A hierarchical strategy for prioritizing the restoration of 83 impaired tributaries of the Big Blackfoot River

Abstract

Moderate (2/3) 2002 Gallagher Creek, a 2°^o rder tributary to upper Nevada Creek, flows~7 miles through both public (National Forest) land in headwaters and private land downstream of mile~3. Low native species value, low water quality benefits, no sport fishery value to the Blackfoot River, ranks Gallagher Creek low on the restoration priority list for non-project streams. Gallagher Creek supports only resident WSCT. The lower reaches support low densities of WSCT that increase to moderate numbers in middle reaches. Fisheries impairments in lower reaches include localized livestock-induced stream bank damage and an undersized culvert.

The Big Blackfoot River restoration progress report for 2002 and 2003

“…Fisheries impairment throughout the upper Blackfoot River watershed is documented, with the majority of impairment occurring at lower elevations and primarily on private land (Pierce et al 2000;2001;2002b;Confluence 2003;this report (Dunham et al 2001). Redds of fluvial bull trout are generally large (> 3 ft long) and can be easily identified by a cleaned, oval shape (pit), and a mound of unconsolidated gravel (tailspill) left by a females digging activities (Kondolf and Wolman 1993 We counted four redds in Bull trout spawning area temperature study Bull trout spawning occurs at discrete locations, which coincide with water temperature regimes typically influenced by groundwater inputs, a source that moderates temperatures throughout the entire year.…”

“…Tributary inventories in the Blackfoot watershed have identified pervasive alterations to tributaries at the low-to mid elevations of the watershed with 85 of 90 inventoried streams identified as fisheries-impaired (Pierce et al 2002b). This level of tributary alteration contributes not only to population declines at a broad level; it also necessitates expansive tributary restoration as a primary method of native species conservation and recovery.…”

“…Implications with pool and cover associations relate to certain land management (unregulated riparian grazing and timber harvest), which potentially influence the integrity of stream banks, overhanging vegetation, and recruitment of LWD, more so in alluvial (C-type) channels, which are more subject to stream bank damage, channel widening and subsequent loss of cover than geologically controlled (B and F-type) channels (Rosgen 1996). Adverse alterations of WSCT habitat in (C-type charmels) occurs in the middle and upper reaches of the study area (Marler 1997;Confluence 2003) and is extensive in tributaries with comparable alluvial valley bottoms (Pierce et al 2002b).…”

“…As a tool to assist recovery of native fish populations, resource agencies, conservation groups and irrigators are screening irrigation diversions in order to minimize population losses due to ditch entrainment. Screening irrigation ditches in the Blackfoot River drainage had contributed to increased fish densities in tributary populations as well as the overall densities of imperiled native fish in the Blackfoot River (Pierce et al 2002b).…”

“…Restoration activities in 40 tributaries of the Blackfoot Watershed(Pierce et al 2002b, Results Part III).…”