New dam and reservoir to improve administration of Colorado/New Mexico La Plata River Compact

CENTENNIAL, COLO. — The Colorado Water Resources and Power Development Authority and the La Plata Water Conservancy District selected GEI Consultants, Inc., to provide dam engineering services for the Long Hollow Dam and Reservoir, which is located about 22 miles southwest of Durango, Colo. The Long Hollow Reservoir Project will assist the state of Colorado in meeting its delivery obligations under the La Plata River Compact by providing water to improve La Plata River flow delivery to New Mexico.

GEI will provide dam engineering services for the Long Hollow Dam and Reservoir project, including design of the dam, foundation, outlet works, and emergency spillway. As conceptually proposed, the 900-foot-long, 125-foot-high Long Hollow Dam will be located on Long Hollow channel, approximately one-half mile upstream from its confluence with the La Plata River. The reservoir will provide as much as 5,432 acre-feet of storage capacity and includes a 300-acre-foot reserve pool designated for release during low-flow river conditions to meet Compact requirements with New Mexico. The project will also provide supplemental water supply to existing irrigated lands within the La Plata Water Conservancy District.

This is the second Colorado State Compact project in which GEI is involved. GEI is also working with the Republican River Conservancy District for design and construction services for a pipeline to improve administration of the Republican River Compact with Nebraska and Kansas.

GEI’s project team includes Davis Engineering Service of Pagosa Springs, Colo., for hydrologic engineering, site civil surveying, and permitting support.