Laserfiche WebLink
<br />GONTRO~ <br />OQ C/o <br />o l'i' .....,Ilr ill..... <br />it nt"s1ll ~ <br />o 0 <br />2 TID -;/ <br />1!1 <br />"b ~ <br />~""/l>'l:/a ~-.j# <br /> <br />Board oj Direclors <br />ExecutIVe Commillee: <br /> N <br /> Calhy Reynolds 0 <br /> ~ <br /> Chairman 0 <br /> City of Denver 0 <br /> < <br /> Ruth A. Correll " <br /> 0 <br />Chairman Pro-Tern " <br /> City of Boulder 0 <br /> u <br />Steven E. Cramer " <br /> Secrelary ill <br /> > <br /> Adams County z <br /> ill <br /> 0 <br /> Arlen E Palton <br /> Treasurer <br /> Engineer ill <br /> " <br /> Eugene L Otis z <br /> ill <br /> Member > <br />City of EnglewOOd < <br />r <br /> ~ <br /> Members w <br /> N <br /> ;i <br /> Roberl Brooks 0 <br />Arapahoe County ~ <br />~ <br /> N <br /> David A Day <br /> Engineer <br /> W. G. Duncan m <br /> Douglas County m <br /> ~ <br />Rich Ferdinandsen ill <br /> Jefferson County C <br /> ~ <br /> Josie Heath "' <br /> Boulder County <br />George A. Hovorka , <br />City of Westminster , <br />N <br /> m <br /> FederiCO Pena ~ <br /> Crty of Denver ~ <br /> ~ <br />M. L "Sam" Sandos ill <br /> Clly of Denver z <br /> 0 <br /> Paul SwaIm I <br /> ~ <br /> City of Denver ill <br /> " <br /> Rex Swann ill <br /> , <br />City of Edgewaler <br /> <br />L. Scott Tucker, Executive Director <br /> <br />TO: <br /> <br />M.y I, 1981!~ <br />a l.:j. ,..0SVrJ'7 <br />A 11 Holders of Urban Storm C'OI1t~0-94 .. /J81 <br />Drainage Criteria Manual '-9!/,q'f/olf, <br /> <br />Ben Urbonas . ~~_::::/OI1t ;4'-9 <br />Chief, Master Plannlng Program c_-~.- :.?O <br /> <br />FROM: <br /> <br />SUBJECT: May 1, 1984 Revisions to Manual <br /> <br />Accompanying this memorandum are the following May 1, 1984 <br />revisions to the Urban Storm Drainage Criteria Manual: <br /> <br />1. Volume 1, "RAINFALL". Entire Chapter <br />2. Volume 1, "RUNOFF". Entire Chapter <br />3. Volume 1, "STREETS". Revised Figures 6-2 and 8-2. <br />4. Volume 2, "MAJOR DRAINAGE". Revised Paragraphs 5.4.2, 5.4.4, <br />and 5.4.5 of "Riprap" (Section 5). <br /> <br />Replace the revised chapters, figures, and paragraphs currently in <br />your manual with the accompanying respective chapters, figures and <br />paragraphs. I suggest you either void or destroy the old pages being <br />replaced. <br /> <br />Items 1 and 2 above represent a very comprehensive analysis of <br />rainfall/runoff data collected in and near the Urban Drainage and Flood <br />Control District. These two chapters significantly revise the hydrology <br />analysis procedures for the Denver metropolitan area. The revisions are <br />based on a locally collected hydrologic data base over a 10-year period. <br />As a result, the revised methodology can be considered to be "regionally <br />cal ibrated" and state-of-the-art as we currently understand it. It is <br />our hope that you find it usefull and that it will provide more accurate <br />and more consistent urban runoff calculations for the Denver <br />metropolitan area. <br /> <br />Item 3 represents a correction needed to further limit the amount <br />of "street flow" during the major storm events. It is hoped that this <br />revision will improve the safety to public and reduce damages during the <br />large rainfall events. <br /> <br />Item 4 provides for a safety factor in the design of riprap channel <br />linings. The earlier revision to of the riprap section was, in part, <br />based on studies by C.D. Smith in Canada. However, after reexamininq <br />his publications, we concluded that C.D. Smith's equations were based on <br /> <br />.. ~l <br />