Johnson Dam dam
Johnson Dam
Johnson Dam, located in Mills County, Iowa, is a privately owned structure designed by NRCS for fire protection and as a small fish pond. Completed in 2006, the earth dam stands at a height of 30 feet and spans 513 feet in length, with a storage capacity of 83 acre-feet. Situated on TR- Keg Creek, the dam serves as a crucial water resource for the surrounding area, with a normal storage capacity of 54 acre-feet and a surface area of 5.1 acres.
Managed by the Iowa DNR, Johnson Dam is regulated, permitted, inspected, and enforced by the state. Classified with a low hazard potential and a moderate risk assessment, the dam meets guidelines for emergency action plans and risk management measures. While the spillway is uncontrolled with a spillway width of 1 foot, the dam's condition assessment is currently not rated, with no recent inspection date available. Despite this, Johnson Dam remains a vital asset for water storage and conservation in the region.
For water resource and climate enthusiasts, Johnson Dam offers insights into the intersection of infrastructure, water management, and environmental stewardship. With its strategic location, design features, and regulatory oversight, the dam provides a tangible example of how private entities can contribute to sustainable water practices. As part of the broader network of dams and reservoirs in the area, Johnson Dam plays a crucial role in ensuring water security, flood protection, and habitat preservation for the local ecosystem.
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 Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Missouri River At Omaha | 29,100 cfs | → |
| West Nishnabotna River At Randolph | 693 cfs | → |
| Big Papillion Cr | 38 cfs | → |
| West Nishnabotna River At Hancock | 313 cfs | → |
| Platte R At Louisville Ne | 4,040 cfs | → |
| Weeping Water Creek At Union | 17 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Johnson Dam.
Boat launches
- Mills County
- I 29;Us 275 Mills County
- Us 34;Us 275 Mills County
- Lake Manawa State Park
- Catfish Rd Council Bluffs
- Haworth River Park
Campgrounds
- Pony Creek Co Park
- Glenwood Lake Park
- Lake Manawa State Park
- Haworth City Park - Bellevue
- Famcamp
- Offutt Afb Military
More reservoirs
Track Johnson Dam 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 Dam
Where does the data for Johnson Dam 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 Johnson Dam.