Green Light for Adaptive Policies on the Colorado River

Water (MDPI) | December 21st, 2021

The Colorado River is a critical source of water supply for 40 million people in nine states spanning two nations in western North America. Overallocated in the 20th cent

The Colorado River is a critical source of water supply for 40 million people in nine states spanning two nations in western North America. Overallocated in the 20th century, its problems have been compounded by climate change in the 21st century. We review the basin’s hydrologic and water management history in order to identify opportunities for adaptive governance to respond to the challenge of reduced system flows and distill the ingredients of past successes. While significant advances have been made in the first two decades of the 21st century, these past actions have not been sufficient to halt the declines in the basin’s reservoirs. We find that the mix of federal, state, and local responsibility creates challenges for adaptation but that progress can be made through a combination of detailed policy option development followed by quick action at hydrologically driven moments of opportunity. The role of directives and deadlines from federal authorities in facilitating difficult compromises is noted. The current state of dramatically decreased overall flows has opened a window of opportunity for the adoption of water management actions that move the river system toward sustainability. Specific measures, based on the existing institutional framework and on policy proposals that have circulated within the Colorado River community, are suggested.

Greenhouse Gas Emissions Calculator for the Water Sector: User’s Manual

U.S. Bureau of Reclamation (USBR) | September 24th, 2013

The Santa Ana Watershed Basin Study (Basin Study) is a collaborative effort by the Santa Ana Watershed Project Authority (SAWPA) and the Bureau of Reclamation (Reclamatio

The Santa Ana Watershed Basin Study (Basin Study) is a collaborative effort by the Santa Ana Watershed Project Authority (SAWPA) and the Bureau of Reclamation (Reclamation), authorized under the Sustain and Manage America's Resources for Tomorrow SECURE Water Act (Title IX, Subtitle F of Public Law 111-11). The Basin Study complements SAWPA’s Integrated Regional Water Management (IRWM) planning process, also known as their “One Water One Watershed” (OWOW) Plan. It refines the watershed’s water projections, and identifies potential adaptation strategies, in light of projected effects of climate change. The Climate Change Analysis for the Santa Ana River Watershed (SARW) is a contributing section to the Basin Study. The Greenhouse Gas (GHG) Emissions Calculator was developed as a tool to support the Climate Change Analysis. It was developed to evaluate mitigation strategies, while the Climate Change Analysis focused primarily on adaption and vulnerability analysis. Development of the tool began in 2012 and was completed in August 2013. This report explains the methods used to develop the calculator and provides instructions on how to use it by introducing examples. The examples focus on the SARW to show how to develop a GHG emissions baseline, evaluate what it would take to meet specific GHG emission reduction goals, and illustrate how the GHG Emissions Calculator can be used to analyze projects. Chapter 1 provides an introduction to the project, a literature review, and a summary of California’s GHG legislation. The methods used in the GHG Emissions Calculator can be found in Chapter 2. A guide showing users what data is needed and how to enter that data can be found in Chapter 3. Chapter 4 provides an introduction to the SARW, the GHG emission baseline for the SARW, discusses varies scenarios to reduce GHG emissions, and compares those reduction scenarios. In Chapter 5 SAWPA’s 20 finalist for the Integrated Regional Water Management (IRWM) funding were analyzed using the GHG Emissions Calculator. The GHG Emission Calculator is a decision-making tool that can be used to explore the links between water resources, energy, and GHG emissions. It can be used to determine water supply and energy demands for the study area, in addition to GHG emissions from 1990 to 2050. It can be used to analyze a study area ranging from a city block to an entire watershed, regardless of the level of detailed data available. The GHG Emissions calculator is a vital tool for decision makers when developing water supply plans for the future. It is also equipped to evaluate long term GHG emission reduction potential for new projects that will alter the water supply portfolio.

Greenhouse gas emissions from US irrigation pumping and implications for climate-smart irrigation policy

Nature Portfolio (Springer Nature) | January 23rd, 2024

Ground water and climate change

Nature Portfolio (Springer Nature) | November 25th, 2012

As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability a

As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

Groundwater microbiomes balance resilience and vulnerability to hydroclimatic extremes

Nature Portfolio (Springer Nature) | August 20th, 2025

Growing human-induced climate change fingerprint in regional weekly fire extremes

Nature Portfolio (Springer Nature) | April 23rd, 2025

Growing impact of wildfire on western US water supply

National Academy of Sciences (NAS) | February 22nd, 2022

Streamflow often increases after fire, but the persistence of this effect and its importance to present and future regional water resources are unclear. This paper addres

