Hill Annex No. 3 dam
Hill Annex No. 3
Located in Itasca County, Minnesota, Hill Annex No. 3 is a privately owned earth dam constructed in 1954 for tailings management. This dam, standing at a height of 63 feet and spanning 10,700 feet in length, serves the primary purpose of tailings storage with a storage capacity of 3,346 acre-feet. The dam is regulated by the Minnesota Department of Natural Resources (MNDNR EWR) and is subject to state permitting, inspection, and enforcement.
The dam poses a significant hazard potential and has not been rated for its condition assessment as of the last inspection in July 2012. It falls under the jurisdiction of local residents and the St. Paul District of the US Army Corps of Engineers. The dam's primary source agency is the state of Minnesota, and it is situated along the Swan River-Tr. With a drainage area of 0.4 square miles, the dam plays a crucial role in managing water resources in the region and highlights the importance of proper dam maintenance and regulation for climate and water resource enthusiasts.
Despite being a privately owned structure, Hill Annex No. 3's presence underscores the interconnectedness of water resources management, climate resilience, and regulatory oversight. As a key component in the local watershed system, the dam's condition and functionality are essential for ensuring the safety and sustainability of water resources in the area. With its significant hazard potential and state-regulated status, this dam serves as a focal point for ongoing monitoring, inspection, and enforcement efforts to safeguard both the environment and local communities from potential risks associated with dam failure or mismanagement.
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 Hill Annex No. 3 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Prairie River Near Taconite | 146 cfs | → |
| Mississippi River At Grand Rapids | 247 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Hill Annex No. 3.
Boat launches
Campgrounds
- Nashwauk Campground
- Kom-On-In Beach Campground
- American Legion Park - Warba
- Warba American Legion
- American Legion Park
- Itasca County Fairgrouds Campground
Fishing spots
Paddle runs
- The Confluence Of The Prairie River To The Boundary Of Logan And Workman Townships
- Lake Winnigigoshish To Blackwater Lake
- Dora Lake To State Highway 6
- The Boundary Between Logan And Workman Townships In Aitkin County To The Dam Entrance Of The Flood Diversion Channel
- The Discharge Of The Flood Diversion Channel To Riverton
Track Hill Annex No. 3 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 Hill Annex No. 3
Where does the data for Hill Annex No. 3 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 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 Hill Annex No. 3.