O'Neal Miller Dam dam
O'Neal Miller Dam
O'Neal Miller Dam, located in Aiken, South Carolina, is a private-owned structure that serves primarily for recreational purposes. Completed in 1955, this earth dam stands at a height of 31 feet and stretches to a length of 515 feet, with a storage capacity of 284 acre-feet. Situated on the Big Branch river, the dam offers a surface area of 13 acres for water-based activities and enjoyment.
Despite its recreational value, O'Neal Miller Dam poses a high hazard potential with a poor condition assessment as of August 2017. The dam is regulated by the South Carolina Department of Health and Environmental Control (DHEC), which oversees its permitting, inspection, and enforcement. With its design classified as buttress earth, the dam's foundation type is listed as unknown, raising questions about its long-term structural integrity and safety.
For water resource and climate enthusiasts, O'Neal Miller Dam serves as a focal point for understanding the balance between human recreational needs and environmental safety. As a privately owned structure with limited federal involvement, the dam's management and maintenance are crucial in ensuring the safety of both visitors and the surrounding ecosystem. With its location in the Savannah District and close proximity to the Congaree National Park, the dam stands as a reminder of the delicate relationship between water resources, recreation, and environmental stewardship in the face of changing climate patterns and increasing water resource demands.
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 O'Neal Miller Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Mctier Creek (Rd 209) Near Monetta | 20 cfs | → |
| Saluda River Below Lk Murray Dam Nr Columbia | 770 cfs | → |
| South Fork Edisto River Near Denmark | 262 cfs | → |
| Saluda River Near Columbia | 2,670 cfs | → |
| Congaree River At Columbia | 10,200 cfs | → |
| Smith Branch At North Main St At Columbia | 4 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near O'Neal Miller Dam.
Boat launches
- Savannah Highway Neeses
- Cabana Way Lexington County
- Sandlapper Way 159, Lexington County
- Eastshore Drive 143, Lexington County
- Shull Island Boat Ramp
- Highway 6 6, Columbia
Campgrounds
Fishing spots
Track O'Neal Miller 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 O'Neal Miller Dam
Where does the data for O'Neal Miller 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 High 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 O'Neal Miller Dam.