Twin Valley Lakes - East Dam

Twin Valley Lakes - East Dam is an earth dam located in Johnson County, Iowa, built in 1965. It carries a Significant hazard potential classification and has a poor condition assessment.

About Twin Valley Lakes - East Dam

Twin Valley Lakes - East Dam is a dam in Johnson, Iowa. The dam is owned by Lori Pike,twin Valley Lakes Association (private). It impounds the Tr- Iowa River near Coralville Reservoir.

The dam stands 50 feet tall and stretches 500 feet across, creates a reservoir covering 16 acres, has a maximum storage capacity of 392 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1965, the structure is well into its service life at over 50 years old.

This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. The most recent inspection on record was 10/24/2022.

At 50 feet, this dam is taller than 93% of dams nationwide.

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Significant HazardPoor ConditionEmergency Action Plan: Not Required

Location

StateIowa
CountyJohnson
Nearest CityCoralville Reservoir
River/StreamTr- Iowa River
Coordinates41.81250, -91.62200

Physical Characteristics

Dam TypeEarth
NID Height50 ft
Dam Height50 ft
Dam Length500 ft
Year Completed1965 (61 years old)

Storage & Hydraulics

NID Storage392 acre-ft
Max Storage392 acre-ft
Normal Storage192 acre-ft
Surface Area16 acres
Drainage Area0 sq mi
Spillway TypeNone

Ownership & Safety

OwnerLori Pike,Twin Valley Lakes Association
Owner TypePrivate
Hazard ClassificationSignificant
Condition AssessmentPoor
Last Inspection10/24/2022
Emergency Action PlanNot Required

Identifiers

NID IDIA03528
Federal IDIA03528
More InfoState Dam Safety Program

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