Evans No.1 is an earth dam located in Custer County, South Dakota, built in 1951. It carries a Low hazard potential classification.

Hazard potentialLowFailure would cause limited damage
ConditionNot assessed
Emergency action planNot reported
Last inspectionNot reported
Height21 ft
Built195175 years ago

Dam profile

NID height · 21 ft
21 FT TWO-STORY HOUSEMEDIAN U.S. DAM · 24 FT

21 ft tall and 555 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.

About Evans No.1

The primary purpose of Evans No.1 is fire protection, stock, or small fish pond. The dam maintains a small impoundment used for fire suppression, livestock watering, or as a fish pond. The dam is owned by John T. Colgan (private). It impounds the Tr-cheyenne.

The dam stands 21 feet tall and stretches 555 feet across, and has a maximum storage capacity of 50 acre-feet. Completed in 1951, the structure is well into its service life at over 50 years old.

This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life.

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Location

StateSouth Dakota
CountyCuster
Nearest CityNone
River/StreamTr-cheyenne
Coordinates43.83833, -103.03166

Physical Characteristics

Dam TypeEarth
NID Height21 ft
Dam Height21 ft
Dam Length555 ft
Year Completed1951 (75 years old)

Storage & Hydraulics

NID Storage50 acre-ft
Max Storage50 acre-ft
Normal Storage20 acre-ft
Max Discharge1,080 cfs

Ownership & Safety

PurposeFire Protection, Stock, Or Small Fish Pond
OwnerJohn T. Colgan
Owner TypePrivate
Hazard ClassificationLow
Condition AssessmentNot assessed
Emergency Action PlanNot Required

Identifiers

NID IDSD01369
Federal IDSD01369
More InfoState Dam Safety Program