PROJ00382

• Contract/PO #: C153685
• Contractor Name: Monument, Town of
• Contract Type: Loan
• Water District: 10
• County: El Paso
• Bill Number: SB 94-029
• Loan Projects - Doc Type: Feasibility Study

10

.-
BCJ'r'LE.'f

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

Chapter III . Background Information

the beached area. Some erosion gullies, about I to 2 feet deep, were observed on the slope near

the dam crest. The entire slope above the beached area was overgrown with vegetation, which

consists of thick brush, shrubs, and small to large pine trees. Our observations are consistent

with that reported in the 1997 SEa inspection report. Based on these observations, the

conditions of the upstream slope are considered to be poor.

The dam crest is uneven with numerous depressions and surface erosion gullies. No

surface protection materials such as gravels were observed. Over six deep erosion gullies, about

I to 2 feet deep, were observed on both downstream edge and upstream edge of the crest. As a

result of the erosion gullies, the crest widths vary significantly along the length of the crest.

Numerous medium to large pine trees are presently growing along the entire length of the dam

crest near both downstream and upstream edges of the crest. Our observations are consistent

with that reported in the 1997 SEa inspection report. Based on these observations, the

conditions of the dam crest are considered to be poor.

The downstream slope is uneven with numerous surface erosion gullies about I to 2 feet

deep. These gullies start from the top of the slo]Je and run along the entire length to the toe. The

entire slope is essentially overgrown with medium to very large pine trees and cottonwoods.

Some of the largest trees, with estimated diameters of 4 to 6 feet, had been cut down, but huge

stumps were still left on the dam. No evidence of slope instability of seepage, however, was

observed on the downstream slope. Our observqtions are consistent with that reported in the

1997 SEa inspection report. Based on these ob:,ervations, the conditions of the downstream

slope are considered to be poor.

The downstream toe and area downstream of the toe of the embankment were clear of

vegetation and well maintained. A chainlink fence along the entire toe of the embankment

appears to mark the property boundary. No evidence of any seepage was observed at the toe at

the time of our site inspection.

The spillway is located in the left abutment of the embankment. Bedrock is exposed in
the left abutment. The bedrock is thin-bedded weak cemented sandstone that is very soft and
friable. The bedrock on both sides of the spillway channel has been eroded significantly, as

Monument Lake Dam Feasibility Study