FLOOD07446

• Designation Number: 288
• County: Douglas
• Community: Parker
• Basin: South Platte
• Title: Flood Insurance Study - Parker, Douglas County, Colorado
• Date: 9/1/1987
• Designation Date: 12/1/1987
• Floodplain - Doc Type: Floodplain Report/Masterplan

gaging station at Melvin recorded a peak discharge of 10,700 cfs.
Total damages were estimated at $200,000.

A severe storm centered over the Bayou Gulch basin, a tributary to
Cherry Creek, during the afternoon of July 28, 1922. Heavy
rainfall was reported in the area bounded by lines 3 miles north of
Parker, approximately 4 miles west of, Cherry Creek, 1 mile south of
Franktown, and by the Douglas C~unty limits on the east.
Unofficial rainfall amounts varied from 1 to 3.5 inches and
occurred in approximately 2 hours. An estimatred peak discharge of
8,700 cfs flowed out of Bayou Gulch. The discharge on Cherry
Creek, 3 miles north of Parker, was estimated to be 17,000 cfs.
Although no damage occurred in Denver, this was considered a major
flood for the upstream part of the basin.

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Peak discharges along Cherry Creek were 1,000 cfs up8tream from
Franktown; 39,900 cfs near Melvin; alld 58,000 cfs at Cherry Creek
Dam. An estimated peak discharge of, 14,100 cfs flowed from Piney
Creek, a right-bank tributary of Cherry Creek. During the evening
and night of June 16, the Cherry Creek reservoir impounded a flood
that had a volume of 16,000 acre-fee~. Three of the 18 small dams
constructed by the SCS in the upper Cherry Creek basin between
Franktown and Parker were filled. 'rwo of these were subsequently
overtopped and sustained erosion damage. The remaining structures
were outside the area of high-intensity rainfall and received only
moderate runoff. The heavy runoff c~used major flooding along the
main stem of Cherry Creek from the' vicini ty of Franktown to the
Cherry Creek reservoir. Approximately 2,720 acreas were flooded.
Most of the bridges across Cherry Creek were either damaged or
destroyed. One life was lost during the flood on Cherry Creek.
Flood damages totaled approximately $1.3 million.

No floods of consequence have occurred since 1965.

2.4 Flood Protection Measures

The possibility of future flood damlilge in the upper Cherry Creek
areas has been somewhat reduced by the construction of 32 flood-
water-retarding structures. The SCS completed construction of
these structures in 1965 as part of an overall plan (Reference 4).
These structures were designed for an agricultural community with
design floods having a 25-year recurrence interval.

3.0 ENGINEERING METHODS

For the flOOding sources studied in detail in the community, standard
hydrologic and hydraulic study methods were used to determine the flood
hazard data required for this study. Flood events of a magnitude which
are expected to be equaled or exceeded Once on the average during any
10-, 50-, 100-, or 500-year period (recurrence interval) have been
selected as having special significance !for floodplain management and
for flood insurance rates. These events, ;commonly termed the 10-, 50-,
100-, llnd 500-year Hoods, have a 10-, 2-, 1- and 0.2-percent chance,

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