FLOOD04689

• County: Statewide
• Basin: Statewide
• Title: 2001 Colorado Flood Documentation Report: Table of Contents and Sections 1 - 8
• Date: 3/1/2002
• Prepared For: CWCB
• Prepared By: URS
• Floodplain - Doc Type: Flood Documentation Report

ExICUUVI SumOlaIV

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The following is a short summary of the flooding that occurred in 2001 for the specific areas
within the State of Colorado.

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Colorado Springs

. A localized rainstorm and significant flooding were reported for August 31, 2001,

. A NOAA Event Record indicates that more than 5 inches fell in approximately 5 hours,
equivalent to a greater than tOO-year event locally, The storm was very localized around the
downtown area.

. Flow data for Monument Creek and Fountain Creek for September 181 indicated little impact from
the storm.

. As the storm was very localized, only a small area near downtown was affected, and no creeks
were reported to have overtopped their banks.

. The primary cause of flooding was associated with lightning, which caused a lift station failure.
With the pumps out and a heavy local rainfall, two to three feet of water inundated Interstate 25,
which was dosed for at least seven hours,

. Damage to the pumps and other electrical equipment cost COOT approximately $30,000,
COOT estimated cleanup costs at approximately $2,000,

. A drop structure construction project in Monument Creek was damaged during the event,
costing the City approximately $30,000,

. No private property damage was reported.

Greeley

. A large localized rainstonn was reported for July 131\ 2001 for the Greeley area,

. Research indicated very significant flooding and property damage from this storm, Three-
foot deep water was reported in some areas of Greeley, including downtown areas,

. The National Climatic Data Center indicates that from 3 to 5 inches of rainfall fell in less
than Z hours on July 131h, This event is equivalent to at least a tOO-year frequency event
locally.

. Damages and impacts included several flooded basements (among them City Hall), stranded
motorists due to inundated streets, and an electrical outage for approximately 2,300 residents,
A NOAA Event Record listed an estimated total of $600,000 in property damages.
Damage at City Hall was estimated to be approximately $250,000,

Holyoke

. A stonn was reported for September 7, 2001 for the Holyoke area.

. Preliminary data from NOAA indicates that 0.57 inches of precipitation fell in less than
. one hour - less than a 2-year frequency event.

URS

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