PROJ00396

• Contract/PO #: C153741
• Contractor Name: Vouga Reservoir Association
• Contract Type: Loan
• Water District: 72
• County: Saguache
• Bill Number: SB 94-029
• Loan Projects - Doc Type: Feasibility Study

I
,
I
I
I
I'
I
1
I,
I
I
I
I
I
I
I
I
I
J

1.0
INTRODUCTION

1.1 PROJECT DESCRIPTION

V ouga Dam and Reservoir is located in Saguache County approximately 10 miles from
Doyleville, Colorado. The dam and reservoir is owned and operated by the Vouga Reservoir
Association (VRA). The reservoir is located on Razor Creek a tributary to Tomichi Creek and
has a drainage area of approximately 37.2 square miles at the dam. A general site map is shown
on Figure I-I. The Labrouche property surrounds the V ouga Reservoir and is outlined in black
dotted line on the location map.

Vouga Dam is a zoned earthfill embankment with a crest elevation of 9,600 feet NGVD and
crest length of 1,200 feet and an existing height of 56 feet. The embankment was constructed in
two stages. The first stage, storing 510 acre-feet, was built in 1955 and consisted ofa 50-foot-
high embankment with outlet conduit and emergency spillway. The second stage, built in
1978, included a lO-foot embankment and spillway raise and an outlet conduit extension.
Reservoir storage is now 920 acre-feet at the emergency spillway invert (6 feet below existing
dam crest). Controlled releases from the reservoir occur through a gated, low-level intake and a
corrugated metal pipe (CMP) outlet conduit located near mid-valley. Uncontrolled releases
pass through a 40-foot-wide open channel emergency spillway on the left abutment.

The emergency spillway channel is a cut and fill structure constructed of native soil and rock
materials. This structure has suffered a number of washouts resulting in erosion of the hillside
and deposition of debris fans on fields located downstream. Review of the Colorado Division
of Water Resources (CDWR) inspection record indicates washouts in 1979 and 1987. Vouga
Dam and Reservoir has been designated an intermediate Class II structure, requiring a spillway
capable of passing the outflow from a design storm equal to 50 percent of probable maximum
precipitation (pMP). Currently, CDWR has a moratorium on requiring spillway modifications
for dams above 7,500 feet due to lack of reliable PMP estimates in Colorado.

24216IRLOOC 02.12.97(3,08PM)/RPT

1-1