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nhc <br />Because of this effect, It Is not appropriate to simply sum up Lick Creek and the NF Teanaway flood flow <br />calculations. Rather, the hydrologic impact of realigning Lick Creek was evaluated by comparing <br />regression -predicted flows from a basin consisting of the catchment to the NF Teanaway River only, to <br />flows predicted from a basin consisting of the combined catchment of Lick Creek and NF Teanaway River <br />(Table 2). For example, when calculated separately, the predicted 2 -year flow for the Teanaway Is 849 <br />cfs, and 63 cis for Lick Creek. These two flows, determined separately, sum up to 912 cis which is 26 cis <br />more then the predicted value of 886 cis, when the basins of Lick Creek and the Teanaway River are <br />combined. This difference reflects the offset in timing between peak flows on Lick Creels and the <br />mainstem Teanaway River. The USGS regression equations have a large standard error, with an order -of - <br />magnitude spread between the upper and lower bound 90% confidence Intervals, and result in different <br />flows than the Effective Flood Insurance Study (FIS). They are believed, however, to provide a reasonable <br />estimate for the ratio of flows between the two basins. <br />Resulting changes in flow (increases from about 4% to about 5% between the 2- and 100 -yr floods) and <br />an estimated bedload transport rate (increasing from between 17% and 25%) are shown in Table 2. <br />These calculations provide an upper bound estimate of the potential increase in lateral channel <br />migration rates, suggesting that any increase In channel migration and bank erosion rates, due to the <br />Lick Greek realignment, are expected to be modest. As explained in the introduction, the estimated <br />change In the bedioad transport rate provides a conservative estimate of the expected change in bank <br />erosion and channel migration rate. The expected change in the migration rate Is substentlally less than <br />the computed 17% to 25% increase in bedioad transport rate. <br />Table 1: Basin Charactwistks Used to Estimate Flood Flows <br />Basin Area (miz) 87.8 6.1 93.9 <br />Annual Precipitation (in) 46.8 42.2 46.5 <br />Canopy Cover % 54.6 52.7 54.5 <br />Table 2: Chane In Hydrology (C6) and Estimated 8edload Transport Rate (q6) Due to the Change in <br />the Lkk Creels Confluence Location <br />2 <br />84$ <br />0.24 <br />886 <br />0.28 <br />4.4 <br />17 <br />5 <br />1,240 <br />1.4 <br />1,300 <br />1.7 <br />4.8 <br />21 <br />10 <br />1,520 <br />3.3 <br />11590 <br />3.9 <br />4.6 <br />19 <br />25 <br />1,880 <br />7.6 <br />1,970 <br />9.1 <br />4.8 <br />20 <br />5o <br />2,200 <br />13 <br />2,300 <br />16 <br />4.5 <br />25 <br />100 <br />2,490 <br />23 <br />2,620 <br />27 <br />4.8 <br />17 <br />Potential impact of Lick Creels relocation on the NF Teanaway River Morphodynamics 15 <br />