Frequent dry spells have motivated McPhee Reservoir managers to create a draft drought contingency plan, and they have extended the public comment period.
Since 2000, drought conditions left the reservoir unfilled three times, causing water shortages for farmers and hurting the native fishery and whitewater boating on the Dolores river below the dam.
McPhee irrigators and the Colorado Parks and Wildlife fish pool received 25 to 30 percent of their full allocation in 2002 and 2013, and 50 percent allocation in 2003. The loss in farm income hurt the local economy, but improved efficiencies could have lessened the blow.
“The draft plan is an evaluation of mitigation and response actions to reduce water shortages and provide greater drought resiliency,” said Ken Curtis, chief engineer with the Dolores Water Conservancy District, during a meeting Wednesday in Cortez.
Water managers admit they have been addressing drought management “on the fly” and need a more comprehensive, long-range approach.
The report notes that the region’s arid climate depends on unpredictable mountain snowpack to fill local reservoirs.
Based on hydrologic data of the Dolores River that feeds McPhee, runoff yields have varied from 80,000 acre-feet to more than 600,000 acre-feet over the past 50 years. Seemingly fickle runoff conditions can change overnight. For example, in 2015, managers expected a 40 percent supply in early spring, but the “Miracle May” dumped record amounts of rain and snow and filled the reservoir. Since 2000, there have only been five years where precipitation in the Dolores Basin was above-average.
“Given the weather pattern in the past 16 years, the next drought and shortage could be next year,” the report states.
A key goal of the drought plan is to focus on measures that increase carryover storage of water in McPhee Reservoir from one year to the next.
“If McPhee goes into winter with good carryover storage, even a modest snowpack will be enough to fill the reservoir and meet all water obligations,” said Mike Preston, general manager for the Dolores Water Conservancy District. “We are undertaking the drought plan to be proactive, well-organized and resilient when drought shortages occur.”
Ideas in the plan are wide-ranging. Larger concepts include replacing open canals with pipelines to prevent evaporation, and building a reservoir at Plateau Creek to store water for the downstream fishery.
Other ideas include using more efficient center-pivot sprinklers and nozzles, improving coordination of water supply and delivery facilities, installing soil-moisture monitors to prevent overwatering, and leasing water among irrigators during shortages. The proposal also includes improving communication among water users during drought.
Water managers emphasized that the drought plan is an evaluation of mitigation options and is not a decision-making document. It could open the door for grants to fund water efficiency improvements.
The plan was done with a Bureau of Reclamation WaterSMART grant in partnership with the Dolores Water Conservancy District, Montezuma Valley Irrigation Co., Ute Mountain Farm and Ranch, the Bureau of Reclamation and Division of Water Resources.
Comments are due no later than close of business on July 21. Water boards and officials will review the plan and address public comments and have until Nov. 17 to submit the plan to the Bureau of Reclamation.