FLOOD06569

• Designation Number: 425
• County: Fremont
• Community: Coal Creek
• Basin: Arkansas
• Title: Floodplain Information Report - Flood Hazard Boundary Map - Coal Creek, CO
• Date: 4/1/1996
• Designation Date: 5/1/1996
• Floodplain - Doc Type: Floodplain Report/Masterplan

.

.

.

TABLE!

Drainage areas of streams within the Town of Coal Creek

'StreaQi'
Coal Creek

'Dra1pageArea (sq mi)
9.8

Upstream corporate limit of the Town of Coal
Creek
Downstream corporate limit of the Town of Coal
Creek
Confluence with Coal Creek
Confluence with Coal Creek
Confluence with Coal Creek
Confluence with West Tributary

Coal Creek

11.2

Southeast Tributary
Southwest Tributary
West Tributary
Subtributary to West
Tributary

0.28
0.54
0.57
0.07

TABLE 2
Estimated lOO-year peak flows for Coal Creek within the Town of Coal Creek
and calculated lOO-year peak flow for Coal Creek at Florence

','[iPrijm~g~N'~~:<~.q'mi),
9.8

, ,'lO:Q:YellrfeakiFlow (efs)
4,835

Coal Creek at upstream corporate limit of
the Town of Coal Creek
Coal Creek at downstream corporate limit of
the Town of Coal Creek
Coal Creek at its confluence with the
Arkansas River in Florence '

11.2

5,270

18.1

7,400 *

*

Flow calculated by detailed methods as part of the Florence Flood Insurance Study

A procedure for determining hydrology information for approximate floodplains of lakes, ponds,
local drainages, and streams with drainage areas smaller than the range of applicability for the
Guidelines (smaller than 1 square mile for Subregion ARK-3) has not been established. The
hydrologic methodology developed in the Guidelines is appropriate for designation and approval of
approximate floodplain information and for use in simple floodplain analyses for development such
as open space, agriculture, fann bridges, pole barns, and individual single residential structures.
The methodology is not appropriate for development involving residential subdivisions greater than
50 lots or occurring on sites greater than 5 acres, commercial construction, industrial construction,
construction of public transportation facilities, or construction of flood control facilities.

The Town of Coal Creek should regulate the approximate floodplains on a case-by-case basis
subject to a detailed hydrologic and hydraulic analysis. A detailed floodplain analysis may be
required in certain cases. The detailed analysis should be performed by a professional engineer and

6