Memorandum of Understanding by and among Colorado River Basin Municipal and Public Water Providers

Southern Nevada Water Authority (SNWA) | November 15th, 2022

Methodologies for Calculating Baseline and Compliance Urban Per Capita Water Use (For the Consistent Implementation of the Water Conservation Act of 2009)

California Department of Water Resources (DWR) | April 26th, 2016

In November 2009, SBX7-7, The Water Conservation Act of 2009, was signed into law as part of a comprehensive water legislation package. The Water Conservation Act address

In November 2009, SBX7-7, The Water Conservation Act of 2009, was signed into law as part of a comprehensive water legislation package. The Water Conservation Act addresses both urban and agricultural water conservation. The urban provisions reflect the approach taken in the 20x2020 Water Conservation Plan. The legislation sets a goal of achieving a 20-percent statewide reduction in urban per capita water use and directs urban retail water suppliers to set 2020 urban water use targets. The Water Conservation Act of 2009 directs DWR to develop technical methodologies and criteria to ensure the consistent implementation of the Act and to provide guidance to urban retail water suppliers in developing baseline and compliance water use. To meet the legislative directives for consistent implementation, DWR has developed and published Methodologies for Calculating Baseline and Compliance Year Per Capita Water Use. This is the third revision of the Methodologies for Calculating Baseline and Compliance Urban per Capita Water Use. The document was first released in October 2010 and then revised in February 2011 with the addition of the Provisional Method 4 for Determining Water Use Targets as Appendix C. This revision includes Methodology 8: Criteria for Adjustments for Compliance Daily per Capita Water Use and removes the former Appendix A: Alternative Methodology for Service Area Population. Methodology 8 was not included in the earlier versions of the Methodologies as it was not required for the completion of the 2010 urban water management plans and more time was needed to thoroughly develop the methodology. The former Appendix A provided instructions for using the Census Bureau’s website to calculate service area population using a person per connection approach. The Census Bureau has revised its website and the links in the former document are no longer valid. Additionally, as part of its guidance for the 2015 UWMPs, DWR has included a population mapping tool as part of the on-line urban water management plan data submittal website. The population mapping tool provides a simpler and streamlined approach to estimating service area population.

Metropolitan Water Management

American Geophysical Union (AGU) | January 1st, 1981

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 6. This monograph is intended to inform interested and capable pers

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 6. This monograph is intended to inform interested and capable persons, who happen not to be specialists in water resources planning, of the issues and alternative strategies related to metropolitan water supply. This involves learning something about the alternative strategies—some ancient and others not yet operational—for increasing water supplies and/or modifying demand so a supply/demand balance is maintained. This also requires an awareness of the complex economic, environmental, and social issues that increasingly compound what once was considered a purely technological problem, to be left to water resource specialists to solve.

Modeling Cost, Energy, and Total Organic Carbon Trade-Offs for Stormwater Spreading Basin Systems Receiving Recycled Water Produced Using Membrane-Based, Ozone-Based, and Hybrid Advanced Treatment Trains

American Chemical Society (ACS) | January 31st, 2019

To address water scarcity, cities are pursuing options for augmenting groundwater recharge with recycled water. Ozone-based treatment trains comprising ozone and biologic

To address water scarcity, cities are pursuing options for augmenting groundwater recharge with recycled water. Ozone-based treatment trains comprising ozone and biologically activated carbon potentially offer cost-effective alternatives to membrane-based treatment, the standard process for potable reuse in numerous countries. However, regulations in multiple states effectively limit the extent to which ozone-based treatment alone can produce recycled water for groundwater recharge. To investigate the trade-offs between treatment costs and regulatory constraints, this study presents methods for modeling and optimizing designs for (1) producing recycled water using membrane-based treatment, ozone-based treatment, and hybrid treatment trains comprising ozone-based treatment with a membrane sidestream, and (2) delivering that water to stormwater spreading basins. We present a case study of Los Angeles, CA, to demonstrate the model’s application under realistic conditions, including regulations that limit spreading recycled water based on its concentration of total organic carbon and the extent of dilution. While the membrane-based treatment train exhibits economies of scale, we demonstrate how regulatory constraints create a diseconomies of scale effect for hybrid treatment systems because larger scales necessitate a higher proportion of recycled water undergo membrane treatment. Nevertheless, relative to membrane-based treatment, we identify opportunities for ozone-based or hybrid treatment trains to reduce treatment costs and energy use by up to 62% and 59%, respectively, for systems with up to 1 m3/s (23 million gallons per day) mean water recycling rate, potentially lowering the barrier for decentralized water recycling systems. This modeling approach could inform planning and policy regarding recycled water projects for groundwater recharge through spreading basins and, with additional modification, other potable reuse applications.

