Feb 5, 2025
Colorado River Basin-Wide Negotiations for the New 2026 Operational Guidelines
The Colorado River watershed and water distribution system (Figure 1) is one of the largest in the U.S. The main channel of the Colorado River extends over 1,450 miles, covers 244,000 square miles in the drainage basin, and has the greatest elevation fall of any watershed in North America. The Colorado River supports more than 40M people, nearly 6M acres of cropland, 30 native American tribes, and provides large amounts of electrical power generation for the southwestern U.S.
Figure 1. The Colorado River watershed. Source: USGS.
The average annual flow in the Colorado River between 1906-2017 was 14.8 million acre-feet (MAF), Figure 2. The allocated water for diversion on the Colorado River has been 16.5 MAF (15 MAF in the U.S. + 1.5 MAF to Mexico). Thus, there has been a structural deficit of at least 2.0 MAF for many years. Between 2000 and 2018, the average annual flow has been ~ 12.4 MAF, which has further compounded the problem creating an overall deficit of ~ 4.0 MAF.
Figure 2. Colorado River Annual Flow, 1905-2010 with an overall average and
10-year average. Source: Bureau of Reclamation.
The foundation to the governance of the Colorado River is commonly referenced to the “Law of the River”, which is based on the Colorado River Compact of 1922 (CRC of 1922) and a collection of laws, contracts, agreements, definitions, and precedents from previous legal cases. Thus, the Law of the River is not one distinct entity but rather an amalgam of various components. A key foundational component is the CRC of 1922 which was formally negotiated among the basin states to define how much water from the Colorado River can be used by each state on an annual basis. Other agreements contribute to the aggregate Law of the River, including a 1944 Treaty, that agreed to send Colorado River water allocations to Mexico.
The CRC of 1922 was developed following a period of relatively high annual flows. Based on the records associated with the transactions leading to the signing of the CRC of 1922, the hydrologists and other scientists were providing data and interpretations to the commission that significantly influenced the CRC of 1922.
The CRC of 1922 established the operational base of Colorado River water allocation providing 15 MAF allocated among the seven basin states. Even though annual flow in the river has been less than that in most years, river managers have been able to make it work for 100 years. However, due to the annual average flow of the past 20 years being ~ 12.4 MAF, the allocation of Colorado River water based on the original CRC of 1922 has not been sustainable (Figure 2).
The Colorado River Basin is managed in a complex and multi-level legal structure that involves many stakeholders. The Colorado River watershed is divided into the Upper and Lower Basins. The Upper Basin includes the states of Wyoming, Colorado, Utah and New Mexico. The Lower Basin includes Arizona, California and Nevada. A binational treaty governs the releases to Mexico from both the Upper Basin and Lower Basin (1944 Water Treaty and Minute 319).
Due to the impacts of the recent drought, the basin states negotiated interim guidelines to deal with Colorado River water shortages and determined the reductions for each state depending on the elevation of water in Lake Mead in 2007. The reductions associated with a shortage of Colorado River water were further augmented in 2019 by the Drought Contingency Plan (DCP) among the basin states, with specific guidelines for both the upper and lower-basin states.
Within the overall structure of the Law of the River, the basin states and the Boulder Canyon Project Act water contractors must work collectively to address their water supply issues. In the Lower Basin, water supplies are administered by a federal water master, designated as the Secretary of the Interior working through the Bureau of Reclamation. In the Upper Basin, the Upper Colorado River Commission administers compliance with the 1922 Colorado River Compact. In addition, every basin also has its own unique set of laws governing the water rights that apply within those states.
The 2007 Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for both Lake Powell and Lake Mead are set to expire in 2026. The seven Colorado River Basin states and stakeholders must work together to develop the new criteria that will replace those guidelines. At present, there is a gridlock in those negotiations between the Upper and Lower Basin states and it must be resolved in 2025 to replace those guidelines expiring in 2026.
