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<br />DepartmentofHousingandUrbanDevelopment(FederallnsuranceAdministration}
<br />in May, 1974,andrevisedonJallllary16,1976,whichalsoshowsthea;:>proxi-
<br />mate boundaries of the local flood haza~ areas. As this study utilizes
<br />accurate topographic mapping and detailed calculation of the flood water surface
<br />profiles, the study results presented herein are to be considered authoritative
<br />for purposes of floodplain information and floodplain management.
<br />
<br />All bridges and other significant structures that might divert or restrict
<br />flood flows, were surveyed. Additionally, because the digitized cross sections
<br />show the water surface elevation in each stream on the date of photography,
<br />the cross sections were adjusted by field measure~nts to reflect the streambed
<br />elevations and an area beneath the mapped water surface level for a discharge
<br />of 300 cfs in the stream at time of photography.
<br />
<br />Additional information concerning these maps and surveys ITldY be obtained fro~
<br />the Colorado Water Conservation aoard.
<br />
<br />Maps and Surveys
<br />
<br />Aerial photography and topographic maps for this study were prepared by
<br />land~rk Mapping Company, Denver, Colorado, in cooperation with the Co1or~do
<br />"ater Conservation Board. The mapping is at a scale of 1" ~ 200' with ground
<br />elevation contours depicted at an interval of two feet. Aerial photography
<br />wastakenonMay19,19S0. Ground control for map preparation was completed
<br />by Roundtree Engineers and Surveyors, Durango, Colorado. The ground control
<br />survey was performed to third order accuracy standards, or better, as defined
<br />by the U.S. Department of COlTfTlerce, Federal GeOdetic Control Cormittee. Mapping
<br />in th is s tudy com~ 1 i es with the "United States Nat i ona 1 M~ P Accuracy Standards".
<br />Field Checks of the maps were conducted by Colorado water Conservaticn Board
<br />perSOnTlel.
<br />
<br />Flood Insurance
<br />
<br />The National Flood Insurance Program is a Federal program that enables property
<br />owners to buy flood insurance at a reasonable and subsidized cost. In return,
<br />communities are required to carry out floodplain management measures to protect
<br />lives and new construction from future flooding.
<br />
<br />Flood insurance through the Emergency Phase of the National Flood Insurance
<br />Program has been available to all resictents of Montezuma County since Februory 3.
<br />1976. and the Town of ~ancos since July 25, 1975.
<br />
<br />Forty permoncnt control ~~rks were ;et with;n the study JreJ for use in deter-
<br />miningsitee1evationsbyfieldsurveymetnods. Seven permanent control
<br />markers are described in Table 6 an~ are intended for use only in conjunction
<br />with this report.
<br />
<br />no ~~"~'\';M ,~"'~,~~~ ~~,,~~'ncs a"d subsidiz,,<j ,,~.~< ",.~ "v,il~hl~ ,,~<1~r th~
<br />'''" ,~,,". ,.., ,,,'~,~,,~~ ""._,-~-
<br />
<br />Emergency Phase, effective October I, 1981:
<br />
<br />The cross sections for the study were obtained by both photogrammetric and
<br />fi~ld survey r.Jethods. The cross sections, with al ignments shown on the maps,
<br />were used in the hydraulic analysis todetemine the water surface profiles
<br />shown in this report. A total of 53 digitizen cros~ spr.tion, wprp used in the
<br />hydraulic computations on tne Mancos River and Chicken Creek.
<br />
<br />Single Family ~esidential
<br />Other Residential
<br />Contents, Residential
<br />Smallilusiness
<br />ContentS,Srla11 Business
<br />Gthef ~on~res;dential
<br />C(jnten~s, Other- Non-
<br />residential
<br />
<br />-5-
<br />
<br />Total Coverage
<br />Available
<br />
<br />SUbsidized
<br />Rate per $1QO
<br />of Coveraqe
<br />
<br />$ 35,000
<br /> 100,000
<br /> 10,000
<br /> 100,000
<br /> 100,000
<br /> 100,000
<br /> 100,000
<br />
<br />S .40
<br />.40
<br />.;0
<br />.50
<br />1.00
<br />.50
<br />
<br />1.00
<br />
<br />-,-
<br />
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