This article is an excerpt from the Rio Grande Basin Plan Executive Summary and serves as the culmination of many hours work from the Rio Grande Basin Roundtable members and many Upper Rio Grande Basin citizens, Non-government Organizations and Agencies.
Part One:
The Rio Grande Basin Implementation Plan (the Plan) was developed in response to Governor John Hickenlooper’s 2013 Executive Order, which launched a Colorado-wide initiative to develop strategies to address the State’s growing water demands. The Rio Grande Basin Roundtable (BRT) is one of nine basin roundtables established by the “Colorado Water for the 21st Century Act.”
The Colorado Water Conservation Board provided guidance to basin roundtables, stating that “the purpose of the Basin Implementation Plans is for each basin roundtable to identify projects and methods to meet basin-specific municipal, industrial, agricultural, environmental, and recreational needs. The Basin Implementation Plans will inform and help drive Colorado’s Water Plan.”
The Plan identifies the critical water issues facing all who live, work, and recreate in the Rio Grande Basin (the Basin) and proposes ways in which those issues can be addressed, thereby advancing the statewide mission to ensure:
- A productive economy that supports vibrant and sustainable cities, viable and productive agriculture, and a robust and diverse recreation and tourism industry
- Efficient and effective water infrastructure promoting smart land use
- A strong environment that includes healthy watersheds, rivers and streams, and wildlife
The Rio Grande Basin has a diverse culture and rich history, which has been shaped by its water resources and shortages. As the community faces complex challenges and an increasingly scarce water supply, managing the use of this essential resource will be key to the future. The Basin’s water-related challenges are formidable, including:
- Sustained and systemic drought
- Significant decline of the groundwater aquifers that sustain agriculture, towns, and critical ecosystems
- Landscape-scale wildfires
- Forest succession due to diseases and insect outbreaks
- Climate change
- Dust on snow
- Lack of a diverse economy
- Degraded and at-risk wildlife habitats
- Aquatic-dependent wildlife being considered for or listed as a threatened or endangered species under the Endangered Species Act (ESA)
- Rio Grande Compact obligations to downstream states
- Costly and time-consuming permitting of water projects
- Aging irrigation and municipal water infrastructure
Working within these challenges will require cooperation of the entire community. As part of the Plan development process, the BRT appointed a Steering Committee and five subcommittees — Agricultural, Environmental and Recreational, Municipal and Industrial, Water Administration, and Public Outreach — to reach out and give a voice to the various interests in the Basin, and to carefully weigh all perspectives as the Plan was developed. Through an extensive education and outreach campaign, the BRT engaged the entire community to promote understanding of and receive feedback on the Plan’s objectives.
This Executive Summary provides an overview of the major components of the Plan, including Basin water needs, opportunities, and projects and methods that the BRT will support and implement to meet the water resources challenges ahead. The Plan itself provides a discussion of these components and is supported by technical appendices that provide in-depth detail on all aspects of the Plan.
BASIN OVERVIEW
The upper Rio Grande drainage in south central Colorado encompasses roughly 7.5% of the State’s land (approximately 8,000 square miles). Its borders are defined by the Colorado– New Mexico state line on the south, the La Garita range on the north, the San Juan Mountains and Continental Divide on the west, and the Sangre de Cristo and the Culebra mountains on the east.
Snowmelt runoff and, to a lesser extent, summer storms are the main contributors of water supply to the headwaters rivers and streams that flow from the mountains to the broad San Luis Valley (the Valley). With an average elevation of 7,500 feet, the floor of this high mountain valley receives an average of less than eight inches of precipitation per year.
The Rio Grande Compact (the Compact), signed in 1938, requires that a portion of the annual flow in the Rio Grande and Conejos River be delivered to the downstream states of New Mexico and Texas. The amount of water that legally must be conveyed annually is determined using a sliding scale, with increasing delivery requirements as the total flow increases. The Compact impacts Colorado’s water users by reducing the water available for consumptive use in the Basin.
In addition to diversions from rivers and streams, water users draw upon two stacked aquifers, known as the “confined” and “unconfined” aquifers. The uppermost aquifer, the unconfined, ranges in thickness from 30 to 100 feet and is recharged by precipitation, streams, canal leakage, and return flows from irrigation. The larger, deeper confined aquifer is separated from the upper aquifer by a series of blue clay and basalt layers, and extends in some locations several thousand feet below the surface.