Harlowton Sewage Lagoon dam
Harlowton Sewage Lagoon
The Harlowton Sewage Lagoon, located in Shawmut, Montana, is a vital water resource management facility owned by the local government. This sewage lagoon plays a crucial role in treating wastewater and protecting the environment by ensuring compliance with state regulations and permitting requirements. Completed in 1958, this earth dam structure has a height of 10 feet and a storage capacity of 190 acre-feet, serving as a key component in the management of wastewater in the region.
Situated near the Musselshell River offstream, the Harlowton Sewage Lagoon covers a surface area of 19.7 acres and has a drainage area of 21.2 acres. Despite its low hazard potential, the facility has not been rated for condition assessment since its last inspection in 1979. While there have been no reported modifications or assessments in recent years, the lagoon continues to serve its primary purpose effectively. With a normal storage capacity of 129 acre-feet and a maximum discharge rate of 6 cubic feet per second, the facility plays a critical role in maintaining water quality and environmental sustainability in Wheatland County, Montana.
The Harlowton Sewage Lagoon stands as a testament to responsible water resource management in the region, with a focus on environmental protection and regulatory compliance. As a state-regulated facility under the jurisdiction of the Department of Natural Resources and Conservation (DNRC), the lagoon serves as a model for efficient wastewater treatment and disposal. Despite its age, the facility's low hazard potential and continued operation underscore its essential role in safeguarding public health and the environment through effective water management practices.
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 Harlowton Sewage Lagoon -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Musselshell River At Harlowton Mt | 188 cfs | → |
| Musselshell River Ab Mud Cr Nr Shawmut Mt | 90 cfs | → |
| Musselshell River Nr Martinsdale | 175 cfs | → |
| South Fork Musselshell R Ab Martinsdale Mt | 43 cfs | → |
| Boulder River At Big Timber Mt | 1,370 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Harlowton Sewage Lagoon.
Campgrounds
- Chief Joseph City Park
- Deadmans Basin - Fas
- Jellison Place Campground
- Selkirk Fas
- Jellison Place
- Haymaker Dispersed Camping Area
Fishing spots
- Big Elk Creek
- Deadmans Basin Reservoir
- East Fork Cottonwood Creek
- Flagstaff Reservoir
- Druckmiller Lake
- Ackley Lake Feeder Canal
Paddle runs
Track Harlowton Sewage Lagoon 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 Harlowton Sewage Lagoon
Where does the data for Harlowton Sewage Lagoon 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 Harlowton Sewage Lagoon.