Johnson Dam dam
Johnson Dam
Johnson Dam, located in Fairfield, Iowa, is a private earth dam completed in 1991 with a height of 20 feet and a length of 375 feet. The dam serves multiple purposes including fire protection and creating a stock or small fish pond. With a storage capacity of 63 acre-feet, the dam is situated on TR-Cedar Creek and is regulated by the Iowa Department of Natural Resources.
Despite its low hazard potential, Johnson Dam has a moderate risk rating of 3. The dam has not been rated for its condition assessment, and there is limited information available on emergency preparedness measures, such as the existence of an Emergency Action Plan (EAP) or updated contact information. The risk management measures and potential inundation maps for the dam are also not readily available.
Water resource and climate enthusiasts interested in Johnson Dam should note its significance in providing water for fire protection and recreational activities. The dam's location in Jefferson County, Iowa, along with its regulated status and moderate risk rating, highlight the importance of ongoing monitoring and maintenance to ensure the safety and effectiveness of this essential water infrastructure.
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 |
|---|---|---|
| Cedar Creek Near Oakland Mills | 62 cfs | → |
| Big Creek Near Mt. Pleasant | 9 cfs | → |
| Des Moines River At Keosauqua | 6,820 cfs | → |
| North Skunk River Near Sigourney | 299 cfs | → |
| Des Moines River At Ottumwa | 6,430 cfs | → |
| Fox River At Bloomfield | 7 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Johnson Dam.
Boat launches
- Dogwood Avenue Washington County
- Van Buren County
- W15 / 330th Avenue Keokuk County
- County Road V5g Keokuk County
- Jersey Avenue Van Buren County
- Cliffland Road Wapello County
Campgrounds
- Round Prairie Park
- Mac Coon Access
- Lake Darling State Park Campground
- Lake Darling State Park
- Water Works Park
- Waterworks Park - Oakland Mills Park
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.