C153607L Bylaws and Adendums

• Contract/PO #: C153607L
• Contractor Name: Trinchera Irrigation Company
• Contract Type: Loan
• Water District: 35
• County: Costilla
• Bill Number: SB 92-87
• Loan Projects - Doc Type: Contract Documents

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INTRODUGTION

The Mountain Home Reservoir Is located approximately 3,6 miles southeast
of Fort Garland, Colorado along Trlnchera Greek. The dam site Is located In the
southwest 1/4 of Section 36, Township 36 South, Range 72 West, Costilla County,
Colorado. The reservoir Is Impounded by a main dam and a saddle dam which
were constructed In 1908, The main dam has a structural height of 163 feet and
a hydraulic height of 126 feet, The reservoir has a capacity of 18.600 acre-feet
at the spillway, crest. The emergency spillway Is located along the right abut-
ment and Is approximately 10 feet below the crest of the dam,

,Trlnchera ,Irrigation Company has proposed a rehabllltatlon of the reservoir
dam and appurtenant structures to allow maximum water storage capacity to be
utilized. . At the present time the structure Is under a hold order by the State
, "Engineer's Office from a maximum Gage Height of 100.0 feet to, Gage Height 87,6
feet.

The general purpose of the proposed feasibility study Is to determine the
rehabilitation necessary and set a course to return the reservoir back to Its. full
storage capacity In the most economical manner,

STATEMENT OF PROBLEM

There are various problems associated with Mountain Home Reservoir that
are of concern. A list of the more pertinent problems Is as follows:

1. Inadequate spillway to safely pass 76% of PMP,
2. Inadequate freeboard In conjunction with the design flood,
3. Seepage In the abutment area when the reservoir Is at full pool.
4. Structural Integrity of the dam at full pool.
6. Spillway channel Integrity at high flows,
. 6. Downstream damage at high spillway flows.
7 ~ " Stability of geologic formations In the spillway area.

The primary problem associated with the Mountain Home Reservoir is the
Inadequate spillway. The other problems noted are a direct result of or are
associated with the spillway. Thus the main focus of the feaslbll1ty study will
be the siZing of and design of alternative spillways to address the problems
noted.

SOLUTION TO THE PROBLEM

At this point in time it Is known that several problems exist at Mountain
Home Reservoir and Its associated structures, The question at hand Is how best
to maintain the reservoir for the present and future at a cost that Is feasible
for the value of the water being stored. What value the reservoir has and
whether the value of the water to be stored in the reservoir justlfles the cost to
maintain It Is the question that must be answered,

Toward that goal, SMITH GEOTECHNICAL proposes to provide a Feaslbll1ty

Mountain Home Reservoir Proposal
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