The Colorado River Drought: A Sobering Glimpse Into the Future
In the grip of 11 years of drought in the Colorado River Basin, Lake Mead is a sobering sight with its ever-growing white bathtub ring and declining water level – about 130 feet below capacity. In October, Lake Mead reached its lowest elevation, 1,082 feet, since the 1950s. Mead’s level has since risen a few feet, but it remains at only 41 percent of capacity. Thanks to December storms and an above-average January snowpack in the Colorado Rockies, the likelihood of more water being released from Lake Powell to Lake Mead has increased and the potential of a 2012 Lower Basin shortage declaration has decreased.
But Lake Mead’s record-low watermark offers a sobering glimpse into the future, especially when considering the big picture. The last 11 years have been the driest in a century of records, and when paleoclimate tree ring records are considered, the period ranks as one of the driest in the last 1,200 years, according to the federal Bureau of Reclamation (Reclamation).
At issue is the 1922 Colorado River Compact dividing the water between the Upper and Lower basins. Each basin was basically allocated 7.5 million acre-feet annually and negotiators believed the river could provide that and more. But negotiators were dealing with a relatively wet period and it is now known that the river’s reliable supplies are less than believed. Today, even with the system’s significant storage space and continued measures to use water more efficiently, there is increasing concern that demands have already overtaken water supplies – and some say the reservoirs may never recover.
“The Colorado River system is constantly on the edge considering inflow [averages] only 15 million acre-feet,” said John Entsminger, assistant general manager of Southern Nevada Water Authority (SNWA). “Looking at the paleo records, you have to be prepared for extreme droughts – even without climate change.”
Considering the question of whether the glass is half-empty or half-full, federal officials point out that basinwide storage remains at approximately 54 percent despite a decade of drought and water deliveries to farms and cities in the seven basin states and the Republic of Mexico. Total system storage benefits, in large part, because Mead’s Upper Basin counterpart, Lake Powell, is at 58 percent of capacity.
“The reservoirs are doing what they are designed to do,” said Lorri Gray-Lee, regional director of Reclamation’s Lower Colorado Region. “Reclamation officials are switching to a ‘low reservoir management’ scheme [and] the states are working with Reclamation on how to creatively address the issue.”
The 2007 federal Record of Decision (ROD) for Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead established rules for when a shortage would be declared in the Lower Basin and criteria for management of the two reservoirs. The seven Colorado River Basin states, in turn, inked agreements designed to help meet new water demands while protecting water rights.
It will not be known until April 1 whether conditions in the Upper Basin will result in an equalization release from Powell to Mead this water year. (The water year runs from September 30 to October 1.) Under a pre-set formula in the ROD, officials predict a 76 percent chance of total releases of more than 11 million acre-feet from Powell based on forecasted April through July inflow. Under normal conditions, 8.23 million acre-feet would be released. Although it remains to be seen whether the larger equalization release will come to pass, Gray-Lee predicts the normal release will, at the least, be augmented by an approximately 750,000 acre-feet to “balance” the reservoirs in accordance with the Interim Shortage Guidelines.
Either type of release will delay when Mead reaches the first shortage trigger and push back when the first-ever shortage would be declared for the Lower Basin.
“The states have made an effort to talk with each other and try to do some extraordinary things to keep Lake Mead above the shortage level,” said David Modeer, general manager of the Central Arizona Project (CAP). “All of us are of the same mind: we want to keep water in Lake Mead.”
Today’s approximate 41-58 split between Mead and Powell is nearly the reverse of the situation in 2005 when Powell was at 33 percent capacity and Mead was 67 percent full. At that time, the Upper Basin states (Colorado, New Mexico, Utah and Wyoming) were concerned about potential water supply cutbacks in order to meet delivery requirements to the Lower Basin. They also were concerned that continued demands from the Lower Basin could lower Lake Powell below the minimum level required for hydropower generation.
Federal officials used a carrot-stick approach to push the Upper Basin and Lower Basin states (Arizona, California and Nevada) into negotiations over reservoir storage and shortage criteria for the Lower Basin – ultimately leading to the 2007 ROD.
“Without the willingness of the states and tribes to set aside differences and find common ground, we would not be in the position we are in today to tackle these issues,” Reclamation Commissioner Michael Connor told participants at the December Colorado River Water Users Association (CRWUA) conference.
The issues facing the Colorado River Basin are daunting when one considers water use, projected population growth, the needs of the environment and climate change. “We know there will be a 1 to 3 degree Celsius rise in Basin temperatures. It’s well documented,” Connor said. “We will have a longer growing season and an earlier snowmelt. Climate change may increase precipitation in the Upper Basin, but it will decrease precipitation in the Lower Basin. We are predicting a decline in runoff between 6 percent and 20 percent by 2050.”
