PROJ02106

• Contract/PO #: FS0063FX
• Contractor Name: Groundwater Appropriators of the South Platte
• Contract Type: Miscellaneous
• Water District: 0
• Loan Projects - Doc Type: Feasibility Study

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fill the reservoir. The information and assumptions that were used to estimate the quantity of
water, which was available for diversion, are as follows:

· Average daily stream gage records were obtained for the USGS Julesburg gage
station for the period of 1966-1996.
· Criteria for when diversions would be allowed were based on meeting the
requirements ofthe Colorado-Nebraska compact and respecting the Colorado prior
appropriation doctrine.

The USGS gage records were recorded as average daily flows at the Julesburg gage. Flows in
the river during the winter months were assumed to be available for storage. In addition, flows
during the compact time period were assumed available for diversion if the Julesberg gage was
above the 120 cfs minimum. Flows during this time period would be diverted under a refill right
for the reservoir. There were no detailed investigations done to determine ifthese excess flows
during the compact time period would actually be available at the point of diversion for the
project facilities. The study results did conclude that there are adequate supplies available for
diversion during the winter months.

The daily gage flows were averaged on a monthly basis to calculate an average flow for the
month. The conclusions show there is a minimum of 94,000 acre-feet of water that could be re-
regulated on a long-term annual average. Based on the demands necessary to satisfy the
proposed reservoir configurations with fill and refill rights, there is an adequate water supply in
the river for this project.

The calculated water available for diversion was considered to be 100% deliverable to the
reservoir. This assumption was made based on a conversation with the operator of the Peterson
Ditch. The operator indicated that the Peterson Ditch diversion structure was capable of
diverting all flow from the South Platte River and that the Peterson Ditch was a gaining reach
from the river to the proposed reservoir site. There would be some ditch seepage losses, which
are beyond the scope of this project. It was assumed that these losses were minor and would not
significantly affect the conclusions of this study.

E. Permitting Considerations
The proposed project will require several permits to allow construction to begin. These include
local, State and Federal permits. The most significant of the permits necessary for this project is
the Clean Water Act permit called a 404 permit for activities associated with wetlands. The
State of Colorado will consider this a jurisdictional dam. This will require approval of
construction plans and documents by the dam safety branch ofthe State Engineer. Other minor
permits associated with the project will include a fugitive dust permit for air quality, an NPDES
permit for any construction dewatering activities and a stormwater management plan.

The 404 permit is the most critical permit to obtain for this project. The requirements of the
Clean Water Act allow for review by the Corps of Engineers, which is in charge of issuing these
permits. The U.S. Fish and Wildlife Service and the EPA have the opportunity to make
comments and review permit applications and make recommendations to the Corps of Engineers.

A critical part of the review process is based on what is called 404 (b) 1 guidelines. This part of
the law requires an extensive alternatives analysis that look at other potential locations, different
configurations ofthe project as well as a "no project" alternative. A persuasive argument has to

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