FLOOD10727

• County: Weld
• Community: Dacono
• Title: FIS - Dacono
• Date: 1/1/1979
• Prepared For: Dacono
• Prepared By: FEMA
• Floodplain - Doc Type: Current FEMA Regulatory Floodplain Information

No streamflow gaging information is available for the major drainage-
way flowing through Dacono. Gaging information on small watersheds
in Colorado is currently being collected by the State Highway
Department, but records to date are sporadic and the period of
record is short. The U.S. Soil Conservation Service method for
developing synthetic hydrographs was, therefore, used to determine
frequency discharges in this basin (Reference 6). This method is
particularly suited to small agricultural watersheds. Rainfall
data used in the hydrologic analyses were obtained from the National
Oceanic and Atmospheric Administration Atlas for Colorado (Reference
7), and soil and land use information was taken from maps prepared
by the u.s. Soil Conservation Service (Reference 3).

Peak discharge-drainage area relationships for the Tri-Area Drainage-
way are shown in Table 1.

Table 1. Summary of Discharges

Flooding Source
and Location

Drainage Area
(Square Miles)

Peak Discharges
(Cubic Feet per Second)
IO-Year 50-Year IDO-Year SOD-Year

Tri-Area Drainageway
At Downstream Study
Limit
At 7th street

1.4
0.8

310
160

580
310

740
390

1180
620

3.2 Hydraulic Analyses

Analyses of the hydraulic characteristics of streams in the commu-
nity were carried out to provide estimates of the elevations of
floods of the selected recurrence intervals along each stream
studied in the community.

Cross section data for the Town of Dacono were obtained from field
surveys by Gingery Associates,' Inc., in October 1977. Culverts
were measured to obtain stuctural geometry.

A summary of cross section locations and elevations for the Town
of Dacono are shown in Table 2.

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