The Lower Basin states and Reclamation have already taken steps to stretch supplies: lining the Coachella Valley Canal has conserved about 26,000 acre-feet annually, lining the All-American Canal has conserved about 67,000 acre-feet annually, and the new Warren H. Brock Reservoir (formerly known as Drop 2) in the Imperial Valley at the U.S.-Mexico border is projected to capture 70,000 acre-feet a year for use on the U.S. side of the border. Meanwhile, a trial run of the Yuma Desalting Plant already has produced 20,000 acre-feet of water, most of which was delivered to Mexico as part of its 1.5 million acre-feet allocation, allowing more water to stay in Lake Mead.
SNWA, the Metropolitan Water District of Southern California (MWD) and the CAP asked Reclamation to leave a portion of their 2010 annual allocations in Lake Mead rather than deliver it. While the quantities of water are small, the states recognize that any steps they can take to help maintain Mead’s elevation will forestall the need to declare a shortage. “It is in the states’ interest to leave water in Lake Mead because it could be the difference between a shortage declaration and no-shortage declaration,” said Pat Mulroy, general manager of SNWA.
The U.S.-Mexico agreement (Minute 318) signed in December also should help keep Mead’s elevation above 1,075 – the first shortage trigger. Under terms of the agreement, Mexico can temporarily store up to 260,000 acre-feet of its water in Lake Mead through 2013 as Mexican officials fix infrastructure damaged in the April 2010 earthquake. Officials on both sides of the border hope this agreement will lead to a long-term program of binational water development, transfers, storage and management arrangements. “Minute 318 is a remarkable achievement from a humanitarian perspective, but it also lays important groundwork for a much-needed comprehensive water agreement with Mexico on how we manage the Colorado River,” Interior Secretary Ken Salazar said in a Dec. 20 press release.
Even with the landmark 2007 agreement in place and the ongoing collaborative efforts among the states and Reclamation, tension remains over supply and demand issues in the Colorado River Basin. Upper Basin officials note that because of dry hydrology and a lack of storage, their states have routinely had to take shortages since 2001 while still meeting their Compact commitment to the Lower Basin. “[The Lower Basin] got by, in the past, due to very good hydrol-ogy and a lot of surplus water above the minimum promised under the Compact,” said Don Ostler, executive director of the Upper Colorado River Commission. “The Lower Basin states are collectively using more than the minimum firm amount promised under the Compact, but are not adjusting for evaporation and seepage losses, which are significant.” This, he said, “further contributes to the imbalance between anticipated Lake Mead inflows and demands, thereby exacerbating the non-sustainability issue as we look at declining flows in the future.”
Ostler said Upper Basin interests are encouraged by the new U.S.-Mexico agreement and strongly support the Lower Basin’s efforts to “create” more water through augmentation, conservation, banking water in Lake Mead and other programs. But concern remains over the sustainability of Lower Basin demands and the Upper Basin states’ ability to deliver water called for in the Interim Shortage Guidelines and the 1922 Compact without further impacting their ability to develop their own share of the Colorado River.
“The ROD tied the two basins together,” said Ted Kowalski, section chief of the Interstate and Federal Section of the Colorado Water Conservation Board. “Every action on the river now affects the Upper Basin and the Lower Basin.”
The new “Colorado River Basin Water Supply and Demand Study” could help provide a roadmap to the future. In 2009, Reclamation selected three river basins, including the Colorado, for its Basin Study Program. The study’s goal is “to complete a comprehensive review of water supply and current and long-term demands through 2060; to assess options for resolving water supply imbalances; and to develop recommendations for future consideration to address current and projected imbalances.”
A key part of the study includes an assessment of potential impacts of climate variability and climate change on water demand, supply and system reliability. The study will also develop and evaluate adaptation and mitigation strategies - including potential for augmenting the Basin’s water supplies. The $2 million Colorado River Basin study is funded 50 percent by the federal government and 50 percent by the seven Basin states. The states and Reclamation expect to release a full draft of Phase I of the report in February. Additional reports from the study will be released through January 2012.
This issue of Western Water examines the Colorado River drought, and the ongoing institutional and operational changes underway to maintain the system and meet the future challenges in the Colorado River Basin.
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Drought on the Colorado River, its effect on Western states and the agreements between area stakeholders to avoid the worst of the drought consequences are the subject of this issue of Western Water. In California, La Niña conditions have brought a huge amount of precipitation in a short time and the reservoirs are full. It is good fortune for California but it is not reflected in the Southwest where this condition could bring continued drought and drier than average conditions.
