Johnston Dam dam
Johnston Dam
Johnston Dam in Keosauqua, Iowa, is a private-owned earth dam completed in 2005 by USDA NRCS. With a height of 29 feet and a length of 220 feet, this dam serves the primary purpose of grade stabilization along a tributary to the Des Moines River. The dam has a storage capacity of 29 acre-feet and covers a surface area of 2 acres, with a low hazard potential and a condition assessment of "Not Rated".
Situated in Van Buren County, Iowa, Johnston Dam plays a crucial role in managing water resources and preventing erosion in the area. The dam is equipped with spillways and outlet gates to regulate water flow and ensure safety during periods of high discharge. Although the dam has not been rated for its condition, its design and construction by USDA NRCS reflect a commitment to sustainable water management practices. For water resource and climate enthusiasts, Johnston Dam stands as an example of effective infrastructure for environmental conservation and management.
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 Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Des Moines River At Keosauqua | 7,370 cfs | → |
| Fox River At Bloomfield | 7 cfs | → |
| Cedar Creek Near Oakland Mills | 55 cfs | → |
| Des Moines River At Ottumwa | 7,220 cfs | → |
| Des Moines River At St. Francisville | 6,910 cfs | → |
| Big Creek Near Mt. Pleasant | 7 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Johnston Dam.
Boat launches
- Jersey Avenue Van Buren County
- Van Buren County
- Lake Showme Drive Scotland County
- Cliffland Road Wapello County
- See Road Scotland County
- Jefferson Street Viaduct Ottumwa
Track Johnston 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 Johnston Dam
Where does the data for Johnston 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 Johnston Dam.