Stillwater Reservoir

Stillwater Reservoir is a concrete dam located in Providence County, Rhode Island, built in 1918. It carries a High hazard potential classification and has a fair condition assessment.

About Stillwater Reservoir

The primary purpose of Stillwater Reservoir is fish and wildlife pond. The dam creates habitat for fish and wildlife, supporting local ecosystems and potentially serving conservation goals. The dam is owned by Ri Dem Fish & Wildlife (state). It impounds the Woonasquatucket River near Smithfield.

The dam stands 39 feet tall and stretches 670 feet across, creates a reservoir covering 240 acres, has a maximum storage capacity of 3,900 acre-feet, and collects water from a drainage area of 26 square miles. Completed in 1918, 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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam.

At 39 feet, this dam is taller than 86% of dams nationwide.

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 Rhode Island 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 HazardFair ConditionEmergency Action Plan: Yes

Location

StateRhode Island
CountyProvidence
Nearest CitySmithfield
River/StreamWoonasquatucket River
Coordinates41.90892, -71.54209

Physical Characteristics

Dam TypeConcrete
NID Height39 ft
Dam Height20 ft
Dam Length670 ft
Year Completed1918 (108 years old)

Storage & Hydraulics

NID Storage3,900 acre-ft
Max Storage3,900 acre-ft
Normal Storage2,400 acre-ft
Surface Area240 acres
Drainage Area26 sq mi
Max Discharge1,800 cfs

Ownership & Safety

PurposeFish and Wildlife Pond
OwnerRI DEM FISH & WILDLIFE
Owner TypeState
Hazard ClassificationHigh
Condition AssessmentFair
Emergency Action PlanYes

Identifiers

NID IDRI03101
Federal IDRI03101
More InfoState Dam Safety Program

Nearby Dams