IMA Fieldwork Collage
Environmental Projects  





Project: Fall River Trout Habitat Restoration
Location: St. Anthony, ID
Date: 2005-2006
The goals of the Fall River project were to 1) increase the available habitat for all the life stages of wild trout on a spring creek adjacent to the Fall River and 2) demonstrate whether or not habitat improvement structures in the Fall River would be successful at increasing habitat diversity given the effects from local ice damming.

The Fall River is a medium-sized, low gradient river that originates approximately 50 miles northeast of the proposed project. The adjacent spring creek is a small, low gradient spring creek that originates approximately 1 mile east of its confluence with the Fall River. Flows in the Fall River average 700 cfs, but are heavily influenced by adjacent irrigation practices. Flows in the spring creek average approximately 5 cfs. The project site lacked in-stream habitat diversity and was dominated by shallow riffles and runs. The substrates were embedded and provided limited spawning habitat. Rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) have consistently been observed in the project area in the few locations where sufficient depths provide resting areas and cover. Ice dams caused by the Chester Dam significantly affect the course of the river during winter and cause much of the main-stem flows to enter the spring creek. In order to increase the habitat diversity for trout, the project resulted in the excavation of 14 pools, the placement of 25 logs and 205 boulders in conjunction with the pools to provide cover and facilitate long-term scouring, and the construction of 11 spawning beds. This project was constructed in November 2006 and was closely monitored throughout the winter to observe to effects of local ice-damming. As of the summer of 2007, the constructed habitat components were intact and being utilized by trout.