WSP07855

• File Number: 8200.765
• Description: Little Snake River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 8/23/1990
• Author: Western Water Consul
• Title: Draft Appraisal of P and M Conditional Water Rights for Three Forks Reservoir Project - Little Snake River Basin
• Water Supply Pro - Doc Type: Report/Study

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

0.- ".,.\ I
:Ju:':_'1

P & M holds two separate rights for the Three Forks ReselVoir which is located on the

Wyoming-Colorado state line. The Colorado decrees for Three Forks and Sheep Mountain

ReselVoirs, dated June 5, 1972, each call for 75,000 AF of storage. The Wyoming permit

for Three Forks ReselVoir, dated June 20, 1972, is for a dam at the same location as the

Colorado Three Forks ReselVoir decree except with a storage amount of 22,865 AF.

According to P & M, their future plans are to develop a single large dam on the

Little Snake River with a total capacity of 172,865 AF at the common site of its Wyoming

Three Forks Permit and Colorado Three Forks Decree to embody the full entitlement of

these rights as well as the Sheep Mountain ReselVoir Decree water. Therefore, the July

31,1990 study evaluated the impacts of a consolidated Three Forks ReselVoir with 172,685

AF of storage. P & M holds no direct flow diversion rights under this project.

Modeled project demands included storage water diversions for industrial uses. It

was assumed that the industrial water would be diverted directly from the reselVoir area

and 100 percent consumed with no return flows. To quantify realistic industrial demands

that the reselVoir could meet on a year to year basis, WWC performed a firm yield

evaluation using the WIRSOS model.

Bypass flow requirements for instream flow considerations were included in the

WIRSOS modeling. An instream flow requirement of 100 cfs has been suggested for the

Little Snake River below Savery Creek by the Wyoming Game and Fish Department. Of

this 100 cfs, it was assumed that 24 cfs would come from Savery Creek and Sandstone

ReselVoir storage releases as modeled in the Sandstone Depletion Study (SWEC, 1987),

4