Gunnison Basin Water: No Panacea for the Front Range

Home Browse Search

The Gunnison: A Basin In Balance The Gunnison River no longer flows unimpeded through the valley. A num- ber of major structures built by the United States Bureau of Reclamation (Bureau)- the facilities of the Uncompahgre Project and the Colorado River Storage ProjecYs Aspinall Unit-hold and divert water along its course. Hundreds of smaller storage, diversion and conveyance structures also are found on the Upper Basin's tributaries.s In the basin as a whole, these facilities enable an annual consumption (including human use and evaporation) of 475,000 AF:' This consumption equals almost 25% of what would be the River's "natural flow" of 2,378,000 AF. A. The principal water facilities in the Upper Basin and their water rights. Like all rivers in Colorado (and most western states), Gunnison Basin water use is governed by a system of prior appropriation, also called "first in time, first in right." In times of water shortage, water rights are satisfied in a ranking based on the date of their first use ("appropriation"), often referred to as the priority date. Older, "senior" rights are satisfied ahead of more recent, "junior" rights. Applicants for water rights may obtain a conditional water right that will "date back" to when efforts were first made to put the water to use. Conditional rights holders, however, must show continuing efforts-what courts call "due diligence"-to develop these rights in a water court proceeding every six years. e Through a court decree, a conditional right can mature into an absolute water right after the water is actually used. Water rights must be applied toward a"beneficial use," defined by statute to include irrigation, hydropower, municipal use, protection of instream flows, and many other uses. Water rights are measured either as a volume, measured in acre-feet (AF), or as a rate of flow, measured in cubic feet per second (cfs). In the Gunnison basin, as elsewhere, there is a complex web of water rights that govern how water is allocated and dictate how much water might be available for new uses, either inside or outside of the Basin. In order to understand the current water uses, we examine the basin's principal projects and their associated water rights. 1. Uncompahgre Project The Uncompahgre Project, the first major federal reclamation project con- structed under the Reclamation Act of 1902,9 is designed to impound water arising in the Upper Gunnison and deliver it to farmers and ranchers in the Uncompahgre Valley. In an average year, the project diverts between 325,000 and 365,000 AF immediately below Crystal dam, roughly 27-300/o of the annual volume of water exit- ing the Upper Basin. The project consists of two major facilities: the Gunnison Diversion Dam and 5.8 mile-long Gunnison Tunnel and Taylor Park Dam and Reservoir, all owned by the United States but operated by the Uncompahgre Valley Water Users Association (UVWUA).I° • 2 • The Land and Water Fund of the R«kies