Van Stone Pit Lake Dam Reservoir Report

Last Updated: January 12, 2026

Van Stone Pit Lake Dam in Washington, completed in 1999, serves as a critical structure for managing tailings from surrounding operations.


°F

°F

mph

Wind

%

Humidity

Summary

This private dam, regulated by the Washington Department of Ecology, stands at a height of 25 feet with a capacity for storing 448 acre-feet of water. Located on Onion Creek in Stevens County, the dam has a drainage area of 0.06 square miles and a maximum discharge capacity of 86 cubic feet per second.

Despite its vital role in water resource management, Van Stone Pit Lake Dam poses a high hazard potential due to its poor condition assessment as of September 2021. The dam's inspection frequency is set at every 5 years, with the most recent assessment indicating a need for improvement. With a history of modifications unlisted, the dam's structural integrity and emergency preparedness could be points of concern for water resource and climate enthusiasts. As the dam's risk management measures and emergency action plan status remain undisclosed, further attention and oversight may be warranted to ensure the dam's safe operation and maintenance.

Year Completed

1999

Dam Length

100

River Or Stream

Onion Creek

Primary Dam Type

Earth

Hydraulic Height

25

Drainage Area

0.06

Nid Storage

448

Structural Height

25

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

25
       
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.