Margaret Lake Dam dam
Margaret Lake Dam
Margaret Lake Dam, located in King County, Washington, is a privately owned structure that serves primarily for recreational purposes. Built in 1933, this earth dam stands at a hydraulic height of 41 feet and has a structural height of 38 feet, with a length of 480 feet. The dam has a storage capacity of 1210 acre-feet, with a normal storage level of 820 acre-feet. It spans the Margaret Creek and covers a surface area of 52 acres, contributing to the overall watershed's drainage area of 2.86 square miles.
Despite its age, Margaret Lake Dam is still in fair condition, as assessed in July 2020, with a high hazard potential due to its location and storage capacity. The dam has undergone inspections every five years, as per regulatory requirements by the Washington Department of Ecology. The structure has no outlet gates or spillway type specified in the data, indicating potential limitations in its ability to manage water discharge during high flow events. With its historical significance and recreational value, the dam continues to be an important feature in the region, requiring careful monitoring and maintenance to ensure public safety and environmental protection in the face of changing climate conditions.
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 Margaret Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Tolt River Near Carnation | 279 cfs | → |
| North Fork Tolt River Near Carnation | 68 cfs | → |
| Snoqualmie River Near Carnation | 1,440 cfs | → |
| Sf Tolt River Bl Regulating Basin Nr Carnation | 80 cfs | → |
| Snohomish River Near Monroe | 6,190 cfs | → |
| South Fork Tolt River Near Carnation | 72 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Margaret Lake Dam.
Boat launches
- Lake Marcel Community Park
- High Bridge, Monroe
- Ben Howard Road 21101-21283, Monroe
- Tualco Loop Road 17829, Monroe
- Stevens Pass Highway Sultan
- Northeast Tolt Hill Road 30348-30762, Carnation
Paddle runs
- Confluence Of Tye And Foss Rivers To Gold Bar
- Confluence With Troublesome Creek To Confluence With South Fork Skykomish River
- Snoqualmie Falls To Plum's Landing
- Confluence With Taylor River To Confluence With North Fork Snoqualmie River
- Wagner Bridge To Confluence With Middle Fork Snoqualmie River
- Alpine Lakes Wilderness Boundary To Quartz Creek Road
Track Margaret Lake Dam 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 Margaret Lake Dam
Where does the data for Margaret Lake Dam 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 Margaret Lake Dam.