watervulnerability

Sawtooth National Forest Watershed Vulnerability Assessment, Intermountain Region (R4)
Summer Water Temperatures (Maximum weekly maximum temperature)
The temperature model predicts that summer maximum weekly maximum water temperatures will see a
steady increase over the next 70 years (0.9 o C in 2033, 1.1 o C in 2040, 1.7 o C in 2058, and 2.5 o C in 2080)
on the Sawtooth NRA. As a result, bull trout habitat within the 15 o C optimal temperature range will see a
steady decrease. The stream temperature model currently projects that 102 miles of bull trout habitat
within optimal temperatures exist across the Sawtooth NRA. Suitable habitat will see a slight decrease to
100 miles by 2040, but a substantial decrease (35%) to 66.7 miles by 2080 (Figures 12 and 13).
Figure 12. Available thermal bull trout habitat in
Valley Creek on the Sawtooth NRA in 2008.
Streams with optimal temperatures are portrayed in
purple and those outside optimal range in red.
172 Assessing the Vulnerability of Watersheds to Climate Change
Figure 13. Available thermal bull trout habitat in
Valley Creek on the Sawtooth NRA in 2080.
Streams with optimal temperatures are portrayed in
purple and those outside optimal range in red.