Playfair Irrigation

Project Narrative

The Lemhi Soil and Water Conservation District (LSWCD) worked with a private landowner, the Upper Salmon Basin Watershed Program (USBWP), and the Natural Resources Conservation Service (NRCS) to design and build an irrigation system which allowed for an exchange of a water diversion from an unscreened headgate on Little Sawmill Creek to a screened irrigation diversion on the Lemhi River (L-43B). Inlet and outlet structures, a flow meter, and under- and aboveground irrigation pipe from the screened diversion were installed to provide water for irrigation. By changing the Point of Diversion to the Lemhi River (a larger water body), Little Sawmill now retains 0.14 cfs of the irrigation water that was previously withdrawn, for 0.15 mile. This also allowed for the wooden headgate, a full fish passage barrier when in use, on Little Sawmill Creek to be abandoned, therefore eliminating a barrier and opening up 0.80 mile to rearing habitat in cold clean spring water. Little Sawmill Creek was fenced on both sides (0.13 mile each side, 0.5 acre), from the upstream ford to the mouth of the creek where it enters the Lemhi River, eliminating 1 road crossing on the creek. The remaining ford had to be left in place until the Little Sawmill Crossing Project can be restarted. The remaining 60 feet of the creek will then be fenced off as well, and a second road crossing eliminated. Riparian plantings (50 trees and shrubs) were done in areas along the creek that did not have riparian vegetation (0.3 acres; 0.50 mile), concentrating on the closed road crossing. The project benefits to Chinook salmon and steelhead include improving fish passage into high quality juvenile rearing habitat in Indian Springs by removing barriers, increasing flows, reducing sediment, and improving the riparian habitat.