Larson No. 2 dam
Larson No. 2
Larson No. 2 is a privately-owned earth dam located in Mellette, South Dakota, on the TRIB-ROUNDUP CREEK. It was completed in 1964 and stands at a height of 29 feet, with a length of 250 feet. The dam has a storage capacity of 16 acre-feet, with a maximum discharge of 168 cubic feet per second. Despite being classified as having a low hazard potential and not currently rated for condition, Larson No. 2 is regulated, permitted, inspected, and enforced by the South Dakota Department of Environment and Natural Resources (DENR).
Water resource and climate enthusiasts will be intrigued by the location of Larson No. 2, as it serves as a vital structure in the St. Paul District managed by the U.S. Army Corps of Engineers. The dam's purpose and associated structures are not specified, but its presence on Roundup Creek highlights its importance in water management and flood control within the region. While the dam has not been assessed for condition or emergency action plan readiness, its regulation and oversight by the state ensure that it meets safety standards and operational guidelines.
Given its historical significance and essential role in water management, Larson No. 2 presents a unique opportunity for further exploration and study by water resource and climate enthusiasts. The dam's relatively low hazard potential, combined with its state jurisdiction and inspection history, make it a noteworthy structure in the landscape of South Dakota's water infrastructure. Understanding the design, function, and regulation of Larson No. 2 can provide valuable insights into the intersection of water resources, climate resilience, and dam safety in the region.
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 Larson No. 2 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Black Pipe Creek Nr Belvidere | 13 cfs | → |
| White River Near White River | 40 cfs | → |
| Little White R Below White River Sd | 112 cfs | → |
| White R Near Kadoka Sd | 83 cfs | → |
| Little White R Near Rosebud Sd | 141 cfs | → |
| South Fork Bad R Near Cottonwood Sd | · | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Larson No. 2.
More reservoirs
Track Larson No. 2 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 Larson No. 2
Where does the data for Larson No. 2 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 Larson No. 2.