Lower South Platte River Study

• Contractor Name: Colorado Water Conservation Board
• Loan Projects - Doc Type: Feasibility Study

Lower South Platte River Study
Colorado Water Conservation Board
' December 2001
The property is privately owned. A road would need to be relocated and an existing
' ranch would be impacted by construction of the reservoir. No wetland areas have
been identified by the USFWS on their wetlands delineation mapping at the
reservoir site. However, field reconnaissance indicates that wetlands occur in
' riparian areas along the Ramsey Draw. The reservoir could be filled by gravity from
the North Sterling Outlet Canal or by pumping from the Harmony Ditch. The
' contributing drainage area to the site is 7.6 square miles. The reservoir would have a
capacity of 2,900 acre-feet and a maximum normal pool at Elevation 3840. The dam
would be a zoned embankment dam with a height of 50 feet and a crest length of
' 2,100 feet. The reservoir would cost a total of$4,930,000, or$1,700 per acre-foot of
storage.
Corral Creek A
' The Corral Creek A Reservoir site is located about 39 miles upstream of the state
line along the Lower South Platte River, 7.3 miles northwest of Crook, Colorado.
The dam site is in a broad valley with gentle slopes. Corral Creek, which may be a
' perennial stream, runs through the valley and some wetland areas have been
identified on USFWS mapping. The land on which the dam and reservoir would be
constructed is privately owned. Numerous prairie dog burrows were observed at the
site. The reservoir would have a capacity of 9,000 acre-feet with a maximum normal
pool at Elevation 3950. The dam would be a zoned embankment with a height of 70
' feet and a crest length of 4,700 feet. The North Sterling Outlet Canal could be used
to fill the reservoir by gravity. Pumping from the Harmony Ditch also could be used
to fill the reservoir. The contributing Corral Creek drainage area to the site is 9.9
' square miles. The total cost for the construction of the dam would be $10,840,000,
or$1,200 per acre-foot of storage.
' Corral Creek B
' The Corral Creek B Reservoir site is located 6.5 miles west of Crook, Colorado,
approximately 39 miles upstream of the state line along the Lower South Platte
River. The site has medium to gentle sloping abutments with occasional outcrops of
' slightly cement siltstone. The depth to bedrock at the dam is uncertain. The land at
this site is privately owned with a well on site, but no roads or buildings would need
to be relocated for the construction of the reservoir. Corral Creek runs directly
' through the site, and wetlands are also located on the site according to the USFWS
wetland delineation maps. The reservoir could be filled from the North Sterling
' Outlet Canal or by pumping water from the Harmony Ditch. The contributing
drainage area to the reservoir site is 11.5 square miles. The reservoir would have a
capacity of 2,500 acre-feet with a maximum normal pool at Elevation 3860. The
' dam would be a zoned embankment with a height of 50 feet and crest length of
GEI Consultants, Inc. 4-16 01002 Dec 2001 Lower South Platte River Study