FLOOD07170

• County: El Paso
• Community: Manitou Springs
• Stream Name: Fountain Creek
• Basin: Arkansas
• Title: Hydrology for FEMA, Phase II
• Date: 2/1/1994
• Prepared For: FEMA
• Prepared By: RCE
• Floodplain - Doc Type: Floodplain Report/Masterplan

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10. UNION AND FILMORE DRAINAGE

10.1. General Description

The Union and Filmore drainage area is located in the northeast portion of the city of Colorado
Springs, The drainage is bounded by Constitution Avenue to the south, Hancock Street to the West,
Templeton Gap Drainage basin to the north, and the Sand Creek drainage area to the east (Figure
10.1),

A portion of the flow from the drainage area is captured by the Van Buren diversion channel
which runs along Constitution Avenue, The remainder of the storm runoff continues beyond the Van
Buren channel and is tributary to the Shooks Run basin,

The Union and Filmore drainage comprises a total of 2,03 square miles. The upper portion of
the watershed is undisturbed and consists of grasses and woodlands, The lower portion of the
watershed is developed primarily as residential housing, Within the developed lower portion of the
basin are several open areas including a golf course,

10.2. Previous Studies

Previous studies in the area include the hydrologic modelling of the Union and Filmore drainage
area in conjunction with the Shooks Run basin by Wilson & Company (Ref. 10.1), This study used
the TR20 model to estimate runoff from the 10- and 100-year, 24-hour rainfall events, JR Engineering,
LId, studied a portion of the basin as part of the Lower Cragmore Master Drainage Plan (Ref. 10,2),
This basin abuts the west boundary of Union and Filmore basin. In addition, hydrology at the
intersection of Union and Filmore Streets was studied by Drexel Barrel as part of the Master
Development Drainage Plan for the Houck Estate at Union and Filmore (Ref. 10,3), Table 10.1
presents a summary of these studies '

10.3. Hydrologic Analysis

The Union and Filmore drainage was analyzed using the TR-20 modei (Ref. 1.2), The data
deck was obtained from Wilson & Company (Ref, 10,1), This model was reviewed and revised to
more accurately estimate the existing conditions, Curve numbers and reach routing parameters in the
original deck were not modified; however, T c values were independently computed, The revised
model was then used to estimate runoff from the 100-year, 24-hour event.

10,1 Resource Consultants & Engineers, Inc,