Johnston dam
Johnston
Johnston, also known as Johnston Surprise, is a federal-owned fish and wildlife pond located in Bayfield, Wisconsin. Completed in 1960, the dam stands at a height of 10 feet and has a hydraulic height of 5 feet. With a storage capacity of 120 acre-feet, Johnston serves as a vital resource for supporting the local ecosystem and wildlife in the area.
Despite its low hazard potential and fair condition assessment, Johnston poses a moderate risk level (3) according to the data. The dam has a controlled spillway type and covers a surface area of 15 acres, with a drainage area of 1.2 square miles. The last inspection of Johnston took place on May 30, 2019, with an inspection frequency of every 10 years.
While Johnston has not undergone any significant modifications in recent years, it remains an important structure for the conservation of fish and wildlife in the region. As climate change continues to impact water resources, Johnston serves as a reminder of the crucial role that well-maintained dams and ponds play in maintaining biodiversity and ecological balance in our changing environment.
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 Johnston -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Namekagon River At Leonards | 138 cfs | → |
| Bad River Near Mellen | 101 cfs | → |
| White River Near Ashland | 245 cfs | → |
| North Fish Creek Near Moquah | 55 cfs | → |
| Bad River Near Odanah | 390 cfs | → |
| Whittlesey Creek Near Ashland | 16 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Johnston.
Boat launches
- South Garden Avenue 25299, Town Of Namakagon
- Namekagon Lake -- Access Off Missionary Point Lane
- Namekagon Lake -- County Highway D Access
- Namekagon Lake -- Funnys Ln Access
- Atkins Lake -- Access
- Diamond Lake -- Access At Off Pioneer Rd
Campgrounds
- Namekagon
- Namekagon Lake Recreation Area
- Namekagon Lake Recreation Area Campgrounds
- Day Lake Recreation Area
- Day Lake
- Day Lake Recreation Area Campground
Paddle runs
- East Forest Boundary To Forest Road 162 Crossing
- Forest Road 162 Crossing To Bridge On Blaisdell Lake
- Forest Road 149 To West Forest Boundary
- Forest Road 148 To Forest Road 149
- Forest Road 144 To Forest Road 148
- Footbridge To Forest Road 144
More reservoirs
Track Johnston 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 Johnston
Where does the data for Johnston 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 Johnston.