Gunnison Tunnel: Engineering History of an Early American Reclamation Project: Fid-Bau Portal

Gunnison Tunnel: Engineering History of an Early American Reclamation Project

McAdams, Mallory / Wang, Judith

Abstract

This paper describes the surveying, engineering, and construction operations performed in the construction of the Gunnison Tunnel for the Gunnison River Diversion Project. The Gunnison Tunnel, which diverts water from the Gunnison River to the Uncompahgre Valley, was one of the first major engineering projects undertaken by the federal government under the authority of the U.S. Reclamation Service. It has been recognized as a national historic civil engineering landmark for the engineering feats involved in its construction, including the performance of site investigations and survey operations through extremely harsh terrain and its construction crews’ perseverance through several dramatic accidents. It is observed that a potential cause of these multiple accidents was an insufficient knowledge of the geological subsurface properties, leading to significant differences between expected and encountered subsurface conditions. This was particularly problematic with respect to the existence of cohesionless soils and water and gas seams, resulting in numerous fatalities and injuries among hard rock miners who were inexperienced with tunneling through cohesionless soils.