In California, that abundant water could become flood water - especially in the Central Valley, according to a recent study by the U.S. Geological Survey (USGS) that puts the flood risk for the Valley into perspective. California tops all other regions in the country for the risk of catastrophic storms, according to USGS. The study says one huge storm could last for nine straight days and inundate much of the Central Valley. These types of “pineapple express” warm storms don’t occur often – the last major one was in the early 1860s. As geological records going back to 212 A.D. tell us, it could happen every 150 to 400 years. The study looked at soil samples showing strong evidence that mega-storms have hit the state on at least six previous occasions in the last 2,000 years. If past truly is prologue, it will happen again.
When Europeans came to California in search of gold, they heard stories from the native people about the vast inland sea caused by annual flooding. In fact, Gen. John Fremont spent some time on the Sutter Buttes in the winter of 1846 – stuck there because the Valley became an “inland sea.” Before the dams and levees were built, boats often traveled from Sacramento up and down much of the Central Valley. And even after those structures were built, devastating floods periodically still destroyed lives and property – the most recent in memory in 1986 and 1997. And then came Katrina, and we all learned a lot about levees that fail a city.
After Katrina, the voters of California passed bonds to upgrade levees surrounding the Central Valley. A study to decide how to improve the system and keep the flood waters away from homes and farms is due to the state legislature in 2012. To assist that effort, I have been recording some of the thoughts of some long-time flood observers – lawyers and engineers – who have worked on water projects since the 1940s. All have experienced drought and flood in California and worked during their careers to protect us from the effects of both. Through those years, the flood control “system” developed in pieces – between wars, floods and drought and when money was available.
Now a new generation is looking for creative solutions – not to control, but to manage floods. It’s not going to be easy to protect people and property in the floodplains where the Valley is quickly urbanizing. Let’s hope there is the time and the public is willing to make changes and improvements to a system that has served us in the past and must meet an uncertain future.
In the News
Watermaster Report Targets Agricultural Water Use Reductions
A report by Delta Watermaster Craig Wilson calls for a renewed focus on agricultural water efficiency, urging the creation of a new entity within the State Water Resources Control Board to crack down on wasteful and unreasonable water use.
“Because the agricultural sector accounts for a large portion of the state’s developed water, efficiency improvements on a relatively small percentage of farms can result in significant water use reductions,” states the report, The Reasonable Use Doctrine & Agricultural Water Use Efficiency, released Jan. 11.
The Delta Watermaster was created as part of the 2009 legislative water package. Wilson’s report keys off the Reasonable and Beneficial Use Doctrine, which it calls “the cornerstone of California’s complex water rights laws.” The Doctrine states that the state’s water “be put to beneficial use to the fullest extent … and that the waste or unreasonable use or unreasonable method of use of water be prevented.”
The report notes that “all water use must be reasonable and beneficial regardless of the type of underlying water right,” and that “no one has an enforceable property interest in the unreasonable use of water.” Because “small changes in agricultural water use efficiency can produce significant amounts of ‘wet’ water,” the agricultural sector is suited to identify “economically justified and locally cost effective water management techniques that retain the value of return flows to both downstream users and other environmental beneficiaries.”
The report cites the inefficiency of water delivery systems, many of which cannot bring water to farms at times when it can be used most efficiently. Consequently, farmers are unable to make best use of irrigation scheduling to reduce water use. The report says an enforcement action should be commenced to address an unreasonable agricultural use of water “where such use is higher than similar uses in similar locations or circumstances,” and that a case would be identified and pursued where excessive agricultural water use is lost through evaporation or flows to a saline sink.
Conservation advocates applauded the report, saying that promoting efficiency across the board among agricultural users has been challenging and that efforts need to be made that match conservation programs in the urban sector. In a Jan. 11 post at the Natural Resource Defense Council’s blog, Switchboard, Barry Nelson wrote that farmers that are unable to schedule deliveries are at a disadvantage.
“These farmers are forced to irrigate when they can, rather than when their crops truly need it,” Nelson wrote. “It won’t surprise you that water use in these delivery systems is higher than elsewhere. In a state with limited water resources and damaged fisheries and river ecosystems, that sounds pretty unreasonable to me.”
Agricultural interests said the report fails to account for how water is used on the farm, and that converting all delivery systems to on demand would not save large volumes of water. “They forget, or maybe ignore, information from actual irrigation experts that shows that on a basin-wide level, farm water use is over 90 percent efficient,” Mike Wade, executive director of the California Farm Water Coalition said in response to Wilson’s report. “On-farm water use efficiency efforts do not automatically translate into more water in the system.”