Sea Horse Ranch Dike Reservoir Report
Nearby: West Fork Dam Failor Lake Dam
Last Updated: December 15, 2025
Sea Horse Ranch Dike, located in Grays Harbor, Washington, is a private structure designed to protect the surrounding area from flooding.
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Summary
Completed in 1961, this Earth-type dam stands at a height of 15 feet and stretches 165 feet in length. With a storage capacity of 75 acre-feet, the dike plays a crucial role in managing water resources along Tr-Gillis Slough, with a drainage area of 0.3 square miles.
Managed by the Washington Department of Ecology, Sea Horse Ranch Dike is regulated, inspected, and enforced by the state to ensure its structural integrity and safety. Despite its low hazard potential, the dam has not been rated for its condition assessment, indicating a need for further evaluation. With a primary purpose categorized as "Other," the dike serves as a vital component in the region's water resource infrastructure, showcasing the importance of private entities in managing water-related challenges.
Located in Congressional District 06, Washington, Sea Horse Ranch Dike stands as a testament to the collaborative efforts between private owners and state agencies in safeguarding communities against the impacts of climate change. While not under the jurisdiction of federal agencies, the dike's role in flood protection highlights the need for continuous monitoring and maintenance to ensure its effectiveness in mitigating potential risks. As water resource enthusiasts and climate advocates, understanding the significance of structures like Sea Horse Ranch Dike is crucial in promoting sustainable water management practices for the future.
Year Completed |
1961 |
Dam Length |
165 |
River Or Stream |
Tr-Gillis Slough |
Primary Dam Type |
Earth |
Surface Area |
75 |
Hydraulic Height |
15 |
Drainage Area |
0.3 |
Nid Storage |
75 |
Structural Height |
15 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
15 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
Sea Horse Ranch Dike
State Route 109 1301-1399, Hoquiam