Rio Grande Reservoir is located on the headwaters of the Rio Grande River in the San Juan Mountains in Hinsdale County, Colorado.
Landslide Complex on the Left Abutment of the Dam.
The reservoir, constructed in 1914, is impounded by an earth and rock fill dam with a maximum height of 111 feet and a length of approximately 550 feet. It contains a 15-foot wide horseshoe-shaped, unlined rock outlet tunnel in the right abutment. A 32-foot wide concrete-lined chute spillway excavated in rock is located on the right abutment. The dam was constructed on a large landslide mass on the left abutment and seepage of up to 5cfs occurs when the reservoir is full.
The purpose of the proposed rehabilitation is to allow for the reservoir to be safely operated at a higher capacity, with storage at higher stages carried over from one year to the next.
Deere & Ault Consultants, Inc. performed a preliminary design level evaluation which included:
- Detailed geologic mapping of the reservoir in order to evaluate existing landslides in the area.
- Detailed review of historical documents and records.
- Slope stability and seepage analysis of the dam, abutments, and reservoir area.
- Hydraulic calculations for new outlet facilities.
- Preparation of preliminary plans for rehabilitation of the dam and outlet.
- Preparation of construction cost estimate.
Deere & Ault Consultants, Inc. is currently engaged in the final design of the rehabilitation.
Client: San Luis Valley Irrigation District