FLOOD10854 ‎(2)‎

• Designation Number: 590
• County: Denver
• Community: Denver
• Title: FIS - Denver - Volume 1
• Date: 11/17/2005
• Prepared For: Denver
• Prepared By: FEMA
• Floodplain - Doc Type: Current FEMA Regulatory Floodplain Information

approximately 0.5 mile from the South Platte River. Floodwater, searching out a
route to the river, flowed down South Broadway, an important neighborhood
business street (Reference 13). The Harvard Gulch Flood Control Project, completed
in 1966, was designed for the 10-percent-alUlual-chance flood and has alleviated
these problems. The largest flood event since the completion of this project occurred
on June 8, 1969. Three gages in this basin recorded between 1.2 inches and
2.6 inches of rainfall in a I-hour period. The runoff hydrograph for this event was
recorded at the gaging station near South Logan Street. The hydrograph peak was .'~
approximately 1,600 cfs, and this flow was confined within the drainage
improvements (Reference 14).

For Goldsmith Gulch and Southmoor Park Tributary, little information is available
on past flooding because development was sparse in these areas. Flooding indicative
of what might be expected under present conditions occurred on May 5 and 6, 1973,
when the capacities of the crossings at Dartmouth and Y ale Avenues were exceeded
by what was estimated to be a 5- to 10-year event (References 15 and 16).

Major floods have not occurred on Sanderson Gulch in the last 20 years and prior to
that time there are no accurate records available (References 17 and 18).

For Weir Gulch, First Avenue Tributary, and Dakota Avenue Tributary, historical
information on flooding is scarce. A few instances of flooding resulting in minor
basement damage and some channel and bridge damage have been reported
(References 19 and 20).

There were major floods on Sand Creek in 1896, 1912, 1917, 1921, 1933, 1938,
1948, 1957, and 1965. Because the basin was essentially undeveloped up to
approximately 1940, flood damages are not well documented. The 1948 flood had a
discharge at the mouth estimated at 10,500 cfs. Resulting damages throughout the
basin were over $130,000. Near Stapleton International Airport the 1957 flood had a
discharge estimated to be 25,000 efs. Total damages throughout the basin were in
excess of $330,000. The 1965 flood resulted in damages of $2,517,000 along
Sand Creek. The discharge below Toll Gate Creek (located upstream in the City of
Aurora) was 18,900 cfs (Reference 21).

Little definitive data on past flooding on First Creek and First Creek Tributary are
available due to the sparse development in the area. Until recently, the First Creek
and First Creek Tributary floodplains were entirely agricultural.

No specific information regarding historic flood magnitudes or extent of flooding and
damages is available for Coon Creek, Lakewood Gulch, West Harvard Gulch, and
Dry Gulch (Harvard Gulch Tributary).

2.4 Flood Protection Measures

There are numerous dams, reservoirs, and channel improvements within the
South Platte River Basin. Many of these flood protection measures affect flood
peaks on the flooding sources that flow through Denver.

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