Early Ideas on Dam Deconstruction

The Josh Ames Diversion and Check Structure is located on the Cache la Poudre River in Larimer County, approximately one third of a mile upstream from Shields Street in Fort Collins. It is unknown when the structure was built, but a rehabilitation of the structure occurred in 1966. The Josh Ames ditch and its diversion structure are no longer in use and thus the structure across the river is no longer needed. It also collected sediment and ash that flowed down through the Poudre River after wildfires raged through upper portions of the watershed earlier this year. The structure is composed of an abutment on each bank connected by a single vertical concrete curtain or wall spanning the river. The wall is 18 inches thick and approximately 6 feet in height. Along the north bank is a 17-foot intake tower that once served as the intake to the Josh Ames ditch.

Colorado Water Trust, in cooperation with the City of Fort Collins, has an interest in the removal of the structure. Removal of the structure would allow enhanced flow and fish passage in this reach of the river as well as improve the streambed for increased fish habitat. The structure has not been in use since the early 1970’s when the City of Fort Collins purchased the water rights from the ditch company and moved the point of diversion to the City’s upstream withdrawal point. The removal of the structure would also include regrading of a portion of the river to re-establish an advantageous slope in the river. The sediment built up behind the structure in the river would be excavated and re-distributed in the channel and on the upstream banks for stabilization. It is anticipated that the removal of the structure would occur in winter months when river flows were minimal or could potentially be diverted upstream.