FLOOD00850

• Designation Number: 31
• County: Arapahoe
• Community: Unincorporated Arapahoe County
• Title: Major Drainageway Planning - Little Dry Creek, Report, Volume I
• Date: 2/1/1974
• Designation Date: 6/1/1974
• Floodplain - Doc Type: Floodplain Report/Masterplan

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IMP R 0 V E MEN T S

AND

C 0 S T S

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The proposed solution to the Little Dry Creek drainage problem for which

preliminary plans and cost estimates have been prepared requires both

flood plain zoning and capital improvements. In areas of the watershed

which are still open or sparsely urbanized, it is self-evident that pre-

sent natural waterways should be reserved to the maximum extent possible

to convey future flood flows through the basin as they have in the past.

Future urban development should be restricted to lands lying above

anticipated flood levels. Where urban or other development has already

taken place in natural floodways: channelization, conduits, detention

dams, or other capital improvements are required to protect existing

property from flood damage.

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Effective urban planning and the development of workable flood zoning

ordinances both require that design flood limits be defined along the

major drainageways in the basin in areas where such development may

occur. Where development has already occured, the design flood limits

are required to show the extent of the flood protection provided by the

proposed capital improvements. The flood limits that can be expected

under estimated future urbanization conditions in the basin without

improvements to present drainage facilities are also of interest. The

two flood limits plotted on the same maps clearly show the effectiveness

of the proposed capital improvements in reducing the urban area that

could otherwise be expected to be flooded.

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Flood Plain Zoning

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The lOO-year flood levels that can be expected on the major waterways in
the Little Dry Creek basin under estimated conditions of future basin
urbanization are shown with and without the proposed drainageway capital
improvements in Volume II of this report on the 1" = 200' scale plan-
profile sheets, Drawings 4 through 29. It will be seen that few channel
improvements will be needed above the City of Englewood if effective flood
plain zoning can be effected at this fairly early stage of basin urbani-
zation.

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