| Buckhorn Geotech Engineering Report |
Mancos Water Conservancy District
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| The Mancos Water Conservancy District is asking for your support of the Jackson Gulch Rehabilitation Act of 2009. The Bureau of Reclamation was formed in 1905 to build safe water storage and delivery systems in the vast and mostly rural West, enabling previously unfarmed land to develop into one of the world’s largest producers of crops. The water projects have been operated and maintained by the local water districts either directly, financially, or both. Unfortunately, due to their age, a large number of these projects are in need of major structural overhauls. The necessary work, whether it be rehabilitation or replacement, will require large capital outlays which most local, rural districts cannot afford, due simply to the small but dependent population base. As a tributary to the Colorado River system, funding for the Jackson Gulch Rehabilitation Project will help secure water not only for the residents and agricultural families of the Mancos Valley, but also to other users downstream throughout the West. Also consider that today these water projects are more than just an irrigation supply; In addition to providing water to arid lands, they have become integral to sustaining new ecosystems and habitats critical to the survival of aquatic and terrestrial wildlife. The environmental ecosystems created by water projects have provided habitat for many species including some on the endangered list. With today’s climate change there may be no greater necessity than for these projects. The health of the Mancos River Corridor and subsequent downstream river corridors is highly dependent on Jackson Gulch Reservoir. The Mancos Water Conservancy District is leveraging as much financial support as possible to implement the necessary rehabilitation work. However, we simply cannot go it alone. Federal support for this project is as necessary now as it was in 1941 when the Bureau of Reclamation acted on its vision of supplying water to areas of the rural West. Your support will further protect and promote our forefather’s vision for the vast western lands and continue to supply the needed water storage for sustaining the communities that depend upon it today and tomorrow. We thank you for your attention to this very important matter. |
| Chances of ZEBRA MUSSELS colonization in Jackson Gulch Reservoir are very low. Coal outcrops contribute CO2 to the lake, and CO2 concentrations are fatal for Dreissena. Given the adaptive nature of the quagga mussels, the growth and expansion of Dreissena needs to be monitored for many years before any lake or water body can be declared invulnerable to colonization. Environmental conditions that they can tolerate should be studied further. The potential is low for establishment of Dreissena at Jackson Gulch Reservoir. The geology of the reservoir basin includes coal seams in the Dakota Formation. Coal contributes dissolved CO2 to the water, and high CO2 concentrations are fatal for Dreissena and interfere with development of their shells. Compared with lakes across the U.S. with zebra and quagga mussels, Jackson Gulch has much different water quality with lower CalSat Potential, low pH values, and high CO2 concentrations. The conditions are Jackson Gulch, therefore, are unsuitable for zebra and quagga mussel colonization. However, given the ability of these mussels to adapt to their environment, the growth and expansion of Dreissena needs to be monitored, and water-quality conditions where they survive must be documented. More research needs to be done on the potential for Dreissena to be transported downstream from lakes to rivers and canals. |