Tapps Lake Dike No 1 Reservoir Report

Last Updated: December 15, 2025

Tapps Lake Dike No 1, located in Pierce County, Washington, is a crucial structure designed for recreation purposes.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1911, this earth dam stands at a hydraulic height of 18 feet and a structural height of 9 feet, with a length spanning 280 feet. The dam holds a maximum storage capacity of 22,000 acre-feet and covers a surface area of 2570 acres, making it a significant water resource in the region.

Managed by the Washington Department of Ecology, Tapps Lake Dike No 1 is subject to state regulations, inspections, and enforcement to ensure its safety and functionality. With a satisfactory condition assessment as of February 2018, the dam poses a high hazard potential and requires regular inspections every 5 years. In case of emergencies, the dam does not have an Emergency Action Plan (EAP) prepared, highlighting the importance of proactive risk management measures for this critical infrastructure.

As part of the diversion from the White River, Tapps Lake Dike No 1 plays a vital role in water resource management in the area, supplying water for various recreational activities. With its historical significance and ongoing regulatory oversight, this dam serves as a key element in the regional water infrastructure, highlighting the intersection of water resources and climate resilience in the Pacific Northwest.

Year Completed

1911

Dam Length

280

River Or Stream

Diversion from White River

Primary Dam Type

Earth

Surface Area

2570

Hydraulic Height

18

Drainage Area

9.69

Nid Storage

22000

Structural Height

9

Hazard Potential

High

Foundations

Soil

Nid Height

18
       
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.