Crack appears on Ritschard Dam crest road
January 9, 2019
KREMMLING — A crack was discovered Friday during a routine walking inspection of Ritschard Dam at Wolford Creek Reservoir, but experts say they are not concerned for the integrity of the dam.
A crack in the gravel road surface of the dam's crest road, which is only open to foot traffic, was observed near the dam's west end, according to staff at the Colorado River District, which owns and operates the dam.
The crack was initially observed to be about a half-inch to one-and-a-half inches deep and about a quarter- to a half-inch wide. After cleaning and probing the crack, it could be traced through the top layer of road base to a depth of six to seven inches, but could not be traced through the fill material below the road base.
The crack is being observed and measured by on-site personnel daily, according to the district.
Ritschard Dam impounds Wolford Mountain Reservoir on Muddy Creek about four miles north of Kremmling. It is a clay core, rock fill dam about 120 feet high. The dam crest is finished with a six-inch layer of road base gravel.
According to the Colorado River District, the dam has "a non-emergency history of greater than expected settlement and downstream deformation."
Crews last fall raised a portion of the dam's center to its original height, by adding concrete block walls and two feet of fill to the dam crest. The crack, according to district staff, is located about 225 feet west of that area.
Initial cleaning of the crack and measurements of depth and width were performed and are being repeated on a daily basis, according to district staff.
Excavation of the crack area to the top of the clay core will require digging a trench at least 20 inches deep, according to the district. Sufficient clay core surface would then be exposed to reveal any cracks that might be spreading in the core, but not reflected in the fill above the core. Though because the dam crest is currently frozen, district staff are unsure if they will be able to dig a sufficient trench.