Water is the lifeblood of Colorado’s economy and environment. The Western Slope of Colorado is being pulled from at least two directions: water demands from the downstream states of California, Arizona and Nevada, and the thirst for water on the growing Front Range of our own state. Additionally, the Western Slope needs to plan for its own growth and expansion.
Under a compact, agreed upon in the 1920s, Colorado is obligated to deliver a certain amount of water to the downstream states every year. We have never failed to deliver that water. The water is stored or banked for use downstream in two big lakes, Lake Powell and Lake Mead. Water on the Western Slope heading in the direction of the Pacific Ocean is used many times before it reaches its destination. With each use, a portion of that water is consumed. That is the “consumptive use.” The balance of the water goes back into the streams and rivers, or it goes back into the ground and recharges the underground aquifer to be recaptured and used again downstream.
When water is transferred over the Continental Divide from the Western Slope, the western side of Colorado loses 100 percent of the consumptive use. This is called transmountain diversion, but it is actually more than that. It is a transcontinental diversion of water, where the water is moved to a completely new water drainage headed for another ocean. Hundreds of thousands of acre feet of Western water are transferred to the Rio Grande drainage annually through the San Juan Chama diversion project in Southwest Colorado. Additionally, close to 500,000-acre feet of water are transferred over the Continental Divide to the Arkansas and South Platte drainages on the Eastern Slope of Colorado. It is reported that an additional 167,000-acre feet of Western Slope water has been purchased for future needs on the Front Range.
To complicate the issue of transcontinental diversions, the water that is diverted is the freshest and cleanest high mountain water. Because this water is taken out of the Colorado River Basin and is not available for dilution, it causes an increase in the amount of salt in the water that goes west, requiring desalination projects of different kinds.
As you can see, we are running out of Colorado River Basin water for trans-continental diversions, so it is very important that we look for other sources of water to satisfy the Front Range thirst. That is why Sens. Jerry Sonnenberg and Ellen Roberts and I are proposing a South Platte River drainage water storage study in House Bill 1167. The South Platte is the one river in Colorado where excess water, in the amount of hundreds of acre feet per year, is leaving the state but could be legally contained and used here. This study will complement Gov. John Hickenlooper’s State Water Plan and the plans of the water roundtables around the state. HB 1167 was passed out of the House Agriculture Committee on a 10-2 vote and is now assigned to the House Appropriations Committee.
J. Paul Brown represents House District 59 in Colorado’s General Assembly. The district encompasses San Juan, Archuleta and La Plata counties and parts of Montezuma County. Call Rep. Brown at (303) 866-2914 or email him at jpaul.brown.house@state.co.us.
