FLOOD04416

• Designation Number: 304
• County: Adams
• Community: Unincorporated Adams County
• Stream Name: Big Dry Creek, (ADCO), North area tributaries
• Basin: South Platte
• Title: Flood Hazard Area Delineation - Big Dry Creek, ADCO, North Area Tributaries
• Date: 7/1/1989
• Designation Date: 1/1/1990
• Floodplain - Doc Type: Floodplain Report/Masterplan

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Elms Run
This tributary is the shOJ1est tributary included in this study. The
drainage area is 0.3 square miles and the main channel length is 0.5
miles. Channel slopes are between 2 and 4 percent. The channel typi-
cally lies in swale areas between rolling pasture.

Interstate 25, the Equily Ditch, and Ihe Bull Canal intersect Shay
Ditch. The Equity Ditch is localed in the headwater area of the water~
shed while the Bull Canal crosses the stream lower In the basin. Inad-
vertent detention upstream from the (-25 crossing is approximately 150
AF.

The UPRR and German Ditch cross Elms Run within a short distance of one
another in the upper part of the basin.

Morris Creek
Morris Creek is the northernmost of the five right bank tributaries.
It drains an area of approximately 1.0 square mile and has a main
channel length of 1.8 miles. Channel slopes are typically 1.0 to 2.0
percent. Like the Wadley tributaries in the south, much of the drain-
age area is cultivated; thus the channel is poorly defined along most
of its length upstream from l60th Avenue.

Mustang Run
Mustang Run drains an area of 1.5 square miles and has a channel length
of 3.0 miles. The stream flows in a southeasterly direction at a slope
of approximately 1.5 to 2 percent. The stream channel is identified by
the swales between areas of pasture and cultivated fields in the area
to the east of 1-25 and by more defined ditches in the Mustang Estates
(low-density residential subdivision) area 10 the west of Huron Avenue.

The UPRR crosses Morris Creek in the lower part of the basin. The
railroad embankment diverts stormwater runoff along 160th Avenue where
the UPRR is elevated over 160th Avenue.

The Bull Canal and 1-25 cross Mustang Run within a short distance of
one another near the mid-point of the watershed. Inadvertent detention
is significant upstream from the 1-25 crossing with approximately 45 AF
of storage.

Shay Ditch
Shay Ditch is Ihe most southern of the four mam tributary streams
which enter Big Dry Creek from the west. It is also the second largest
of the watersheds in this study with a drainage area of 1.8 square
miles. The channel slopes for the lower reaches of Shay Ditch are
about 1.2 percent while the uppermost reach is 2.0 percent. The over-
all length of the main channel is 2.8 miles. To the east of Interstate
25 (1-25), much of the basin is cultivated and the stream channel is
poorly defined. To the west of 1-25, however, the main stream channel
lies in swales between areas of pasture and cultivated fields.

Sack Creek
The majority of the Sack Creek drainage area of 1.4 square miles lies
between 1-25 and Big Dry Creek. The channel is approximately 2.6 miles
long with a slope of 1.5 to 2 percent. The majority of this area is
cultivated at present and the stream channel is poorly defined.

The Bull Canal and 1-25 cross Sack Creek in the headwater area.

South Fork Preble Creek
The total watershed area for South Fork Preble Creek is 1.2 square
miles. The stream length IS 2.4 miles with a typical channel slope of
1.2 percent. Much of the stream valley east of Washington Street is
backwater wetland area. To the west, the channel is poorly defined in
cultivated areas but identifiable in swales.

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