Colorado River Basin Climate and Hydrology State of the Science

University of Colorado, Boulder | April 15th, 2020

The Colorado River Basin currently faces unprecedented stresses. Persistent dry conditions since 2000, along with the increasing recognition that warming temperatures are

The Colorado River Basin currently faces unprecedented stresses. Persistent dry conditions since 2000, along with the increasing recognition that warming temperatures are impacting the hydrology of the basin, have led to great concerns about the long-term reliability of basin water supplies. With ever-higher stakes for water resource planning and decision making, an even greater emphasis is placed on the tools that support those activities, notably Reclamation’s operations and planning models and similar models used at other agencies. The usefulness of these system models depends on many types of datasets and forecasts that serve as inputs to them, as well as the research and scientific understanding underpinning this complex chain of data and models. The development and refinement of the different links of the chain necessarily involves researchers, forecasters, and water managers. New research efforts have advanced our understanding of the hydroclimate of the basin and how key hydroclimate processes, variability, and changes can be captured in data and models. This rapid expansion of the scientific knowledge base, and the increasing complexity of the data and models used to operationalize that knowledge, parallel the growing uncertainties about the future climate and hydrology. Accordingly, basin stakeholders have recognized the importance of reassessing the scientific and technical basis for management and planning.

Colorado River Drought Contingency Plan Authorization

United States Congress | April 16th, 2019

Authorized Drought Contingency Plans (DCPs) for the Upper and Lower Colorado River Basins, which required reduced Lower Basin deliveries beyond previous curtailment plans

Authorized Drought Contingency Plans (DCPs) for the Upper and Lower Colorado River Basins, which required reduced Lower Basin deliveries beyond previous curtailment plans at specified Lake Mead storage levels, committed Reclamation to additional water conservation efforts, and put in place plans to coordinate Upper Basin operations to enhance Lake Powell storage levels and prevent the loss of hydropower generation.

Colorado River Shortage FAQs

Arizona Department of Water Resources (ADWR) | August 1st, 2022

Comments on and Protest of Temporary Urgency Change Petition Regarding Delta Water Quality

California State Water Resources Control Board (SWRCB) | February 17th, 2023

Committee for Delta Resources Improvement Working Paper Regarding the Sacramento-San Joaquin Delta/San Francisco Bay Estuary

Committee for Delta Resources Improvement | December 1st, 1986

Compliance with D-1641 San Joaquin River October Flow Requirements

California State Water Resources Control Board (SWRCB) | October 9th, 2023

Confirmation of Initial Incidental Take for Adult Delta Smelt for the 2018 Water Year

U.S. Fish and Wildlife Service (FWS) | January 4th, 2018

Coordinated Long-Term Operation of the Central Valley Project and State Water Project, Final Environmental Impact Statement

U.S. Bureau of Reclamation (USBR) | November 30th, 2015

Critical Assessment of the Delta Smelt Population in the San Francisco Estuary, California

University of California, Davis (UC Davis) | July 1st, 2005

CVFPP Conservation Strategy Appendix C. Description of Construction Activities for Structural Modifications

California Department of Water Resources (DWR) | July 14th, 2016

This appendix [to the CVFPP Conservation Strategy] provides a general description of construction activities, focused on levee construction. It is based on the Program En

This appendix [to the CVFPP Conservation Strategy] provides a general description of construction activities, focused on levee construction. It is based on the Program Environmental Impact Report (PEIR) for the 2012 Central Valley Flood Protection Plan (CVFPP) (California Department of Water Resources [DWR] 2012).