Nielsen Dam B dam
Nielsen Dam B
Nielsen Dam B, located in Bothell, Washington, is a privately owned structure regulated by the Washington Department of Ecology. Built in 1973, this earth dam primarily serves recreational purposes along Tr-North Creek. With a hydraulic height of 10 feet and a structural height of 9 feet, the dam has a storage capacity of 11 acre-feet and a drainage area of 0.08 square miles.
Despite its recreational focus, Nielsen Dam B has a high hazard potential and is currently rated as being in poor condition. The last inspection in August 2017 revealed the need for improvements, with a scheduled inspection frequency of every 5 years. The dam's emergency action plan status, risk assessment, and inundation maps are currently not updated or in compliance with guidelines.
The dam's location within Snohomish County, Washington, adds to its significance for water resource and climate enthusiasts. With the potential for environmental impact and the importance of maintaining its structural integrity, Nielsen Dam B stands as a reminder of the ongoing challenges and responsibilities associated with managing water resources in the region.
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.
- 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.
- 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.
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, environmental 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.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Nielsen Dam B -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Thornton Creek Near Seattle | 41 cfs | → |
| Snohomish River Near Monroe | 6,190 cfs | → |
| Pilchuck River Near Snohomish | 255 cfs | → |
| Mercer Creek Near Bellevue | 12 cfs | → |
| Snoqualmie River Near Carnation | 1,440 cfs | → |
| Issaquah Creek Near Mouth Near Issaquah | 43 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Nielsen Dam B.
Boat launches
- 68th Avenue Northeast 17181-17299, Kenmore
- Beach Drive Northeast 17218, Lake Forest Park
- East Shore Drive Snohomish County
- Sammamish River Trail Redmond
- High Bridge, Monroe
- West Lake Sammamish Parkway Northeast Redmond
Campgrounds
- Fay Bainbridge State Park Campsite
- Fay Bainbridge State Park
- Flowing Lake County Park
- Site 40
- Site 39
- Site 38
Paddle runs
- Snoqualmie Falls To Plum's Landing
- Headwaters In Ne1/4 Of Sec 14, T29n, R10e To Confluence With Canyon Creek
- Confluence With Taylor River To Confluence With North Fork Snoqualmie River
- Wagner Bridge To Confluence With Middle Fork Snoqualmie River
- Confluence Of Tye And Foss Rivers To Gold Bar
- Confluence With Troublesome Creek To Confluence With South Fork Skykomish River
Track Nielsen Dam B in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Nielsen Dam B
Where does the data for Nielsen Dam B come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the High hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Nielsen Dam B.