Colorado River Basin Climate and Hydrology: State of the Science

Navigating a river of knowledge

In recent decades, increasing water demand, dry conditions, and warming temperatures have impacted the Colorado River, creating greater uncertainty about the future of the basin’s water supply. With support and guidance from over a dozen federal, state, and local water agencies, WWA researchers teamed up with leading experts to integrate nearly 800 peer-reviewed studies, agency reports, and other sources to assess the state of the science and technical practice relevant to water resources in the Colorado River Basin.

Colorado River Basin Climate and Hydrology: State of the Science aims to create a shared understanding of the physical setting and the latest data, tools, and research underpinning the management of Colorado River water resources. In identifying both challenges and opportunities, the report will guide water resource managers and researchers in efforts to improve the short-term and mid-term forecasts and long-term projections for the basin's water system.

Recent Webinar

On June 18, 2020 Western Water Assessment's Jeff Lukas and Liz Payton discussed an overview of the recently released report, "Colorado River Basin Climate and Hydrology: State of the Science," followed by Q&A.


Editors and Lead Authors:

Jeff Lukas (WWA) and Elizabeth Payton (WWA)

Click to enlarge

Quotes about the report

“Not only does this report analyze in extraordinary detail the latest data, discoveries, and decision support tools that are used in the basin, but it also lists a series of opportunities for using science and technology to help improve our understanding of current and future hydrologic conditions.”
- Colby Pellegrino, Director of Water Resources, Southern Nevada Water Authority

"This is by far the most comprehensive scientific report ever produced about the Southwest’s iconic river. Scientists summarize what they think about the past, present and future of the river and also provide challenges and opportunities for improving science to assist decision making in the 21st century."
- Brad Udall, Senior Water and Climate Research Scientist, Colorado Water Center, Colorado State University

"In connecting the dots between data, methods, models, and projections of future conditions, the State of the Science Report identifies both challenges and opportunities for strategic integration of new research and operational decision-making. It will provide an invaluable foundation for future research, planning and management in the Basin. The relationships between scientists, stakeholders, and Federal agencies that made this Report possible are critical to Reclamation’s ongoing commitment to using sound science in its management of the Colorado River."
- Terry Fulp, Regional Director, Interior Region 8: Lower Colorado Basin, Bureau of Reclamation

Download the Report

Two-page overview

Executive Summary

Full report (Recommended; 80 mb PDF with high-resolution figures)

Full report (18 mb PDF with low-resolution figures)

By Chapter:

Chapter 1 - Introduction

Chapter 2 - Current Understanding of Colorado River Basin Climate and Hydrology

Chapter 3 - Primary Planning Tools

Chapter 4 - Observations—Weather and Climate

Chapter 5 - Observations—Hydrology

Chapter 6 - Hydrologic Models

Chapter 7 - Weather and Climate Forecasting

Chapter 8 - Streamflow Forecasting

Chapter 9 - Historical Hydrology

Chapter 10 - Paleohydrology

Chapter 11 - Climate Change-Informed Hydrology