Jeffers Upper dam
Jeffers Upper
Jeffers Upper, located in Prior Lake, Minnesota, is a recreational dam managed by the local government and designed by the USDA NRCS. The dam, completed in 1981, stands at a height of 10 feet with a length of 133 feet, providing a storage capacity of 321 acre-feet. Situated on the Minnesota River, the dam's primary purpose is for recreation, offering a surface area of 3 acres for activities such as boating and fishing.
Despite its low hazard potential and satisfactory condition assessment, Jeffers Upper is subject to state regulation and inspection by the Minnesota Department of Natural Resources. The dam features an uncontrolled spillway and outlet gates, with a moderate risk assessment rating of 3. The surrounding area of Scott County, Minnesota, benefits from this structure for water resource management and flood control along the Minnesota River.
Overall, Jeffers Upper serves as both a functional and recreational asset for the community, showcasing the importance of sustainable water resource management and climate resilience in the region. With its earth dam construction and stone core types, the dam exemplifies the collaboration between local government and federal agencies to ensure the safety and enjoyment of residents and visitors alike.
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 Jeffers Upper -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Minnesota River Near Jordan | 11,800 cfs | → |
| Minnesota River At Fort Snelling State Park | 6,620 cfs | → |
| Vermillion River Near Empire | 42 cfs | → |
| Mississippi River At St. Paul | 18,100 cfs | → |
| Shingle Creek At Queen Ave In Minneapolis | 19 cfs | → |
| High Island Creek Near Henderson | 72 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Jeffers Upper.
Boat launches
- Townline Avenue 14193, Shakopee
- Townline Avenue 14554, Shakopee
- Cr 101 Shakopee
- Staring Lake Parkway Eden Prairie
- Blakeney Road Eden Prairie
- Crystal Lake Road East 60, Burnsville
Track Jeffers Upper 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 Jeffers Upper
Where does the data for Jeffers Upper 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 Jeffers Upper.