Biological Opinions - Bureau of Reclamation

peak flow, higher spring flows through the descending limb of the hydrograph, and enhanced
flow variability and volume through the summer period (Figure 11.10).
Figure 11.10. Proposed action and observed IGD discharge and UKL elevation since NMFS 2010 Biological
Opinion was implemented. Proposed action IGD daily discharge was calculated for water years 1981-2011
based on a 7-day moving average.
The resultant changes to the 2010-2011 proposed action hydrograph described here, are in part,
due to a higher UKL elevation on March 1, 2010 and thus, a greater UKL Supply (Figure 11.10).
Based on WRIMS modeling, implementing the proposed action results in a higher UKL
elevation at the end of February 2010, as well as in most years (Figure 11.11), which in turn
results in enhanced mainstem Klamath River spring flows during a critical time period for coho
salmon relative to observed flows for the POR.
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