Bak #1 Dam
Bak #1
Bak #1 is a state-regulated earth dam located in Mellette, South Dakota, with a significant hazard potential. Completed in 1970, this dam stands at a height of 59 feet and has a storage capacity of 236 acre-feet, making it a crucial water resource structure in the area. The dam is situated on the TR Little White Offstream river or stream, managed by the St. Paul District of the US Army Corps of Engineers.
Despite its importance, Bak #1 has not been rated for its condition assessment, and the last inspection took place in September 2017. With a frequency of inspection set at 3 years, it is crucial to ensure the safety and maintenance of this structure to prevent any potential risks. Additionally, there is no Emergency Action Plan (EAP) prepared for Bak #1, highlighting the need for proactive measures to be taken in case of emergencies or natural disasters that could impact the dam and surrounding areas. For water resource and climate enthusiasts, monitoring and ensuring the integrity of Bak #1 is essential for the sustainable management of water resources in the region.
Inside the reservoir
The real shoreline of this water body, with a depth model scaled so the basin holds exactly its recorded storage. Drag to orbit, scroll to zoom, and use the slider to drain and refill it. Click anywhere on the basin for the modelled depth there.
NID normal pool storage (192 AF) over this shoreline implies a 70 ft basin, deeper than the 59 ft dam. Depth capped to the dam; storage shown is modelled, not NID.
How this is built. The shoreline is the National Hydrography
Dataset polygon for this water body,
matched to the dam by proximity and confirmed by comparing its area with the
National Inventory of Dams surface area.
Depth is modelled, not surveyed: the basin is shaped by distance from
shore — deep in open water, shallow in the bays — and scaled so its
volume equals the recorded storage. No national bathymetric survey exists for
US reservoirs. Treat the shoreline, area and volume as measured, and the depth
distribution as an informed approximation.
Above normal pool, water is shown rising within the normal-pool
shoreline. Where it would actually spread depends on the surrounding
terrain, which is not modelled here — a reservoir in a steep canyon barely
widens, one on flat ground can spread a long way. This is a depth and volume
figure, not an inundation map. Official inundation mapping for a dam
comes from its Emergency Action Plan.
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 Bak #1 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Little White R Below White River Sd | 89 cfs | → |
| White River Near White River | 24 cfs | → |
| Little White R Near Rosebud Sd | 125 cfs | → |
| Black Pipe Creek Nr Belvidere | 16 cfs | → |
| Little White R Near Vetal Sd | 62 cfs | → |
| White R Near Kadoka Sd | 9 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Bak #1.
Boat launches
See all →
About Bak #1
Where does the data for Bak #1 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 Significant 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 below 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.
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.