FLOOD04286

• Designation Number: 23
• County: Adams
• Community: Westminster
• Stream Name: Big Dry Creek
• Basin: South Platte
• Title: Major Drainageway Planning - Master Plan - Big Dry Creek - Westminster - Volume I
• Date: 3/1/1973
• Designation Date: 7/1/1973
• Floodplain - Doc Type: Floodplain Report/Masterplan

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were allowed to make decisions on an alternative to be dealt with in detail
In the second phase. Phase B then became the datai led master planning and
report preparation phase of the contract.

An out line of the Scope of Work I '; as fo liONS:

A. Development of alternative plans.

I. Meet wi th I oca I governmenta lent i ty ,'eprllsentat i ves on future
land planning, collect basic dilta, and maintain contact with the
United States Corps of Engineers.

2. Perform hydrological studies for 5, 25, and IOO-year recurrence
intervals, and prepare flood hydrographs. Also estimate annual
flood damages and perform llppropri,ate hydraulic computations.

3. Review right-of-way aspect> relative to flood hazard.

4. Determine various potential alternate solutions and analyze for
costs and benefits.

5. Review legal aspects of pl~ns and present flooding hazard.

6. Prepare a short written report to summarize Phase A work prior
to Phase B work.

B. Prel imlnary Design.

J. Prepare final hydrological studies to determine the magnitude
and volume of flood runoff for design purposes,.

2. Develop des ign criteria for the subject project.

3. Process suitable topographic mclpplng having a I" ~ 200' scale
with a contour intervals of two Fe"t for plan and pl-ofile purposes.

4. Develop the approximate chetnnel and flood pl.ain requirements for
review by local officials.

5. Prepare plan and profiles of the stream channel and flood plain
complete with flood profile water s,urface elevations.

6. Prepare preliminary design drawings with a suitable written report.

BASIN PROBLEMS AND OPPORTUNITIES

The Big Dry Creek basin Is the largest urban basin undertaken to date
for master planning by the District. At th.. pres"nt time it: is mostly