Old Longs Mill Dam dam
Old Longs Mill Dam
Old Longs Mill Dam, also known as Tratebas Mill Dam, is a private-owned structure located in Porter, Indiana, along Coffee Creek. Built in 1930, this earth dam stands at a height of 20 feet and stretches 200 feet in length, providing a surface area of 10.25 acres and a storage capacity of 81 acre-feet. While its primary purpose is for recreation, the dam is regulated by the Indiana Department of Natural Resources (IDNR) and undergoes regular inspections to ensure its safety and compliance with state regulations.
Despite its historical significance and recreational value, Old Longs Mill Dam poses a significant hazard potential due to its poor condition assessment. With a high risk rating of 2, there are concerns about the dam's ability to withstand potential emergencies and protect downstream areas from flooding. Although currently lacking an Emergency Action Plan (EAP) and updated risk assessment measures, efforts are being made to address these deficiencies and mitigate any potential risks associated with the dam.
As a popular spot for outdoor enthusiasts and nature lovers, the Old Longs Mill Dam serves as a reminder of the importance of maintaining and monitoring water resource infrastructure to ensure the safety of both the environment and nearby communities. With ongoing assessments and potential risk management measures in place, stakeholders are working towards safeguarding this historic structure and its surrounding ecosystem for future generations to enjoy.
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 Old Longs Mill Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Little Calumet River At Porter | 38 cfs | → |
| Burns Ditch At Portage | 121 cfs | → |
| Deep River At Lake George Outlet At Hobart | 32 cfs | → |
| Trail Creek At Michigan City Harbor | 106 cfs | → |
| Trail Creek At Michigan City | 51 cfs | → |
| Grand Calumet River At Industrial Hwy At Gary | 446 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Old Longs Mill Dam.
Boat launches
- Wesley Road Porter County
- Grand Boulevard 2313, Lake Station
- Stone Lake Public Boat Launch
- Oak Savannah Trail, Merrillville
- Lake Michigan, New Buffalo, Berrien County
- W 100 N Starke County
Campgrounds
- Camp Lawrence
- Indiana Dunes State Park
- State Park
- Dunewood - Indiana Dunes National Lakeshore
- Dunewood Campground
- Camp Shabbona Woods
Fishing spots
Track Old Longs Mill 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 Old Longs Mill Dam
Where does the data for Old Longs Mill 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 Old Longs Mill Dam.