Dejong Bros. 12 dam
Dejong Bros. 12
Dejong Bros. 12 is a privately owned dam located in Lyman, South Dakota, along the White River Offstream. Constructed in 1962, this earth dam stands at a height of 28 feet and spans 308 feet in length. With a storage capacity of 18 acre-feet and a maximum discharge rate of 2310 cubic feet per second, this low hazard potential dam serves as a critical water resource infrastructure in the region.
Managed by the Natural Resources Conservation Service and regulated by the South Dakota Department of Environment and Natural Resources, Dejong Bros. 12 undergoes regular inspections and enforcement to ensure its structural integrity and operational efficiency. Despite being in operation for nearly six decades, its condition assessment remains unrated, indicating a need for further evaluation to assess any potential risks and implement necessary risk management measures. Additionally, the dam has not yet been assigned an Emergency Action Plan or inundation maps, highlighting areas for improvement in emergency preparedness and response.
While Dejong Bros. 12 plays a vital role in water resource management in South Dakota, there is still room for enhancement in terms of risk assessment, emergency planning, and overall infrastructure maintenance. With its strategic location and historical significance, it is essential for stakeholders to prioritize the safety and sustainability of this dam to ensure the continued availability of water resources for the surrounding communities and ecosystems.
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 Dejong Bros. 12 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| White R Near Oacoma Sd | 100 cfs | → |
| White River Near White River | 17 cfs | → |
| Keya Paha R Near Keyapaha Sd | 23 cfs | → |
| Bad R Near Fort Pierre Sd | 4 cfs | → |
| Little White R Below White River Sd | 107 cfs | → |
| Keya Paha R At Wewela Sd | 52 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Dejong Bros. 12.
Track Dejong Bros. 12 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 Dejong Bros. 12
Where does the data for Dejong Bros. 12 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 Dejong Bros. 12.