FLOOD10386 ‎(2)‎

• Designation Number: 576
• County: Gilpin
• Community: Black Hawk
• Stream Name: North Clear Creek, Gregory Gulch and Chase Gulch
• Title: Floodplain Information Report - Black Hawk
• Date: 7/1/2004
• Prepared For: Black Hawk and CWCB
• Prepared By: Love and Associates
• Floodplain - Doc Type: Floodplain Report/Masterplan

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Verticle datum for
standard, NA VD

the FIRM and FIS is NGVD 1929
1988. add 4.S feet to all elevations

To convert
(USCOE, 2000)

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to

Approximate floodplains for the upper reach of Fourmile Gulch and for North Clear
Creek below City limits are shown because these reaches have not been studied with
sufficient technical detail to be used for floodplain delineation with any certainty. FEMA
requires a detailed floodplain analysis for development projects greater than S acres in
area or more than SO units in size in approximate floodplains be performed by a
professional engineer.

the

most

recent

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Updated 100-year floodplains shown on Figures SA and SB within the City of Black
Hawk are based on detailed technical methods, with the exception of the approximate
floodplain for the upper reach of Fourmile Gulch which is based on the 1984 FIRM.
North Clear Creek downstream of City limits are shown on Figure Sc. Additional
information including flood profiles and base flood elevations may be found in the PMR
(Love & Associates, Inc., 2003).

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Flood

An approximate floodplain along North Clear Creek downstream of City Limits to North
Clear Creek is shown on Figure sc. It is defined using normal depth calculations of three
cross sections shown on Figure SC obtained from USGS topographic maps. Please refer
to the Appendix. These floodplains are shown for planning purposes only, and
development or construction in the area of approximate floodplains should be studied by
detailed topographic and hydraulic analysis.