Pool No. 21 dam
Pool No. 21
Pool No. 21, located in Thief River Falls, Minnesota, is a federally owned earth dam completed in 1971 with a primary purpose of "Other." This dam stands at a height of 8 feet and spans a length of 1300 feet, providing a maximum storage capacity of 5370 acre-feet. The dam is situated on the Mud River and is under the jurisdiction of the Omaha District of the US Army Corps of Engineers.
Despite its low hazard potential, Pool No. 21 plays a crucial role in managing water resources in the area. With a normal storage capacity of 2100 acre-feet and a maximum discharge capability of 1400 cubic feet per second, this dam helps regulate water flow and mitigate flooding risks in the region. Although not currently rated for condition assessment, regular inspections are conducted every 8 years to ensure the safety and functionality of the structure.
Water resource and climate enthusiasts interested in the infrastructure that supports sustainable water management practices will find Pool No. 21 a fascinating feat of engineering. This structure not only serves as a vital component of the local water management system but also reflects the importance of maintaining and monitoring such critical infrastructure to ensure the resilience of water resources in the face of changing climate conditions.
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 Pool No. 21 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Thief River Near Thief River Falls | 289 cfs | → |
| Red Lake River At High Landing Nr Goodridge | 311 cfs | → |
| Roseau River Below South Fork Near Malung | 44 cfs | → |
| Clearwater River At Plummer | 79 cfs | → |
| Lost River At Oklee | 52 cfs | → |
| Roseau River At Ross | 358 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Pool No. 21.
Track Pool No. 21 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 Pool No. 21
Where does the data for Pool No. 21 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 Pool No. 21.