Oscar Diess dam
Oscar Diess
Oscar Diess, located in Lyman, South Dakota, is a privately owned dam regulated by the Department of Environment and Natural Resources. Built in 1953, this earth-type dam stands at a height of 22 feet and has a storage capacity of 63 acre-feet. With a low hazard potential and a current condition assessment of "Not Rated," Oscar Diess plays a crucial role in managing water resources in the area and ensuring the safety of surrounding communities.
Managed by the Natural Resources Conservation Service, Oscar Diess serves the primary purpose of regulating water flow in the Whiteriver Offstream, with a maximum discharge capacity of 438 cubic feet per second. Despite its age, the dam remains operational and compliant with state regulations for inspection, permitting, and enforcement. While the dam has not been rated for condition assessment, its low hazard potential indicates a relatively low risk of failure.
As a key component of the St. Paul District's water resource infrastructure, Oscar Diess contributes to flood control, irrigation, and water supply management in the region. While the dam has not been assigned an Emergency Action Plan (EAP) or undergone recent risk assessments, its presence highlights the importance of maintaining and monitoring water infrastructure to ensure the continued resilience of communities and ecosystems in South Dakota.
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 Oscar Diess -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| White R Near Oacoma Sd | 100 cfs | → |
| Bad R Near Fort Pierre Sd | 4 cfs | → |
| Platte Creek Near Platte | 0 cfs | → |
| White River Near White River | 17 cfs | → |
| Keya Paha R Near Keyapaha Sd | 23 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Oscar Diess.
Boat launches
- Oacoma
- East Glenn Avenue 309, Chamberlain
- Joe Creek Boat Ramp
- Lyman County
- Chaney Rush Road Hughes County
Campgrounds
- Byre Lake Recreation Area
- Dude Rach Dfg
- West Chamberlain - Lake Francis Case
- Iron Nation - Lake Sharpe
- Left Tailrace - Lake Sharpe
- Right Tailrace - Coe
More reservoirs
Track Oscar Diess 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 Oscar Diess
Where does the data for Oscar Diess 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 Oscar Diess.