Selvin Johnson dam
Selvin Johnson
Selvin Johnson is a privately owned earth dam located in Pennington, South Dakota, along the TR Cheyenne river. Built in 1935, this dam stands at a height of 26 feet and has a length of 450 feet, offering a storage capacity of 80 acre-feet. While its primary purpose and associated structures are not specified, Selvin Johnson is regulated by the South Dakota Department of Environment and Natural Resources (DENR), with state permitting, inspection, and enforcement all in place.
Managed by a private owner, Selvin Johnson has a low hazard potential and a condition assessment that is currently not rated. Despite lacking specific data on spillway type, outlet gates, and inspection frequency, the dam is deemed to meet safety guidelines by authorities. Situated within the St. Paul District of the US Army Corps of Engineers, Selvin Johnson plays a crucial role in water resource management in the region, contributing to flood control and ensuring a stable water supply for local communities.
With a long history of serving the area, Selvin Johnson remains an essential infrastructure for water management in Pennington County. While additional details on its operation and maintenance may be warranted, the dam's presence underscores the importance of effective regulation and oversight in safeguarding water resources and mitigating potential risks associated with dam infrastructure in a changing climate. As water resource and climate enthusiasts, staying informed about structures like Selvin Johnson is vital for promoting sustainable practices and resilience in the face of environmental challenges.
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 Selvin Johnson -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Elk Cr Near Elm Springs Sd | 1 cfs | → |
| Cheyenne R Near Plainview Sd | 239 cfs | → |
| Belle Fourche River Near Elm Springs | 98 cfs | → |
| Cheyenne River Near Wasta | 65 cfs | → |
| South Fork Bad R Near Cottonwood Sd | · | → |
| Rapid Cr Near Farmingdale Sd | 20 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Selvin Johnson.
Track Selvin Johnson 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 Selvin Johnson
Where does the data for Selvin Johnson 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 Selvin Johnson.