Monitoring of Drought Awareness from Google Trends: A Case Study of the 2011–17 California Drought

American Meteorological Society (AMS) | April 1st, 2019

Moving Toward a Multi-Benefit Approach for Water Management

Pacific Institute | April 11th, 2019

There is broad recognition that adapting to climate change, coupled with the need to address aging infrastructure, population growth, and degraded ecosystems, will re

There is broad recognition that adapting to climate change, coupled with the need to address aging infrastructure, population growth, and degraded ecosystems, will require rethinking programs and policies and investing in our natural and built water systems. There are a variety of strategies for addressing water challenges, from watershed restoration and efficiency improvements to vegetated swales and green roofs. Because water is deeply linked with economic, environmental, and community wellbeing, many of these strategies can also provide other benefits, such as reducing energy use and greenhouse gas emissions, providing wildlife habitat, and enhancing community livability.

Multiyear Water Quality Performance and Mass Accumulation of PCBs, Mercury, Methylmercury, Copper, and Microplastics in a Bioretention Rain Garden

American Society of Civil Engineers (ASCE) | November 1st, 2019

A multiyear water quality performance study of a bioretention rain garden located along a major urban transit corridor east of San Francisco Bay was conducted to assess t

A multiyear water quality performance study of a bioretention rain garden located along a major urban transit corridor east of San Francisco Bay was conducted to assess the efficacy of bioretention rain gardens to remove pollutants. Based on data collected in three years between 2012 and 2017, polychlorinated biphenyls (PCBs) and suspended sediment concentrations (SSCs) were reduced (>90%>90%), whereas total mercury (Hg), methylmercury (MeHg), and copper (Cu) were moderately captured (37%, 49%, and 68% concentration reduction, respectively). Anthropogenic microparticles including microplastics were retained by the bioretention rain garden, decreasing in concentration from 1.6particles/L1.6  particles/L to 0.16particles/L0.16  particles/L. Based on subsampling at 50- and 150-mm intervals in soil cores from two areas of the unit, PCBs, Hg, and MeHg were all present at the highest concentrations in the upper 100 mm in the surface media layers. Based on residential screening concentrations, the surface media layer near the inlet would need to be removed and replaced annually, whereas the rest of the unit would need replacement every 8 years. The results of this study support the use of bioretention in the San Francisco Bay Area as one management option for meeting load reductions required by San Francisco Bay total maximum daily loads, and provide useful data for supporting decisions about media replacement and overall maintenance schedules.

Municipal Deliveries of Colorado River Basin Water: New Report Examines 100 Cities and Agencies

Pacific Institute | June 12th, 2011

The Pacific Institute’s Municipal Deliveries of Colorado River Basin Water documents population and water delivery information and trends for 100 cities and agencies th

The Pacific Institute’s Municipal Deliveries of Colorado River Basin Water documents population and water delivery information and trends for 100 cities and agencies that deliver water from the Colorado River basin. Since 1990, the number of people in the United States and Mexico who use Colorado River basin water has increased by more than 10 million -– but their overall per capita water use declined by an average of at least one percent per year from 1990 to 2008. The new report provides -– for the first time -– real numbers on the extraordinary population growth among cities that depend on water from the basin and on changing water delivery rates by these cities. Author Michael Cohen, senior research associate, documents the substantial water-efficiency gains made over the past twenty years by agencies delivering water from the Colorado River basin -– even by agencies and cities such as Flagstaff that already had relatively low per capita delivery rates in 1990.

Navigating Transformations in 2023: The Metropolitan Water District of Southern California Year in Review

Metropolitan Water District of Southern California (MWD) | April 13th, 2024

One Water LA 2040 Plan

City of Los Angeles | April 30th, 2018

The purpose of the One Water LA 2040 Plan (Plan) is to increase sustainable water management for the City of Los Angeles (City). The City launched One Water LA with two p

The purpose of the One Water LA 2040 Plan (Plan) is to increase sustainable water management for the City of Los Angeles (City). The City launched One Water LA with two primary goals: 1. Develop a vision and implementation strategy to more sustainably and cost-effectively manage water. 2. Identify ways for City departments and regional agencies to integrate their water management strategies. Los Angeles Sanitation (LASAN) and the Los Angeles Department of Water and Power (LADWP) led the Plan's development, partnering with other City departments, regional agencies, academia, the business community, and other stakeholders. The Plan provides a comprehensive strategy for managing water in a more integrated, collaborative, and sustainable way through new project, program, and policy opportunities. The Implementation Strategy provides a roadmap to make the One Water LA Vision a reality. Additional water projects, programs, or policies that are the sole responsibility of one agency, including LADWP's aqueduct or groundwater remediation project, are contained in each agency's appropriate plans. This plan is divided into an Executive Summary and ten sections. Executive Summary Volume One: Summary Report Volume Two: Wastewater Facilities Plan Volume Three: Stormwater and Urban Runoff Facilities Plan Volume Four: Los Angeles River Flow Study Volume Five: Integration Opportunities Analysis Volume Six: Climate Risk and Resilience Assessment for Wastewater and Stormwater Infrastructure Volume Seven: Implementation Strategy Supporting Documents Volume Eight: Technical Support Materials Volume Nine: Stakeholder Engagement Materials, Part 1, Part 2, Part 3 Volume Ten: Programmatic Environmental Impact Report (in progress)