Jonjak dam
Jonjak
Jonjak is a privately owned earth dam located in Sawyer, Wisconsin, near the Minnemac Lake Outlet. Constructed in 1967 by the USDA NRCS, this dam stands at 11 feet tall and spans 280 feet in length, with a storage capacity of 130 acre-feet. The primary purpose of Jonjak is categorized as "Other," serving as a crucial infrastructure for water resource management in the area.
With a low hazard potential and a moderate risk assessment rating, Jonjak is deemed to be in satisfactory condition, although detailed assessments are currently not available. The dam features uncontrolled spillways and outlet gates, contributing to its functional design. While the dam is not under the jurisdiction of state agencies for regulation, inspection, or enforcement, it is a part of the Detroit District managed by the USDA NRCS.
Water resource and climate enthusiasts interested in the intricate details of Jonjak's design, construction, and operational history will find valuable insights in this data set. The dam's location, dimensions, storage capacity, and associated risk factors provide a comprehensive overview of its significance in managing water flow and storage in the region. As a privately owned structure with federal funding and design support, Jonjak represents a collaborative effort to ensure the safety and efficiency of water management systems in Sawyer, Wisconsin.
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 Jonjak -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Namekagon River At Leonards | 154 cfs | → |
| Chippewa River At Bishops Bridge Near Winter | 600 cfs | → |
| Chippewa River Near Bruce | 1,200 cfs | → |
| St. Croix River Near Danbury | 1,320 cfs | → |
| Flambeau River Near Bruce | 2,210 cfs | → |
| Bois Brule River At Brule | 167 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Jonjak.
Boat launches
- Durphee Lake -- Access Off Cty Highway Kk
- Windigo Park
- Lac Courte Orielles Public Access
- Sand Lake -- Access At E End Of Lake Cth E
- Grindstone Lake -- Access Off Poplar Ave
- Whitefish Lake -- Access Off State Highway 27/70
Campgrounds
- Phipps
- Sawmill Lake County Park
- Sawmill Lake Campground
- Phipps Landing - St. Croix National Scenic River
- Phipps Landing
- Earl Landing - St. Croix National Scenic River
Paddle runs
- Forest Road 162 Crossing To Bridge On Blaisdell Lake
- East Forest Boundary To Forest Road 162 Crossing
- Forest Road 149 To West Forest Boundary
More reservoirs
Track Jonjak 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 Jonjak
Where does the data for Jonjak 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 Jonjak.