Operating under the 2007 Interim Guidelines

The 2007 Interim Guidelines are in place from 2008 through December 31, 2025 (through preparation of the 2026 Annual Operating Plan). Reclamation’s Upper and Lower Colorado Basin Regions manage the operations of Lake Powell and Lake Mead pursuant to the Record of Decision for the 2007 Interim Guidelines. The coordinated operational diagram below outlines the coordinated reservoir operations of both reservoirs at different pool elevations. Several implementing agreements were executed concurrent to the issuance of the 2007 ROD, related to forbearance and the creation and delivery of ICS by Lower Basin contractors, as well as subsequent agreements for System Efficiency ICS projects.

A graphic showing the operating elevations of Lake Powell and Lake Mead.

Lake Powell and Lake Mead Operational Diagrams from the 2007 Interim Guidelines. Click on diagram to view full size.

Development of the 2007 Interim Guidelines

Spurred by the ongoing multi-year drought, decreasing system storage, and growing demands for Colorado River water, in May 2005, the Secretary directed Reclamation to develop additional strategies for improving coordinated management of the reservoirs of the Colorado River system.

Each year, the Secretary is required to declare the Colorado River water supply availability conditions for the Lower Division states (Arizona, California, and Nevada) in terms of Normal, Surplus, or Shortage. In 2005, regulations and operations criteria had been developed for Normal and Surplus conditions, but detailed guidelines for a water supply shortage had not been established. It was anticipated that, among other elements, these additional strategies would identify those circumstances under which the Secretary would reduce annual water deliveries from Lake Mead such that use of mainstream water by the Lower Division states is below the 7.5 million acre-feet apportionment (a "Shortage") pursuant to Article II of the Decree in Arizona v. California.

In response to the Secretary's direction, Reclamation initiated a National Environmental Policy Act process and preparation of an Environmental Impact Statement to develop and adopt interim operational guidelines to address the operations of Lake Powell and Lake Mead during drought and low reservoir conditions. The proposed Federal Action included four key elements:

  • Shortage strategy for Lake Mead and the Lower Division states
  • Coordinated operation of Lakes Powell and Mead
  • Mechanism for the storage and delivery of system and non-system water in Lake Mead
  • Proposed modification/extension of the existing Interim Surplus Guidelines

Five federal agencies participated in the EIS process as Cooperating Agencies: the Bureau of Indian Affairs, the National Park Service, the U.S. Fish and Wildlife Service, the Western Area Power Administration, and the U.S. Section of the International Boundary and Water Commission. The Cooperating Agencies met regularly with Reclamation, assisted with the development and evaluation of alternatives, and assisted in the preparation of the EIS. Reclamation also coordinated the development of the EIS with the seven Basin States, Indian Tribal Governments, Mexico, other key stakeholders and interested parties, and the public. Meetings with these various groups occurred throughout the process in addition to the multiple public scoping meetings held throughout the Basin.

A Draft EIS was released at the end of February 2007 and a Final EIS was published in November 2007. The outcome of the NEPA process was the 2007 Interim Guidelines. On Dec 13, 2007 the Secretary of the Interior signed the historic decision that implements innovative strategies for Colorado River management, charting a water management course for the future.

ROD & EIS Documents

Last Updated: 2/9/24