Tolna Dam No. 1 dam
Tolna Dam No. 1
Tolna Dam No. 1, also known as Johnson Dam, is a significant earth dam located in North Dakota along the Tolna Coulee. Built in 1936 by WRD, this local government-owned structure serves primarily for recreational purposes, offering a serene retreat for water resource and climate enthusiasts. With a height of 30 feet and a length of 520 feet, the dam has a storage capacity of 3080 acre-feet and covers a surface area of 166.3 acres.
Managed by the North Dakota State Water Commission, Tolna Dam No. 1 has a spillway width of 75 feet and is equipped with a single valve outlet gate for controlled water release. Despite being categorized with a "Significant" hazard potential, the dam's condition assessment is currently "Not Rated," emphasizing the need for regular inspections and maintenance. The dam's risk assessment is classified as "Moderate (3)," highlighting the importance of effective risk management measures to ensure the safety and sustainability of the structure for the surrounding community and ecosystem.
With its historical significance and natural beauty, Tolna Dam No. 1 stands as a valuable resource for both recreation and water management in the region. As climate change continues to pose challenges to water resources, the maintenance and regulation of dams like Tolna Dam No. 1 become increasingly crucial in safeguarding against potential hazards and optimizing the benefits of these vital structures for future generations of water resource and climate enthusiasts.
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 Tolna Dam No. 1 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Sheyenne River Nr Warwick | 260 cfs | → |
| James River Nr Grace City | 30 cfs | → |
| Sheyenne River Nr Cooperstown | 596 cfs | → |
| James River Above Arrowwood Lake Nr Kensal | 36 cfs | → |
| Edmore Coulee Trib Nr Webster | 36 cfs | → |
| Edmore Coulee Nr Edmore | 23 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Tolna Dam No. 1.
Boat launches
Campgrounds
Track Tolna Dam No. 1 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 Tolna Dam No. 1
Where does the data for Tolna Dam No. 1 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 Tolna Dam No. 1.