Deer Park Sewage Treatment Lagoon Reservoir Report
Last Updated: December 15, 2025
Deer Park Sewage Treatment Lagoon, located in Spokane, Washington, is a vital facility owned and regulated by the local government.
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Summary
This lagoon plays a crucial role in wastewater treatment and is state-regulated by the Washington Department of Ecology. With a hydraulic height of 18.1 feet and a structural height of 17.9 feet, this earth-type dam was completed in 1984 and has a normal storage capacity of 24.7 acre-feet.
Despite its importance, the Deer Park Sewage Treatment Lagoon has been flagged with a high hazard potential and poor condition assessment. The last inspection in May 2019 highlighted the need for improvements and more frequent assessments due to its critical role in managing sewage in the region. With a drainage area of 0.04 square miles and a surface area of 21 acres, the lagoon's capacity to handle wastewater and maintain water quality for Tr-Dragoon Creek is paramount to its surrounding environment.
As water resource and climate enthusiasts, it is crucial to monitor the condition and regulatory compliance of facilities like the Deer Park Sewage Treatment Lagoon to ensure the protection of water quality and environmental stability. With potential risks identified and a history of poor conditions, efforts to improve and maintain this facility are essential for the health and sustainability of the surrounding ecosystem.
Year Completed |
1984 |
Dam Length |
2112.5 |
River Or Stream |
Tr-Dragoon Creek-Offstream |
Primary Dam Type |
Earth |
Surface Area |
21 |
Hydraulic Height |
18.1 |
Drainage Area |
0.04 |
Nid Storage |
24.7 |
Structural Height |
17.9 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
18 |
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.
Deer Park Sewage Treatment Lagoon