Sullivan Lake Reservoir Report

Last Updated: December 12, 2025

Sullivan Lake, located in Metaline Falls, Washington, is a picturesque body of water created by a gravity dam completed in 1923 for hydroelectric purposes.


°F

°F

mph

Wind

%

Humidity

Summary

With a height of 25 feet and a hydraulic height of 29 feet, the dam stands at 34 feet tall and spans 210 feet in length. The reservoir boasts a normal storage capacity of 31,000 acre-feet, offering ample water resources for both power generation and recreational activities.

Managed by the Federal Energy Regulatory Commission, Sullivan Lake Dam has a controlled spillway and nine slide (sluice gate) outlet gates to regulate water flow and ensure safety. The dam's hazard potential is classified as high, with a very high risk assessment score of 1. Despite its age, the condition assessment of the dam is currently listed as "Not Available," indicating a need for further evaluation and maintenance to ensure its continued safety and functionality.

Water resource and climate enthusiasts will appreciate Sullivan Lake's unique blend of historical significance, hydroelectric power generation, and recreational opportunities. As a vital part of the Pend Oreille River system and surrounded by the natural beauty of the Washington wilderness, Sullivan Lake serves as a reminder of the importance of responsible water management and environmental stewardship in the face of a changing climate.

Year Completed

1923

Dam Length

210

Dam Height

25

River Or Stream

Sullivan Creek, Pend Oreille R

Primary Dam Type

Gravity

Surface Area

1923

Hydraulic Height

29

Drainage Area

51

Nid Storage

31000

Structural Height

34

Outlet Gates

Slide (sluice gate) - 9

Hazard Potential

High

Nid Height

34
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.