Johnston Dam
Johnston Dam is an earth dam located in Marion County, Iowa, built in 1973. It carries a Low hazard potential classification.
About Johnston Dam
The primary purpose of Johnston Dam is fire protection, stock, or small fish pond. The dam maintains a small impoundment used for fire suppression, livestock watering, or as a fish pond. The dam is owned by Joseph M Johnston (private). It impounds the Tr-ballard Creek near Red Rock Reservoir.
The dam stands 36 feet tall and stretches 320 feet across, creates a reservoir covering 5 acres, has a maximum storage capacity of 75 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1973, the structure is well into its service life at over 50 years old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. The most recent inspection on record was 03/05/1992. That was over 34 years ago.
At 36 feet, this dam is taller than 83% of dams nationwide.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Iowa |
| County | Marion |
| Nearest City | Red Rock Reservoir |
| River/Stream | Tr-ballard Creek |
| Coordinates | 41.39270, -93.19090 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 36 ft |
| Dam Height | 36 ft |
| Dam Length | 320 ft |
| Year Completed | 1973 (53 years old) |
Storage & Hydraulics
| NID Storage | 75 acre-ft |
| Max Storage | 75 acre-ft |
| Normal Storage | 47 acre-ft |
| Surface Area | 5 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Fire Protection, Stock, Or Small Fish Pond |
| Owner | Joseph M Johnston |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not Rated |
| Last Inspection | 03/05/1992 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA01642 |
| Federal ID | IA01642 |
| More Info | State Dam Safety Program |