The DCP safeguards water supply for 40 million people who rely on the Colorado River, which is facing severe drought exacerbated by climate change.
In this Medium post we’ll explain why the DCP is critical for western states — and what comes next.
The Colorado River winds its way across 1,450 miles of the southwestern United States and Mexico. It provides water for 5.5 million acres of irrigated agriculture and to cities and towns across the West, including the residents of Los Angeles, Phoenix, Tucson, San Diego, Las Vegas, and Denver. Colorado River water makes possible those perfect peaches from Palisade, Colorado, and winter salads from southern California. Outdoor recreation along the Colorado River, including rafting, fishing, bird watching, and hiking, helps support an estimated $25 billion recreational economy. The Colorado River is an essential element of many of the nation’s most iconic landscapes, from the headwaters in Rocky Mountain National Park down through the Grand Canyon.
This river is essential to western life — and it’s at risk. For nearly two decades, the Colorado River Basin has been in drought. Water levels at key reservoirs have dropped. Scientists point to signs of long-term aridification due to climate change. Even with above-average snowfall this year, water officials warn that the long-term effects of the drought will be difficult to overcome.
Water managers in the Basin are taking action. In a state-led approach to large-scale water conservation, the states have developed a Drought Contingency Plan that was signed into law last week. Chairman Grijalva led the charge in Congress to ensure the DCP could proceed as quickly as possible. We’ll explain what the DCP does, but first, let’s walk through some history on how the Colorado River is managed.
The Colorado River is governed by a complex set of laws, court rulings, and agreements known as the Law of the River. The cornerstone of the Law of the River is the Colorado River Compact of 1922. The Compact allocates 7.5 million acre feet (maf) of water to the Upper Basin States — Colorado, New Mexico, Utah, and Wyoming — and 7.5 maf to the Lower Basin States of Arizona, California, and Nevada. The compact apportions water for 22 tribes. Mexico’s allocation of 1.5 maf was established through a separate 1944 treaty between the U.S. and Mexico, bringing the Colorado River’s total apportionments to 16.5 maf.
When the Compact was signed nearly a century ago, it was assumed that there would be ample annual flow of 16.4 maf per year. The people who made that assumption didn’t realize their data was based on measurements made during some of the wettest years in the historical record. We know now that the Colorado River’s annual flow was actually 10 percent lower than originally estimated. Since the turn of this century, flows have continued to drop down to 12.4 maf during the 19-year drought that has taken hold of the Basin. As flows have decreased, the Colorado’s two major reservoirs — Lake Mead and Lake Powell — have drawn down to historically low levels. Operations at these reservoirs are critical to water management across the entire Basin.
By 2007, drought caused Lake Powell to drop to a third of its capacity. The Department of the Interior and the seven Basin states responded by developing the 2007 Interim Guidelines, a plan for operating Lake Mead and Lake Powell in coordination to stave off dramatic drops in water levels at either reservoir. The 2007 Guidelines helped to manage water levels as a united system, but they were still unable to prevent Lake Mead, the Lower Basin’s primary reservoir, from dropping to below 40 percent of its capacity. Once the water level reaches below 1,075 ft., a “shortage” condition is triggered. If water drops below this level, Arizona and Nevada would face allotment cuts. As Lake Mead falls further, the cuts get bigger. (Under the 2007 Interim Guidelines and the Law of the River, California would not be obligated to make those same cuts.)
Despite the best efforts of water managers and users, the water levels at Lake Mead have hovered perilously close to 1,075 ft. Luckily, the seven Basin states have come together to the negotiating table to create a collection of voluntary water conservation agreements collectively known the Drought Contingency Plan.
Through the DCP, the Basin states have agreed to water conservation measures that will help keep reservoirs at stable levels. The agreements work differently in the Upper and Lower Basins, based on how the major reservoirs in each Basin — Lake Powell and Lake Mead, respectively — are managed.
The Upper Basin states have developed two strategies to ensure more water reaches Lake Powell: a short-term response and a long-term plan.
The first element of the Upper Basin’s DCP is an emergency response measure that will only take place if levels at Lake Powell get to a dangerously low point. The states determined that if Lake Powell drops below an elevation of 3,525 ft., normal hydropower production and water releases are at risk. If the reservoir reaches down to that critical elevation, the Upper Basin states and the Bureau of Reclamation will meet to develop a coordinated strategy to send down water from upstream reservoirs to increase water levels at Lake Powell.
The Upper Basin’s long-term plan is to establish a new program to reduce water use. Up to 500,000 acre-feet of water savings can now be stored at Lake Powell under the DCP. The states are still working on their plan for a “Demand Management” program that will help achieve this water conservation, but through the DCP the states now have a place to put their conserved water — an essential foundation for the new program’s success.
The Lower Basin states’ DCP commitments include new water conservation measures that will reduce the amount of water withdrawals from Lake Mead. By reducing the water they take from Lake Mead through in-state conservation measures, the Lower Basin states will avoid never-before-seen shortage conditions that would trigger more dramatic cuts. In a significant step for water conservation, California agreed to accept water cuts under the DCP, even though the state did not have to accept any cuts under prior agreements. In order to meet new commitments under the DCP, Arizona and California are each developing their own intrastate agreements to define which water users will undertake voluntary conservation measures to implement these cuts.
Mexico has also agreed to help maintain Lake Mead’s water levels. This international approach to water conservation was agreed to in concept years ago, but with the understanding that the plan would be tabled until the DCP was signed into law. With the DCP now enacted, that planning process can begin.
● Tribes in Arizona, including the Gila River Indian Community and the Colorado River Indian Tribes, have played a significant role in DCP implementation plans. Without tribal participation, the DCP would not be possible.
● All seven Colorado River Basin states support the DCP.
● Water agencies across the Basin support the DCP because it provides certainty for water deliveries over the next few years.
● Many environmental NGOs have expressed their support for the DCP plan. This support was solidified when legislative language clarified environmental protections.
● Climate experts say the DCP is an important step that will help manage climate-induced drought over the next few years by allowing for voluntary water use reductions.
The seven Colorado River Basin states developed the DCP to promote water conservation. The states have recognized for years that they’d need Congressional support to move the plan forward. Unfortunately, certain aspects of today’s Law of the River disincentivize water conservation. Thanks to Congress authorizing the plan, water conservation at the necessary scale can now proceed.
This didn’t just happen overnight. The Natural Resources Committee held a hearing on the bill to listen to the seven Basin states, and Congress acted quickly to pass the DCP once the need was clear. The clock for next year’s water conservation planning starts ticking in mid-April of this year, so Chairman Grijalva pushed the bill through an expedited process.
The Colorado River Drought Contingency Plan Authorization Act was co-sponsored by 37 bipartisan Members of Congress and 14 senators across every Basin state. With the DCP now law, water conservation can begin in earnest to protect reservoir levels on the Colorado River.
The DCP and the 2007 Interim Guidelines for water use both expire in 2026. The Plan provides an important bridge to that end date so that the Basin states can protect Lake Mead and Lake Powell in the years to come. The states will soon return to the negotiating table to establish a new set of guidelines for the Colorado River’s reservoirs. The DCP is only the first step in protecting the Colorado River’s future, but it’s a critical step.
It’s a win for bipartisanship.
It’s a win for taking action to tackle climate change.
It’s a win for state and federal agencies working as a team.
And it’s a win for the Colorado River and the tens of millions of people who depend on it.