FLOOD08233

• County: Gilpin
• Community: Black Hawk
• Stream Name: North Clear Creek
• Basin: South Platte
• Title: LOMR - Affected Panel 080076 0001 B - Case No. 98-08-310P
• Date: 11/9/1998
• Prepared For: Black Hawk
• Prepared By: FEMA
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

CHANGES ARE MADE IN DETERMINATIONS OF BASE FLOOD ELEVATIONS FOR THE CITY
OF BLACK HAWK, GILPIN COUNTY, COLORADO, UNDER THE NATIONAL FLOOD
INSURANCE PROGRAM

On October 16, 1984, the Federal Emergency Management Agency identified Special Flood Hazard Areas
(SFHAs) in the City of Black Hawk, Gilpin County, Colorado, through issuance of a Flood Insurance Rate
Map (FIRM). The Mitigation Directorate has determined that modification of the elevations of the flood
having a I-percent chance of being equaled or exceeded in any given year (base flood) for certain locations
in this community is appropriate: The modified base flood elevations (BFEs) revise the FIRM for the
community. .

The changes are being made pursuant to Section 206 of the Flood Disaster Protection Act of 1973 (Public
Law 93-234) and are in accordance with the National Flood Insurance Act of 1968, as amended (Title XIII
of the Housing and Urban Development Act of 1968, Public Law 90-448), 42 U.S.C. 4001-4128, and
44 CFR Part 65.

A hydraulic analysis was performed to incorporate the following projects associated with construction of
a hotel/casino between North Clear Creek and Main Street: culvert construction under Richman Street
between State Highway 119 and Main Street, channelization of North Clear Creek from approximately
1,120 feet downstream to approximately 1,620 feet downstream of Gregory Street, construction of an
8-foot-diameter bypass pipe that parallels the entire length of the channelization project, and construction
of an inlet structure at the upstream end of the bypass pipe and channelization project. This .has resulted
in a decrease in SFHA width and increased BFEs for North Clear Creek. The aforementioned channelized
portion of North Clear Creek contains the base flood. The table below indicates existing and modified
BFEs for selected locations along the affected lengths of the flooding source(s) cited above.

Location

Existing BFE
(feet)*

Modified BFE
(feet) *

Approximately 2,030 feet downstream of Gregory Street
Approximately 1,460 feet downstream of Gregory Street
Approximately 675 feet downstream of Gregory Street

7,990
8,006
8,027

7,990
8,018
8,031

*National Geodetic Vertical Datum, rounded to nearest whole foot

Under the above-mentioned Acts of 1968 and 1973, the Mitigation Directorate must develop criteria for
floodplain management. To participate in the National Flood Insurance Program (NFIP), the community
must use the modified BFEs to administer the floodplain management measures of the NFIP. These
modified BFEs will also be used to calculate the appropriate flood insurance premium rates for new
buildings and their contents and for the second layer of insurance on existing buildings and contents.

Upon the second publication of notice of these changes in this newspaper, any person has 90 days in which
he or she can request, through the Chief Executive Officer of the community, that the Mitigation
Directorate reconsider the determination. Any request for reconsideration must be based on knowledge
of changed conditions or new scientific or technical data. All interested parties are on notice that until the
90-day period elapses, the Mitigation Directorate's determination to modify the BFEs may itself be
changed.