Lewis Dam is an earth dam located in Pennington County, South Dakota, built in 1961. It carries a Low hazard potential classification.

Hazard potentialLowFailure would cause limited damage
ConditionNot assessed
Emergency action planNot reported
Last inspectionNot reported
Height20 ft
Built196165 years ago

Dam profile

NID height · 20 ft
20 FT TWO-STORY HOUSEMEDIAN U.S. DAM · 24 FT

20 ft tall and 405 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 Lewis Dam

The primary purpose of Lewis Dam 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 Fred Lewis (private). It impounds the Tr-cheyenne.

The dam stands 20 feet tall and stretches 405 feet across, and has a maximum storage capacity of 60 acre-feet. Completed in 1961, 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
CountyPennington
Nearest CityNone
River/StreamTr-cheyenne
Coordinates44.26166, -102.17832

Physical Characteristics

Dam TypeEarth
NID Height20 ft
Dam Height20 ft
Dam Length405 ft
Year Completed1961 (65 years old)

Storage & Hydraulics

NID Storage60 acre-ft
Max Storage60 acre-ft
Normal Storage42 acre-ft
Max Discharge1,125 cfs

Ownership & Safety

PurposeFire Protection, Stock, Or Small Fish Pond
OwnerFred Lewis
Owner TypePrivate
Hazard ClassificationLow
Condition AssessmentNot assessed
Emergency Action PlanNot Required

Identifiers

NID IDSD01981
Federal IDSD01981
More InfoState Dam Safety Program