County Line Dam dam
County Line Dam
County Line Dam, located in Custer, South Dakota, is a privately owned Earth dam built in 1945 on a tributary of the Cheyenne River. Standing at a height of 26 feet with a length of 950 feet, the dam has a storage capacity of 780 acre-feet, with a normal storage level of 660 acre-feet. Although not rated for its condition, the dam has a low hazard potential and is regulated by the South Dakota Department of Environment and Natural Resources.
Situated in a picturesque location, County Line Dam serves as a vital water resource for the surrounding area, providing irrigation for agriculture and supporting wildlife habitats. Despite its age, the dam continues to play a crucial role in managing water flow and ensuring water security in the region. With its close proximity to the Omaha District of the US Army Corps of Engineers, the dam is subject to regular inspection and enforcement to maintain its operational integrity.
As a significant infrastructure project in the region, County Line Dam represents a historical landmark that showcases the intersection of water resource management and climate resilience. With its strategic location and impact on the local ecosystem, the dam stands as a testament to the importance of sustainable water management practices in the face of changing climate conditions. Enthusiasts and experts alike can appreciate the role of County Line Dam in safeguarding water resources and adapting to the challenges of a shifting climate landscape.
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 County Line Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Cheyenne R Near Buffalo Gap Sd | 56 cfs | → |
| Cheyenne River At Redshirt | 62 cfs | → |
| Beaver Cr Near Buffalo Gap Sd | 2 cfs | → |
| Battle Cr Below Hermosa Sd | 2 cfs | → |
| White R Near Oglala Sd | 101 cfs | → |
| Horsehead Cr At Oelrichs Sd | · | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near County Line Dam.
Boat launches
- Fall River County
- South Boat Ramp Road Fall River County
- Sheps Canyon Road Fall River County
- County Highway 6d Fall River County
Campgrounds
- French Creek
- French Creek Campground
- French Creek Camping Area
- Angostura State Rec Area
- Elk Mountain Campground
- Elk Mountain - Wind Cave National Park
Track County Line 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 County Line Dam
Where does the data for County Line 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 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 County Line Dam.