Johnson dam
Johnson
Johnson is a privately owned irrigation dam located in Franklin, Idaho, near the city of Preston. Built in 1860, this earth dam stands at a height of 27.6 feet and has a storage capacity of 396 acre-feet. The dam is primarily used for irrigation purposes and is regulated by the Idaho Department of Water Resources.
With a significant hazard potential and a fair condition assessment as of July 2018, Johnson Dam is closely monitored and inspected by state regulatory agencies to ensure its safety and functionality. The dam has a spillway width of 20 feet and features slide gates as outlet controls. Despite being modified over the years, the dam still maintains its original purpose and design, serving as a vital water resource for the surrounding area.
Located along Worm Creek and Cub River, Johnson Dam plays a crucial role in water management and agricultural activities in the region. With a moderate risk assessment and regular inspections, this historic structure continues to contribute to the local economy and environment while highlighting the importance of sustainable water resource management 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 Johnson -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Bear River At Idaho-Utah State Line | 483 cfs | → |
| Logan River Above State Dam | 410 cfs | → |
| Logan | 68 cfs | → |
| Bear River At Pescadero | 494 cfs | → |
| Blacksmith Fork Ab U.P.&L. Co | 74 cfs | → |
| Little Bear River At Paradise | 83 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Johnson.
Boat launches
- West 6200 North 6484, Cache County
- North 3000 West Cache County
- West 3000 North 4507, Cache County
- Highway 30 Cache County
- North Cisco Road Rich County
Campgrounds
- Albert Moser
- Albert Moser Campground
- Marijuana Flat Campground
- Redpoint Recreation Site
- Willow Flat Campground
- High Creek Campground
Track Johnson 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 Johnson
Where does the data for Johnson 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 Johnson.