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<br />To date none of the improvements recommended in the Gingery <br />plan have been implemented, as far as the CWCB knows. If those <br />changes were implemented, the IOO-year profile for the downstream <br />portion of Montrose Arroyo would be higher because water <br />currently leaving the channel upstream would be kept in the <br />channel. The Gingery study "proposed" IOO-year flood profile and <br />the Hydro-Triad profile are 2 feet higher at the point where the <br />Gingery existing IOO-year profile and the F.I.S. profile end. <br />Right now the lower profile more accurately represents what would <br />happen during a IOO-year flood. I recommend that we designate <br />the F.I.S. delineations for Montrose and Montrose County. I <br />recommend that, in view of the 2 foot differences being <br />insignificant in the incised channel, we retain the designation <br />of the Hydro-Triad delineation for that downstream reach below <br />the North 7th Street bridge. I suggest further that we clarify <br />this for the City and the County and that we get back with the <br />city about any plans they may have to implement the Gingery <br />proposals. We should also suggest that FEMA show the out-of-bank <br />flow continuing downstream until it reaches a stream and we <br />should recommend a detailed delineation for the downstream <br />portion of Montrose Arroyo. <br /> <br />d <br /> <br />Finally we come to Dry Cedar Creek. The stream is entirely <br />in the county. In the county F.I.S. some changes were made to <br />the profile, but they were not major changes. The changes were a <br />result of bridge codings. I recommend we designate the FEMA <br />profile there since it is more up-to-date. <br /> <br />A final problem is a drafting problem. For some reason <br />in going from a Preliminary F.I.S. to a Revised Preliminary <br />F. I. 5.' Dames & Moore printed the same sheet twice for Montrose <br />Arroyo and gave it two sheet numbers. The result is there is <br />currently no downstream sheet for Montrose Arroyo in the city <br />F.I.S. We can designate anyway, I think, and I am contacting <br />FEMA in Washington to get this careless error corrected. <br /> <br />In summary, it appears that FEMA should use or revise <br />existing detailed information on Cedar Creek and the downstream <br />portion of Montrose Arroyo rather than showing approximate <br />delineations. Where they have prepared revised detailed <br />delineations, I think we can generally live with them. I <br />disagree with showing IOO-year out-of-bank, shallow flooding as B <br />zone, but that may be fine with the city. I also disagree with <br />out-of-bank flooding that just stops where the mapping stopped. <br />I trust this helps clarify this confusing situation and I trust <br />we can pass this on to the local governments. <br /> <br />BRH/gI <br /> <br />-3- <br />