Thompson Lake Dam dam
Thompson Lake Dam
Thompson Lake Dam, also known as Millsite Dam, is a privately owned earth and gravity dam located in Livingston County, Michigan. Built in 1894, this dam serves primarily for recreational purposes, providing a tranquil and scenic environment for water resource and climate enthusiasts to enjoy. Situated in Howell, Michigan, the dam stands at a height of 19.5 feet and has a storage capacity of 2,320 acre-feet, with a surface area of 260 acres and a drainage area of 10.1 square miles.
Managed by the Michigan Department of Environment, Great Lakes, and Energy (DEGLE), Thompson Lake Dam is regulated, permitted, inspected, and enforced by the state to ensure its safety and functionality. With a controlled spillway and a maximum discharge capacity of 222 cubic feet per second, the dam presents a significant hazard potential, categorized as "Very High (1)" in terms of risk assessment. Despite its fair condition assessment as of November 2018, Thompson Lake Dam continues to be a popular destination for outdoor recreation, attracting visitors interested in water resources and climate-related activities in the area.
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 Thompson Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Huron River Near Hamburg | 277 cfs | → |
| Huron River Near New Hudson | 105 cfs | → |
| Huron River At Milford | 73 cfs | → |
| Red Cedar River Near Williamston | 80 cfs | → |
| Mill Creek Near Dexter | 67 cfs | → |
| Sloan Creek Near Williamston | 2 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Thompson Lake Dam.
Boat launches
- Roosevelt Street 327, Howell
- Conrad Road Genoa Township
- East Schafer Road Hamburg Township
- Indian Lake, 75 Acres, Livingston County
- Bishop Lake Road Hamburg Township
- Appleton Loop Hamburg Township
Campgrounds
- Appleton Lake - Brighton Rec Area
- Bishop Lake - Brighton Rec Area
- Murray Lake - Brighton Rec Area
- Pinckney-Crooked Lake Rustic
- Pinckney State Rec Area
- Group Camp 10
Fishing spots
Track Thompson 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 Thompson Lake Dam
Where does the data for Thompson 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 Significant 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 Thompson Lake Dam.