Thompson Mill Dam (In-Channel) dam
Thompson Mill Dam (In-Channel)
Thompson Mill Dam (In-Channel) is a historic stone dam located on the Big Blue River in Johnson County, Indiana. Built in 1884, this dam stands at a height of 10 feet and stretches 300 feet in length, creating a reservoir with a storage capacity of 321 acre-feet. The dam serves a primarily recreational purpose, with a surface area of 64 acres and a drainage area of 581.15 square miles.
Despite being classified as having a low hazard potential, Thompson Mill Dam is considered to be at high risk due to its age and condition. A condition assessment in 2012 rated the dam as fair, with the last inspection conducted in 2017. The dam is regulated by the Indiana Department of Natural Resources, with inspection, permitting, and enforcement protocols in place to ensure its safety and compliance with state regulations. While there are no spillways or outlet gates associated with the dam, it remains a notable structure within the Louisville District of the US Army Corps of Engineers.
Enthusiasts of water resources and climate will find Thompson Mill Dam an intriguing subject for study, given its historical significance, design characteristics, and risk assessment profile. The dam's location on the Big Blue River in Indiana, along with its unique features and regulatory oversight, make it a valuable case study for understanding the intersection of infrastructure, natural resources, and environmental management in the context of climate change and water resource conservation efforts.
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 Mill Dam (In-Channel) -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Sugar Creek Near Edinburgh | 4,340 cfs | → |
| Driftwood River Near Edinburgh Ind | 9,520 cfs | → |
| Youngs Creek Near Edinburgh Ind | 1,480 cfs | → |
| Flatrock River At Columbus | 3,500 cfs | → |
| Haw Creek Near Clifford | 915 cfs | → |
| East Fork White River At Columbus | 13,400 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Thompson Mill Dam (In-Channel).
Boat launches
- Us 31 Edinburgh
- River Road Johnson County
- South Mauxferry Road Johnson County
- County Road 550 South 3427, Franklin
- Tannehill Road Bartholomew County
Campgrounds
- Irwin City Park
- Camp Atterbury Military
- Heflen Co Park
- Johnson County Park
- Happy Hollow’S Children Camp
- Brown County State Park
Paddle runs
Track Thompson Mill Dam (In-Channel) 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 Mill Dam (In-Channel)
Where does the data for Thompson Mill Dam (In-Channel) 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 Low 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 Mill Dam (In-Channel).