3.2. Reference Reach Delineation
For both reference reaches, imagery for 2009 (pre-valley plug) was collected in August when flows were at 8.07 cms, and imagery for 2015 was collected in July when flows were at 0.26 cms. The slope of our Spring Canyon reach was .0015 (Table 1). The valley bottom measured 2.26 km2, of which ~5% (112,676 m2) was inundated by free-flowing river in 2009. The river rerouted and cut off an >800 m stretch of river between 2010 and 2012, and in 2015 ~3% (85,199 m2) of the valley bottom was inundated. We found that the valley plug contained 3% more inundated habitat as compared to the Spring Canyon reference reach in 2009, and had ~1,577% more inundated habitat in 2015 (Figures 3A and 3B). The valley plug also contained ~0.67 km2 more riparian habitat as compared to the Spring Canyon reference reach in 2009, and 0.7 km2 more riparian habitat in 2015 (Figures 4A and 4B).
We found that the Moonshine Wash reference reach had a slope of .0016 (Table 1), with ~75,227 m2 of inundated habitat in 2009, occupying ~6% (75,227 m2) of its 1.13 km2 valley bottom. In 2015, inundation was reduced to ~5% (60,556 m2) of the valley bottom. The valley plug contained 54% more inundated habitat as compared to the Moonshine Wash reference reach in 2009, and ~2,259% more inundated habitat in 2015 (Figures 3A and 3C). We observed an increase in the number of geomorphic units found in the Moonshine Wash reference reach, containing 43 riffles and 27 large woody debris structures in 2015, compared to zero in 2009. Riparian habitat did not change significantly between 2009 and 2015 in the Moonshine Wash reach, and the valley plug contained an average 0.7 km2 (Figures 4A and 4C) more riparian habitat than the Moonshine Wash reach during both 2009 and 2015.