Three Rivers

Three Rivers is a gravity dam located in St. Joseph County, Michigan, built in 1917. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Three Rivers

The primary purpose of Three Rivers is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Grande Pointe Power (private). It impounds the St Joseph River near Three Rivers.

The dam stands 16 feet tall and stretches 1,321 feet across, creates a reservoir covering 601 acres, has a maximum storage capacity of 902 acre-feet, and collects water from a drainage area of 985 square miles. Completed in 1917, the structure is over a century old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 08/30/2022.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Michigan dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateMichigan
CountySt. Joseph
Nearest CityThree Rivers
River/StreamSt Joseph River
Coordinates41.94090, -85.62500

Physical Characteristics

Dam TypeGravity
NID Height16 ft
Dam Height16 ft
Dam Length1321.5 ft
Year Completed1917 (109 years old)

Storage & Hydraulics

NID Storage902 acre-ft
Max Storage902 acre-ft
Normal Storage902 acre-ft
Surface Area601 acres
Drainage Area985 sq mi
Max Discharge22,500 cfs

Ownership & Safety

PurposeHydroelectric
OwnerGrande Pointe Power
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection08/30/2022
Emergency Action PlanYes

Identifiers

NID IDMI00395
Federal IDMI00395
More InfoState Dam Safety Program

Nearby Dams