W. Mann No.3 dam
W. Mann No.3
W. Mann No.3 is a private earth dam located on the TR CHEYENNE river in Meade, South Dakota. Completed in 1956, this dam stands at a height of 15 feet and has a storage capacity of 72 acre-feet, with a normal storage level of 44 acre-feet. The dam serves the primary purpose of water resource management and flood control, with a maximum discharge capacity of 2000 cubic feet per second.
Managed by the South Dakota Department of Environment and Natural Resources (DENR), W. Mann No.3 is regulated, inspected, and enforced by state authorities to ensure its structural integrity and operational safety. Despite being rated as having a low hazard potential and not having a current condition assessment, the dam continues to play a crucial role in water management in the region. With no emergency action plan or inundation maps prepared, there is room for improvement in disaster preparedness and risk management for this water resource infrastructure.
Overall, W. Mann No.3 represents a key component of the water infrastructure in Meade County, South Dakota, contributing to water supply stability and flood protection along the TR CHEYENNE river. As climate change continues to impact water resources, the maintenance and monitoring of dams like W. Mann No.3 will be essential in ensuring the resilience of water systems in the face of changing environmental 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 W. Mann No.3 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Cheyenne R Near Plainview Sd | 4,730 cfs | → |
| Belle Fourche River Near Elm Springs | 411 cfs | → |
| Elk Cr Near Elm Springs Sd | 2 cfs | → |
| Moreau R Near Faith Sd | 135 cfs | → |
| Belle Fourche R Near Sturgis Sd | 312 cfs | → |
| Cheyenne River Near Wasta | 2,480 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near W. Mann No.3.
Track W. Mann No.3 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 W. Mann No.3
Where does the data for W. Mann No.3 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 W. Mann No.3.