Nielsen Dam C Reservoir Report
Nearby: Nielsen Dam B Nielsen Dam A
Last Updated: December 15, 2025
Nielsen Dam C, located in Bothell, Washington, is a privately owned structure that serves the primary purpose of recreation.
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Summary
Built in 1973, this earth dam stands at a hydraulic height of 9 feet and has a length of 250 feet, providing a surface area of 12 acres for recreational activities. Despite its modest size, the dam has a high hazard potential and is currently in poor condition as assessed in 2018. The dam is situated on Tr-North Creek and is under the regulatory oversight of the Washington Department of Ecology, ensuring state permitting, inspection, and enforcement.
With a maximum storage capacity of 16 acre-feet and a normal storage capacity of 12 acre-feet, Nielsen Dam C plays a crucial role in managing water resources in the Snohomish County area. The dam's drainage area covers 0.15 square miles, with a maximum discharge rate of 4 cubic feet per second. However, the dam's poor condition and high hazard potential highlight the need for regular maintenance and potential risk management measures to ensure the safety of surrounding communities. Despite these challenges, the dam continues to attract visitors for recreational purposes, offering a serene escape in the midst of a bustling city.
As a significant structure in the region, Nielsen Dam C stands as a reminder of the delicate balance between water resource management and recreational opportunities. With its proximity to Bothell and the surrounding areas, the dam serves as a valuable asset for outdoor enthusiasts and nature lovers alike. However, ongoing efforts are required to address the dam's poor condition and high hazard potential, emphasizing the importance of proactive maintenance and risk management strategies to safeguard both the dam and the communities it serves.
Year Completed |
1973 |
Dam Length |
250 |
River Or Stream |
Tr-North Creek |
Primary Dam Type |
Earth |
Surface Area |
12 |
Hydraulic Height |
9 |
Drainage Area |
0.15 |
Nid Storage |
16 |
Structural Height |
9 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
9 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Thornton Creek Near Seattle
|
41cfs |
Snohomish River Near Monroe
|
28500cfs |
Pilchuck River Near Snohomish
|
1020cfs |
Mercer Creek Near Bellevue
|
12cfs |
Snoqualmie River Near Carnation
|
9660cfs |
Issaquah Creek Near Mouth Near Issaquah
|
300cfs |
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.
Nielsen Dam C
Sammamish Lake Near Redmond
68th Avenue Northeast 17181-17299, Kenmore