I405 Coal Creek Stormwater Detention Da Reservoir Report
Last Updated: December 15, 2025
The I405 Coal Creek Stormwater Detention Dam, located in Newport Shores, Washington, was completed in 1987 with the primary purpose of flood risk reduction along Coal Creek.
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Summary
This earth dam structure has a hydraulic height of 31 feet and a storage capacity of 40 acre-feet, helping to manage stormwater runoff and protect the surrounding area from potential flooding events. The dam is owned and regulated by the Washington Department of Ecology, with state permitting, inspection, and enforcement ensuring its continued functionality and safety.
With a low hazard potential and a condition assessment of "Not Rated," the I405 Coal Creek Stormwater Detention Dam serves as a vital infrastructure asset in the region. While there are no associated structures or outlet gates, the dam's design and construction provide essential flood protection for the community. The dam's location within Congressional District 09, Washington, underlines the importance of proper water resource management and climate resilience measures in safeguarding against potential environmental risks and ensuring the safety of nearby residents.
As water resource and climate enthusiasts, it is crucial to recognize and appreciate the role of structures like the I405 Coal Creek Stormwater Detention Dam in mitigating flood risks and managing stormwater runoff in environmentally sensitive areas. By understanding the dam's design, purpose, and regulatory oversight, we can support ongoing efforts to enhance water infrastructure resilience and ensure the long-term sustainability of our communities in the face of changing climate patterns and increasing environmental challenges.
Year Completed |
1987 |
River Or Stream |
Coal Creek |
Primary Dam Type |
Earth |
Surface Area |
1 |
Hydraulic Height |
31 |
Nid Storage |
40 |
Structural Height |
31 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
31 |
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.
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