Colorado River supply, demand spells shortfall, study says
Ryan Summerlin December 18, 2012
The long-term imbalance in supply and demand for Colorado River water is projected to be roughly 3.2 million acre feet by 2060, according to a recently released three-year study analyzing over-allocation of the Colorado River.
“The Colorado River Basin Water Supply and Demand Study” underscores the need for basin states and the federal government to explore ways to conserve, manage and create water to meet shortages estimated to affect as many as 76.5 million people by 2060.
Representatives from seven Colorado River basin states and the U.S. Bureau of Reclamation took part in the joint project, which “did not result in a decision as to how future imbalances should or will be addressed,” the executive summary of the study states, “but provides a common technical foundation that frames the range of potential imbalances that may be faced in the future and the range of solutions.”
“We’ve already been addressing these issues on a Colorado-wide scale,” said Ted Kowalski of the Colorado Water Conservation Board, in statements responding to the study’s release. “Now, with this basin-wide, cooperative effort, we can get a glimpse of the bigger picture and begin to work toward planning for the future, with a well-informed idea of where we’re headed.”
But there is no “silver bullet” solution, said Colorado Water Conservation Board Director Jennifer Gimbel, in the same press release.
Laying down the law
Apportioned water in the Colorado River system exceeds the long-term historical natural flow of about 16.4 million acre feet, and demand for consumptive use is projected to range between 18.1 and 20.4 million acre-feet in 50 years.
Projected increases in demand coupled with projections of reduced supply due to climate change created the backdrop of the study. Droughts lasting five or more years may occur 50 percent of the time over the next 50 years. Meanwhile, population in the study area is expected to increase.
A study team reviewed about 150 options for dealing with these imbalances, ranging from very costly options and the technically unfeasible to the viable and barely yielding.
Desalination, watershed management, reuse, rainwater harvesting, importation of water from other locations (for example via icebergs and waterbags), ag water conservation, evaporation control, modified reservoir operations, transfers, exchanges and banking are among a varied list of proposed ideas. The general public as well as experts submitted ideas during a general request for options between November 2011 and February 2012.
Not all options are equally feasible or reliable in the long-term. Excluding the options that rate low in technical feasibility and reliability, the potential yield in considering all other options is about 3.7 million acre feet by 2035 and 7 million acre feet by 2060. “No single option will be sufficient to resolve future projected supply and demand imbalances,” reads the executive summary.
Yet doing nothing means gross water shortages.
“Without action, it will become increasingly difficult for the system to meet Basin resource needs over the next 50 years,” the study states.
And the lower basin states are the most vulnerable to shortages.
“We are surviving the imbalances by drawing down storage in Lake Powell and Lake Mead,” said Colorado’s Colorado River District General Manager Eric Kuhn, in statements responding to the study’s release. “The situation is complicated by the reality that the lower basin is using more than its share of the river, relying on surpluses and water that flows from the upper basin’s undeveloped share of the river.”
The study points to the fact the upper basin is not fully using its compact entitlement and predicts that more water development will occur in the upper basin.
But, according to Kuhn, the study also points to serious problems for the upper basin. Under the climate change scenario depicted, without additional action, the upper basin may experience a future deficit of its compact obligation as often as one in five years by 2040.
“The upper basin is currently unprepared for this possibility,” Kuhn said in statements. “To address an uncertain future, upper basin users will need to develop new risk-management strategies, including improved aggressive conservation, optimal use of storage and water-banking.”
Kuhn further cautions upper basin planners: “The reality may be that new development simply threatens existing water supplies, or that new development may only be available during increasingly rare wet cycles.”
In a press release about the study issued from the Front Range Water Council, whose chair is Denver Water’s CEO/Manager Jim Lochhead, any immediacy needed for upper basin solutions is downplayed.
Colorado’s utilities stress that “time is on our side to approach solutions thoughtfully,” and that there is no need for drastic measures.
“We don’t need to pursue drastic solutions in the short-term. Instead, we believe the best approach is to work together as a community of seven states that share the vital resource of the Colorado River to discuss the right mix of measures to meet the challenges as they arise.”
Trout Unlimited called the study a “wake-up call” in its response, and like other organizations, promoted the need for cooperation and partnerships in moving forward.
Trout Unlimited cautioned against drastic measures to meet future demand on the backs of rural areas in the West that supply a $250 billion a year business in outdoor recreation.
“The Bureau study should not be seen as a green light for unrealistic, expensive and environmentally destructive projects that move water out of their basins of origin,” said Trout Unlimited’s Dave Glenn, who grew up near the Green River in Utah. “TU and other groups have highlighted a range of cheap, pragmatic options – including conservation, reuse and water sharing – that will meet water needs without sacrificing our rivers and outdoor heritage.”