FLOOD05827

• County: Boulder
• Community: Boulder
• Stream Name: Boulder Creek
• Basin: South Platte
• Title: Boulder Creek Phase B
• Date: 12/1/1979
• Prepared For: Boulder
• Prepared By: UDFCD
• Floodplain - Doc Type: Floodplain Report/Masterplan

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of Boulder. The Boulder City Council rejected both alternatives

Engineers to conduct a new study under the authority of the pre-

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and instead preferred a diversion channel along a major street that

viously authorized Boulder Creek Local Protection Project.

stead, the new feasibility study was incorporated into the Metro-

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would have a benefit-cost ratio of about 0.6.

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The Boulder CECEP Subcommittee, in September of 1973, outl ined a

politan Denver and South Platte River and Tributaries Study, which

was then getting underway. The hydrology of the Boulder Creek

Basin was restudied in conjunction with this report using the

Environmental Protection Agency's Storm Water Management Model

(SWMM). Historical stream gaging records were used to check the

results obtained from SWMM. The results of the restudy revised the

estimated 100-year discharge from 7,400 c.f.s. to 12,000 c.f.s.

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12-point flood control plan as an alternative to plans presented

earlier by the Corps of Engineers. Their plan was to implement a

major program to reduce the flood hazard in Boulder using, for the

most part, a nonstructural approach based on advanced flood plain

management methods. The plan included field marking of the flood

plain and relocation, acquisition, razing, and flood-proofing of

existing structures. The goal of the CECEP plan was to obtain a

50- to 75-percent flood damage reduction. The plan also included

flood-proofing and regulation of future development, an early

warning system, and minor structural improvements. The CECEP plan

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was based on a 100-year discharge of 7,400 c.f.s.

Flood control feasibil ity studies on Boulder Creek were conducted

during the course of study for Plan I based on an enlarged channel,

Plan 11 based on an excavated floodway, and Plan I I I hased on

flood-proofing and relocation. Plan 1 I I represents the alternative

favored by the Boulder Creek Subcommittee.

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The Boulder City Council adopted the CECEP Subcommittee's plan in
1974. A resolution adopted by the City Council on 20 Agusut 1974
requested implementation of the plan under provisions of Section 73

Plans I, I I, and I I I were presented to the citizens of Boulder in a

series of eleven publ ic presentations and two days at a shopping

center information booth in April 1977. Subsequent to the meetings,

the Boulder City Council conducted two publ ic meetings to sol icit

citizen reactions. After considering the views of the publ ic, The

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of Public Law 93-251.

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The local plan was a major departure from the Boulder Creek Project

authorized by the Flood Control Act of 1950 and would, therefore,

require authorization by the Congress. In view of the need for

h . . f 1 wh',ch m'lght result from a
Congressional aut orlzatlon 0 any p an

new feasibil ity study, it was deemed inappropriate for the Corps of

City Council expressed preference for the concepts of the excavated

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floodway-based plan (Plan II) from the canyon mouth downstream to

17th Street and a combination of the excavated floodway-based plan

(Plan II) and relocation/flood-proofing-based plan (Plan III) from

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.

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