Oaknoll Dam
Oaknoll Dam is an earth dam located in Johnson County, Iowa, built in 1994. It carries a High hazard potential classification and has a fair condition assessment.
About Oaknoll Dam
The primary purpose of Oaknoll 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 Oaknoll West Llc (private). It impounds the Tr- Iowa River near Iowa City.
The dam stands 25 feet tall and stretches 545 feet across, creates a reservoir covering 5 acres, has a maximum storage capacity of 95 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1994, the structure is 32 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 07/15/2024.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Iowa dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Iowa |
| County | Johnson |
| Nearest City | Iowa City |
| River/Stream | Tr- Iowa River |
| Coordinates | 41.63660, -91.57580 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 25 ft |
| Dam Height | 25 ft |
| Dam Length | 545 ft |
| Year Completed | 1994 (32 years old) |
Storage & Hydraulics
| NID Storage | 95 acre-ft |
| Max Storage | 95 acre-ft |
| Normal Storage | 43 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 | Oaknoll West LLC |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 07/15/2024 |
| Emergency Action Plan | No |
Identifiers
| NID ID | IA02848 |
| Federal ID | IA02848 |
| More Info | State Dam Safety Program |