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Biological Opinions - Bureau of Reclamation

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Provide Project irrigation deliveries to:<br />

• Klamath Drainage District (Area A2 from North Canal and Ady Canal)<br />

• Lease Lands in Area K (Area A2 from Ady Canal)<br />

• Lower Klamath National Wildlife Refuge (from Ady Canal)<br />

To satisfy these goals for fall/winter water management, <strong>Reclamation</strong> will determine a flow<br />

release target from Link River Dam in real-time, using the series <strong>of</strong> steps and equations<br />

described below. The flow release target from Link River Dam combined with accretions<br />

downstream from Link River Dam is intended to provide at least minimum daily target flows<br />

below IGD, and flows greater than minimums when hydrologic conditions allow. IGD proposed<br />

average daily minimum target flows are 1,000 cfs (28.3 m 3 /sec) in October and November, and<br />

950 cfs (26.9 m 3 /sec) in December, January, and February.<br />

In several water years during the POR, the model simulates a number <strong>of</strong> daily flows at IGD that<br />

are less than the minimum daily average target flows. This is because the model simulates a oneday<br />

time lag between flow releases at Link River Dam and flow at IGD. The one-day time lag<br />

combined with variability in accretions results in simulated flows lower than the minimum<br />

targets. Real-time implementation <strong>of</strong> the proposed action will result in increased releases from<br />

Link River Dam to ensure that flows meet or exceed the daily minimum average target flows at<br />

IGD. In addition, to allow flexibility for the possibility <strong>of</strong> operator error and uncertainties<br />

associated with flow releases at IGD, <strong>Reclamation</strong> proposes a maximum <strong>of</strong> a 5 percent reduction<br />

in flows below the minimum daily average flows at IGD, for up to a 72-hour duration. If such a<br />

flow reduction occurs, <strong>Reclamation</strong> proposes that the resulting average flow for the month will<br />

meet or exceed the associated minimum daily average flow (<strong>Reclamation</strong> 2013b).<br />

Flow in the Williamson River is the primary hydrologic indicator used to calculate a release<br />

target for Link River Dam. As described in more detail below, the initial calculated Link River<br />

Dam release target is modified based on several factors, including (1) magnitude <strong>of</strong> Williamson<br />

River flow, (2) rate at which UKL is filling, (3) accretions to the Klamath River below Link<br />

River Dam, and (4) any EWA carried over from the previous water year. Williamson River<br />

flows used in the modeling environment and during real-time operations are based on daily<br />

average flow at the U.S. Geological Survey (USGS) gage number 11512500 (Williamson River<br />

below Sprague River, near Chiloquin, Oregon).<br />

4.2.3.1.1 Williamson River Proportion<br />

The previous day’s Williamson River average flow is multiplied by the appropriate proportion to<br />

calculate an initial Link River Dam flow release. The proportion <strong>of</strong> the Williamson River flow<br />

used to calculate the daily Link River Dam target release is adjusted based on the magnitude <strong>of</strong><br />

the current Williamson River flow and the month. Higher Williamson River flow results in a<br />

greater proportion <strong>of</strong> inflow released at Link River Dam and lower Williamson River flow<br />

results in a lower proportion released. The flow proportion multipliers corresponding to specific<br />

Williamson River flows are presented in Table 4.2. Intermediate flow proportion multipliers are<br />

obtained by linear interpolation.<br />

18

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