Stillwater

Stillwater is a concrete dam located in Penobscot County, Maine, built in 1902. It carries a Low hazard potential classification and has a satisfactory condition assessment.

About Stillwater

The primary purpose of Stillwater 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 Black Bear Hydro Partners, Llc, Black Bear Development Holdings, Llc & Black Bear So, Llc (private). It impounds the Stillwater River near Orono.

The dam stands 25 feet tall and stretches 1,720 feet across, creates a reservoir covering 191 acres, has a maximum storage capacity of 1,910 acre-feet, and collects water from a drainage area of 7,602 square miles. Completed in 1902, the structure is over a century 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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 09/14/2022.

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

Low HazardSatisfactory ConditionEmergency Action Plan: Not Required

Location

StateMaine
CountyPenobscot
Nearest CityOrono
River/StreamStillwater River
Coordinates44.90953, -68.68305

Physical Characteristics

Dam TypeConcrete
NID Height25 ft
Dam Height25 ft
Dam Length1,720 ft
Year Completed1902 (124 years old)

Storage & Hydraulics

NID Storage1,910 acre-ft
Max Storage1,910 acre-ft
Normal Storage1,910 acre-ft
Surface Area191 acres
Drainage Area7,602 sq mi
Max Discharge25,000 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeHydroelectric
OwnerBlack Bear Hydro Partners, LLC, Black Bear Development Holdings, LLC & Black Bear SO, LLC
Owner TypePrivate
Hazard ClassificationLow
Condition AssessmentSatisfactory
Last Inspection09/14/2022
Emergency Action PlanNot Required

Identifiers

NID IDME00139
Federal IDME00139
More InfoState Dam Safety Program

Nearby Dams