Innovative static self-cleaning screen protects fish and removes debris at irrigation diversions
Strong, James J., author
Weir, Robert K., author
U.S. Committee on Irrigation and Drainage, publisher
At the time many irrigation projects were conceived at the tum of the last century, and prior to 1930, little consideration had been given to providing screens for fish protection. The passage of the Endangered Species Act, plus recent environmental concerns for protection of fish as a natural resource having considerable economic value, however, has prompted the construction of new diversion structures to exclude both resident and migratory fish from entering irrigation canals where they would otherwise be lost. One such installation, on the Flathead Irrigation Project in Montana, included a stream diversion to accommodate a screening facility that had to be suitable for a remote location, since electricity was not available to operate a cleaning mechanism. An additional requirement for small irrigation diversions is the need to be very cost-effective and reliable with a minimum of maintenance. A screening system that meets these requirements has been developed utilizing concave screen panels arranged in a linear array. The screening system is installed along the crest of small dams or diversion structures. As the water flows over the screen, a portion passes through to the irrigation system and the remainder flows across the screen surface carrying aquatic life safely downstream. Components are fabricated from stainless steel and are designed for maintenance-free operation. The screening structure on Crow Creek, which is part of the Flathead Irrigation Project, was the outcome of negotiations between the Bureau of Indian Affairs and the Tribal Council of the Flathead Indian Tribe. Installation techniques and costs for the fish screening structure at the Flathead Irrigation Project are presented.
Presented at the 2000 USCID international conference, Challenges facing irrigation and drainage in the new millennium on June 20-24 in Fort Collins, Colorado.