FLOOD08965

• County: Jefferson
• Community: Golden
• Stream Name: Lena Gulch
• Basin: South Platte
• Title: LOMR - Affected Panel 080090 0002 A - Case No. 00-08-375P
• Date: 5/3/2001
• Prepared For: Jefferson County
• Prepared By: FEMA
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

CHANGES ARE MADE IN DETERMINATIONS OF BASE FLOOD ELEVATIONS FOR THE CITY
OF GOLDEN, JEFFERSON COUNTY, COLORADO, UNDER THE NATIONAL FLOOD
INSURANCE PROGRAM

On May 15, 1985, the Federal Emergency Management Agency identified Special Flood Hazard Areas
(SFHAs) in the City of Golden, Jefferson 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 updated topographic information along Lena Gulch to
establish BFEs and to modify the SFHA boundary delineations along Lena Gulch from approximately
4,000 feet downstream to approximately 1,900 feet downstream of U.S. Highway 6, This has resulted in
increases and decreases in SFHA width for Lena Gulch. In addition, in the right overbank area of the
main channel, a divided flowpath occurs along the Lena Gulch Overflow Area from approximately
3,600 feet downstream to approximately 1,800 feet downstream ofU,S. Highway 6, This area has been
designated Zone AH, an SFHA subject to shallow base flooding with depths between I foot and 3 feet
and with BFEs determined. The table below indicates existing and modified BFEs for selected locations
along the affected lengths ofthe flooding source(s) cited above,

Location

Existing BFE
(feet)*

Modified BFE
(feet)*

Lena Gulch:
Approximately 3,550 feet downstream ofU,S. Highway 6
Approximately 1,800 feet downstream of U.S. Highway 6

None
None

5,835
5,874

Lena Gulch Overflow:
Approximately 1,600 feet downstream ofU,S, Highway 6

None

5,876

*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.

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