Crystal Creek Dam Improvements Project

The purpose of this project is to rehabilitate Crystal Dam to maximize its service life. Crystal Dam is a steel faced earthfill embankment constructed in 1935 by the City of Colorado Springs on the north slope of Pikes Peak (spillway elevation 9229’ +/-). The upstream slope is 2:1. The water barrier on the dam is an upstream welded steel face (approximately 70 vertical feet), originally of 1/4" thickness. The face was originally protected with red lead and linseed oil, and top coated with aluminum paint. The steel face is connected to a concrete slab (apron) of up to 36 vertical feet height which forms the water barrier beginning approximately below the outlet elevation and continuing to a concrete cutoff wall and grout curtain at the heel of the dam. The steel face is embedded into a reinforced concrete plinth in the groins. At the top of the steel face, a concrete parapet wall serves as the water barrier and supports the fill. The Pikes Peak Highway runs over the crest of Crystal Dam and the Crystal Reservoir Gift Shop is located to the Northwest of the Dam. The spillway is located on the left abutment of the dam with a weir crest length of 55’ in a reinforced rectangular concrete channel. The outlet works for Crystal Dam consist of two 20” diameter steel pipelines in a reinforced concrete tunnel located at the base of the left abutment. The tunnel is approximately 300’ in length. The steel face has been recoated multiple ties over the life of the structure. Most recently, the entire face was abrasive blast cleaned and coated with coal tar epoxy in 1988. The upper portion (approximately the top 18 feet of elevation) was blast cleaned and recoated with a zinc rich primer and epoxy in 2003. The 1988 and 2003 coatings require removal and replacement. This project will clean, repair, prepare and re-coat the steel face with a 100% solids high-build aromatic polyurethane elastomer. The outlet works will be replaced with a single 30” HDPE outlet pipe including an upstream slide gate and isolation and control valves in the valve house downstream. The annular space between the outlet conduit and the existing tunnel will be grouted. Concrete repairs will be made to the spillway.

Division 02 -	Existing Conditions, Subsurface Investigation.
Division 31 -	Earthwork, Site Clearing, Grading, Excavation and Fill, Subgrade Preparation, Excavation, Shoring, Tunneling and Mining, Tunnel Excavation.
Division 35 -	Waterway and Marine Construction, Dam Construction and Equipment.