Laserfiche WebLink
<br />21 <br />have been identified, and those where substantial floodplain occu- <br />pation has occurred. This grouping is shown on Table 11-4, From this <br />exercise we see that the number of Dec"ision Units requiring more <br />careful study is reduced to 12. Where a dam site is possible, the <br />basic decision is "dam or no dam," Then there remain only six <br />reaches with substantial flood hazard for careful study. Each of <br />these is affected by the decision to p"lace a dam upstream, <br />The basic classes of alternatives to consider are selected <br />according to Table 11-5, With the Decision Units shown there are <br />still too many combinations for analysis. Table 11-6 shows the dams <br />which influence various Decision Units. Using this information, a <br />few combinations of dams can be tested to show the range of possi- <br />bilities without testing each alternative exhaustively, <br />To test this, three basic dam combinations are selected: <br />Six Dams = All Dams <br />Two Dams = Holly and Engl ewood Dams Only <br />No Dams <br />This reduces the number of alternatives further since not all cams <br />affect all Decision Units, The information on Table 11-6 now (an <br />be converted as shown in Table Il-7 giving the dam alternative" <br />which must be considered for the Decision Units, These result in <br />16 different flow regimes caused by the presence or absence of flow <br />regulation by the dams, These resu'lt from upstream decisions <br />regarding the dams. <br />The type of treatment afforded the downstream reaches is sub- <br />stantially independent of the decis'ions about dams, Decisions <br />regarding treatment type can be made on the merits of the individual <br />