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<br />. <br /> <br />. <br /> <br />flood history, magnitudes and frequencies as nearly as possible, Where <br />these factors are based on historical records, there seldom is much <br />controversy or difference on this item. However, unfortunately, histor- <br />ical records are not available at many places where these factors are <br />required by the planning or designin~ parties, This fact must be recog- <br />nized and although full support should be given to improving the quantity <br />and quality of historical records of basic hydrologic data, such as the <br />program outlined in the A'NR report, it should be further recognized that <br />such records probably will never be completely adequate to supply all <br />the needs, It is, therefore, necessary to develop certain factors such <br />as magnitudes and frequencies of floods on what might be termed an em- <br />pirical basis. When this is necessary, the results are materially af- <br />fected by the choice of methods as well as matters of judgment in the <br />application of the methods, Hence, there is ground for honest differences <br />of opinions between individuals as well as organizations, Unless the <br />same factors are assumed in the planning and designing of projects and <br />programs that are closely related hydrologically, it is impossible to <br />arrive at a fully integrated and coordinated ulan for a watershed. <br />This item ce,used a, great c,eal of controversy dl'ring the preoaration of <br />the AWR report. Various special studies were set UD to help resolve <br />tlmse controversies but only limited success was achieved, The im- <br />portance of this item anc! the difficulty in solving the problem must <br />be recognized. Various interests have used diff~rent procedures for <br />many years and have compiled a great deal of inf0rmation based on <br />those procedur0s. Since theso procedures w?rG developed on an in- <br />dividual agency or interest basis, they ar'" nCltt\Tally quite dissimilar <br />in many respects even though, 'JS has be~n f,)und In m2l1Y instances, the <br />proceduns frequently give answers scrprisingly closo together and well <br />within the accuracy to be rJasonably expected of such procedures, A <br />hydrologist should not be criticized for ~uestioning results obtained <br />by procedures with which he is not f~~iliar or with which he does not <br />agree, Procedures, at least as far as the Federal agencies are con- <br />cerned, are usually aoplied within the framework of procedural guides, <br />such as handbooks, which have been adopted by the respective agencies <br />for nation-wide use through administrative action; ther2fore, the <br />agencies working within a soecific watershed are not freo to ignore <br />these national guides that have been set up on an agency bas'Ls,. Con- <br />sidering the' results of sueci?l studies conducted in the AWR, as well <br />as regional or watershed efforts that have been attempted in other <br />parts of the country, it does not seem that the policy and procedural <br />problems inherent in this item cen be resolved at field level or on a <br />regione.l or riv3r basin basis, The former AWR Committee recognized <br />this fact and so rcport"d to its parent committee, the Fed"ral Inter- <br />Agency River Basin Committee in Washington, Given the proper national <br />guidelin~s and administrative actions on the policy and procedural <br />questions, procedur::>s to aceomplish this item in specific watersheds <br />can be established, However, until such national policy and administra- <br />tive action is forthcoming, it is bcliev8d that little progress on <br />this item can be made at field level, <br /> <br />- 4 - <br />