FLOOD02900

• County: Adams
• Community: Commerce City
• Basin: South Platte
• Title: Lower First Creek and Direct Flow Area 0055 Major Drainageway Planning
• Date: 5/1/2002
• Prepared For: UDFDC
• Prepared By: Turner Collie & Braden Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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AGENDA

TumerCeIlie<f5Braden Ine.

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First Creek OSP and FIL-\D
(Kickoff Meeting)
Time: 3:00
Date: August 24, 1999
Location: Urban Drainage & Flood Control District

MEETING MINUTES

Subject:
Job No.:

Lower First Creek and Direct Flow Area 0055 Outfall Study
35.05096-040

Introduction

Place: Urban Drainage and Flood Control District Offices
Date & Time: 8/24/99 3:00 PM

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Attendees:

David Mallory (UDFCD) Bill DeGroot (UDFCD)
Edward Stafford (Commerce City) Rich Ommert (TCB)
Rick Moser (TCB) David Center (TCB)
Mark Omoto (Adams County) Stu Williams (Denver)
Henry Butler (American Realty Trust Park field)
Ken Schm idt (park field) Stephen Smith (RIvIA)
Tom Jackson (RMA, USFW) Rich Urbanowski (BR W for Forest City)
Tim Kilgannon (Rt\-lA)

Hydrology
Base Condition
Future Condition
Existing Condition

Detention Areas

Pre parer:

David Center

Date: 8/25/99

Project Contact List

The purpose of the meeting was to "kickoff'the Outfall Planning Study and Flood Hazard Area Delineation for the
lower First Creek watershed.

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Next Meeting/Adjournment

Hydrology
Prior to the meeting, Dave Mallory provided TC&8 with the current I OO-yr CUHP and UDSWM data input files for
the watershed. TC&8 ran these data sets through the CUHP and UDSWM programs. The results did not match the
results reported in the Martin/Martin study for the upper watershed. TC&8 will investigate the reason for this.

The study will include three hydrologic models. First, the Base Condition will include the CUHP subwatersheds
and UDSWM routing elements as defined by the Upper First Creek Plan (by Martin/lvlartin). UDFCD will provide
the data sets to TC&8 for the needed return perio<!s. TC&8 will verify land use percent impervious assumptions
and subwatershed delineations. For the second hydrologic model, Future Condition, all detention basins (except
for constructed or soon to be constructed basins) will be removed from the Base Condition model and the future
percent impervious basin conditions will be simulated. For the third hydrologic model, Existing Condition, the
Future Condition model will be revised to simulate the existing watershed condition percent impervious values.

Detention Areas
The feasibility of using areas within the Rocky Mountain Arsenal (RMA) for flood control detention was briefly
discussed. RMA has started grading within Borrow Area #10. This area along with the Bald Eagle Shallows area
within RMA could be considered for detention. The RMA can provide mapping and preliminary plans for the
potential detention areas.

RMA would like to know the approximate flood control volume that will be necessary. Dave Mallory stated that the
volume necessary would be approximately 200.300 acre-feet. TC&B will determine the actual number based on the
results of this study.