Streamflow often increases after fire, but the persistence of this effect and its importance to present and future regional water resources are unclear. This paper addresses these knowledge gaps for the western United States (WUS), where annual forest fire area increased by more than 1,100% during 1984 to 2020. Among 72 forested basins across the WUS that burned between 1984 and 2019, the multibasin mean streamflow was significantly elevated by 0.19 SDs (P < 0.01) for an average of 6 water years postfire, compared to the range of results expected from climate alone. Significance is assessed by comparing prefire and postfire streamflow responses to climate and also to streamflow among 107 control basins that experienced little to no wildfire during the study period. The streamflow response scales with fire extent: among the 29 basins where >20% of forest area burned in a year, streamflow over the first 6 water years postfire increased by a multibasin average of 0.38 SDs, or 30%. Postfire streamflow increases were significant in all four seasons. Historical fire–climate relationships combined with climate model projections suggest that 2021 to 2050 will see repeated years when climate is more fire-conducive than in 2020, the year currently holding the modern record for WUS forest area burned. These findings center on relatively small, minimally managed basins, but our results suggest that burned areas will grow enough over the next 3 decades to enhance streamflow at regional scales. Wildfire is an emerging driver of runoff change that will increasingly alter climate impacts on water supplies and runoff-related risks.

Guidance for Climate Change Data Use During Groundwater Sustainability Plan Development

California Department of Water Resources (DWR) | April 12th, 2018

This Guidance Document was developed to help Groundwater Sustainability Agencies (GSAs) incorporate California Department of Water Resources (DWR)-provided climate change

This Guidance Document was developed to help Groundwater Sustainability Agencies (GSAs) incorporate California Department of Water Resources (DWR)-provided climate change and related data into their Groundwater Sustainability Plans (GSPs). The purpose of this Guidance Document is as follows: • Provide relevant data and tools for GSAs to incorporate climate change into their GSPs. • Provide an analysis approach using the provided data and tools that incorporates the best available science and best available information to date. This Guidance Document focuses on the use of DWR-provided climate change data and provides documentation about the following: • Climate change data development approach • Climate change data development methods and processes • Applications for using the provided climate change data • Climate change data assumptions and limitations This Guidance Document provides a process for using DWR-provided climate change data for computing projected water budgets and serves as a companion document to the water budget best management practices (BMPs)2 and the modeling BMP3. For Sustainable Groundwater Management Act (SGMA) implementation purposes, the use of climate change data can help with the following: • Developing projected water budgets • Long-term planning of groundwater basin sustainability • Assessing projects and management actions by performing sensitivity analyses of projected conditions • Adaptive Management

Guide for Developing Onsite Water Systems to Support Regional Water Resilience

Pacific Institute | January 26th, 2023

Across the United States, urban communities face growing water challenges, from water scarcity to flooding, pollution, aging water infrastructure, and more. These challen

Across the United States, urban communities face growing water challenges, from water scarcity to flooding, pollution, aging water infrastructure, and more. These challenges present risks, but also an opportunity to rethink how we manage water, including adopting circular approaches in new buildings that reduce their water footprint and improve urban water resilience. Onsite water systems, for example, collect, treat, and reuse water from onsite sources, including wastewater, rainwater, and stormwater, for non-potable water uses like toilet flushing, outdoor irrigation, and cooling. Onsite water systems have the potential to provide multiple benefits for a site, water and wastewater systems, ecosystems, and communities. They can, for example, help companies mitigate water- related risks, like water shortages that threaten to disrupt business operations, and support corporate water stewardship goals. For communities, onsite water systems can enhance water supply reliability, improve water quality, reduce localized flooding, and increase urban green space. The realization and magnitude of benefits will vary with the type of system, scale of adoption, and other context-specific factors. This guide helps site developers consider how onsite water systems can be planned, designed, and operated to provide multiple benefits, and contribute to planning and designing onsite water systems that advance water resilience, support equity, support the environment, and protect public health at the site, water system, and community scales. For each of these outcomes, the guide provides sample questions to consider, stakeholders to engage, resources to examine, and analyses to perform.

Guidelines for Considering Traditional Knowledges in Climate Change Initiatives

California Department of Water Resources (DWR) | September 9th, 2014

This publication is meant to be an informational resource for tribes, agencies, and organizations across the United States with an interest in understanding Traditional K

This publication is meant to be an informational resource for tribes, agencies, and organizations across the United States with an interest in understanding Traditional Knowledges (TKs) in the context of climate change. It is meant to inspire dialogue and questions, and to foster opportunities for indigenous peoples and non-indigenous partners to braid TKs and western science in culturally-appropriate and tribally-led initiatives. The publication establishes firmly that in all possible cases it is tribes who should ultimately decide answers to specific questions about whether English-language words such as “traditional knowledges” are the best words to use, what knowledges should count as significant to their cultures and communities, and what the terms of sharing or declining to share should be. The information presented in these Guidelines is believed to be current as of the time of production. The Guidelines are a work in progress. The workgroup anticipates revising it over time.