FLOOD03503

• County: Jefferson
• Community: Golden
• Stream Name: Tucker Gulch, Kenneys Run
• Basin: South Platte
• Title: Major Drainageway Planning
• Date: 9/1/1983
• Prepared For: Golden, Jefferson County
• Prepared By: UDFCD
• Contract/PO #: &&
• Floodplain - Doc Type: Floodplain Report/Masterplan

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SECTION V

and average annual flood damages were estimated. The estimated annual flood
damages provide the baseline condition for evaluating the economics of the

various alternative plans. Figure V-I shows the relationship between the

baseline condition and the residual flood damage curve for the selected

alternative pl an. The area between the two curves represents the annual

benefits in terms of flood damage reduction expected from plan implementation.

Alternative Plans

The screening process, referred to previously, was initiated by considering

the following alternatives plans:

SUMMARY OF PHASE A PLANNING EFFORT

Section I of this report documents the three-phase study effort which was
undertaken in completing the master planning project for Tucker Gulch and
Kenneys Run within the City of Golden and Jefferson County. The Phase A and
Phase B reports comprise the major drainageway planning portion of the
project. During the intial phase (Phase A) major flood problems were
identified and annual flood damages were estimated. Alternative solutions for
reducing or eliminating existing and anticipated flood hazards were screened
and eval uated re 1 at i ve to the economy of impl ementat ion. The Phase A report
also recommended an alternative plan for consideration by the local
governments and further development in Phase B.

A. Maintain the existing configuration.

B. A natural type waterway (where feasible) following the general
historic channel determined from old aerial photographs, old mapping,
and 1 oca 1 records.

During the course of the Phase A planning process, coordination meetings were
held with representatives of the Urban Drainage and Flood Control District,
City of Golden, Jefferson County, Adolph Coors Company and Muller Engineering
Company, Inc. The meetings were of key importance in this study phase, parti-
cularly in the initial screening of alternatives and in obtaining local input
regarding the project feasibility of the various alternatives being studied.

C.

The installation of major underground conduits along
course of the historic stream channel, using local
whenever possible.

the general
right-of-way

D. The use of lined flood channels to reduce right-of-way requirements.

The following paragraphs provide a brief summary of the Phase A planning
effort:

E. Selected or limited structural improvements or additions (culverts,
bridges, irrigation crossings, etc.) and channel improvements (re-
alignment, erosion control, low flow protection, maintenance access
ve 1 oc ity cont ro 1, etc.).

Floodplains and Flood Damages

F. Detention and/or retention facilities.

Hydrol ogi c and hydraul ic analyses were conducted to determi ne the magnitude,
frequency, and extent of flooding along the Tucker Gulch and Kenneys Run
drainageways. The floodplain information developed is presented in the FHAD
Report dated January, 1983.

G. Acquisition of flood prone properties and relocation of occupants.

H. Non-structural methods such as flash-flood warning, floodplain
regulation, flood insurance, evacuation plans, etc.

Using depth/frequency relationships from the hydrologic/hydraulic analysis,
flood damages were estimated within selected study reaches for the 2-, 10-,
and 100-year runoff events. F1 ood damage probabil ity curves were developed

I. Relocation of the channel to routes other than the historic channel.

J. Other plans as suggested by study participants.

K. Combinations of the preceding.

V-1