 groundwater level data available in the DWR groundwater level database as of February 21, 2018 and includes a discussion of fall 2017, data coverage and groundwater level trends. Statewide precipitation data come from the U.S. Climate Divisional Database, which has data from January 1895 to the present.

Stacked Incentives: Co-Funding Water Customer Incentive Programs

Pacific Institute | June 1st, 2021

Water utilities throughout the United States offer customer incentives to motivate action and foster engagement. Incentive programs can take many forms, such as rebate

Water utilities throughout the United States offer customer incentives to motivate action and foster engagement. Incentive programs can take many forms, such as rebates for high-efficiency fixtures and appliances, technical assistance for installing cisterns and rain gardens, and educational programs about water reuse. In addition to providing water-related benefits, many of these programs generate additional co-benefits, including reductions in energy use for heating or treating water and wastewater, increased carbon sequestration in landscapes, enhancements to local biodiversity, and more. These co-benefits present water utilities with an opportunity to build collaborative partnerships and co-funding for customer incentive programs through “stacked incentives.”

Standardized Regulatory Impact Assessment of Proposed Making Conservation a California Way of Life Regulation

California State Water Resources Control Board (SWRCB) | June 21st, 2024

Water conservation in California overall, due to the proposed regulation and other conservation efforts by water suppliers and Californians generally, plus passive conser

Water conservation in California overall, due to the proposed regulation and other conservation efforts by water suppliers and Californians generally, plus passive conservation from prior conservation efforts, is estimated to save levels of water consistent with the goal mentioned in the Water Supply Strategy of the reduction of the water demand of towns and cities by half a million acre-feet per year. The proposed regulation serves as a backstop that is expected to cause new savings and “lock in” these other savings. As shown in the graph below, staff estimated that the proposed regulation would save approximately 30,000 acre-feet of water in 2027 (compared to the assumed 2027 baseline water use) and increased amounts in subsequent years, reaching almost 235,000 acre-feet of water in 2050 (compared to the assumed 2050 baseline water use). The total cumulative amount of water savings in the 2025-2050 period would be approximately 3.9 million acre-feet. More than half of the estimated water savings (approximately 52 percent) would come from the assumed residential water conservation measures, and the remainder (approximately 48 percent) from CII (Commercial, Industrial, and Institutional) performance measures.

State of California Department of Natural Resources Division of Fish and Game Thirtieth Biennial Report 1926-1928

State of California | September 30th, 1928

State of California Department of Natural Resources Fortieth Biennial Report of the Division of Fish and Game for the Years 1946-1948

State of California | July 1st, 1948