FLOOD06478

• County: Boulder
• Community: Boulder
• Stream Name: Skunk Creek
• Basin: South Platte
• Title: Request for LOMR
• Date: 1/1/1989
• Prepared For: Boulder County
• Prepared By: Love & Associates, Inc.
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

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Request for Letter of Map Revision - Skunk Creek
University of Colorado at Boulder Research Park
Page 3

2.3 Prin~ipal Flood Problems

Prior to the construction of the Skunk Creek Channel
Improvements, Skunk Creek had several potential flooding
problems. Flood waters from the Skunk Creek floodplain would
flow over and under Colorado Avenue as they enter the UCBRP.
Similar conditions existed at Foothills Parkway where waters
from the Skunk Creek floodplain would flow over the road as
they leave the UCBRP. The area was sparsely developed and
little to no property damage occurred during flooding
conditions.

2,4 Flood Protection Measures

The Skunk Creek Channel Improvement Project, from the
existing box culvert at Foothills Parkway to the existing
upstream box culvert at Colorado Avenue is comprised of
upstream and downstream transitions and a lOO-year flood
channel. The downstream transition is accomplished by
allowing the existing culvert under Foothills Parkway and the
road embankment of Foothills Parkway and Arapahoe Avenue to
govern the floodplain hydraulics (as they did under previous
conditions). Upstream, a lOO-year spill collection channel
has been constructed near Colorado Avenue in order to collect
overland flows and convey them to the improved Skunk Creek
channel. The Skunk Creek channel will convey the 100-year
flows, allowing for site development and minimal debris
clean-up after floOding. The sole purpose of this project is
for flood control and wetland mitigation. A U.S. Army Corps
of Engineers 404 Permit has already been obtained by the
University for this project (Ref. 5).

This study demonstrates the intent to reduce flood hazard by
the construction of flood protection measures on Skunk Creek.
Detailed as-built drawings of the improvements are included
in this submittal package (Ref. 2). No existing structures
will be inundated by a lOO-year flood (future basin
conditions) during or after the construction of the Skunk
Creek Channel Improvements Project. Downstream properties
will not be impacted by sediment transport as the constructed
wetlands ponds will intercept any eroded soils prior to
reaching Bear Canyon Creek or Boulder Creek.

3 0 ENGINEERING METHODS

3,1 Hydrologic Analvses

Previously accepted hydrologic analyses were used as the
basis for this study. For Skunk Creek, the hydrology was

Love & Associates. Inc.