Geist Reservoir Dam
Geist Reservoir Dam is a dam located in Marion County, Indiana, built in 1944. It carries a High hazard potential classification and has a fair condition assessment.
About Geist Reservoir Dam
The primary purpose of Geist Reservoir Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is public utility-owned. It impounds the Fall Creek.
The dam stands 44 feet tall and stretches 1,400 feet across, creates a reservoir covering 1,687 acres, has a maximum storage capacity of 60,000 acre-feet, and collects water from a drainage area of 215 square miles. Completed in 1944, the structure is well-established, with more than 75 years of service.
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. An emergency action plan is in place for this dam. The most recent inspection on record was 08/26/2020.
At 44 feet, this dam is taller than 90% of dams nationwide.
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 Indiana 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 | Indiana |
| County | Marion |
| River/Stream | Fall Creek |
| Coordinates | 39.90727, -85.98513 |
Physical Characteristics
| NID Height | 44 ft |
| Dam Height | 44 ft |
| Dam Length | 1,400 ft |
| Year Completed | 1944 (82 years old) |
Storage & Hydraulics
| NID Storage | 60,000 acre-ft |
| Max Storage | 60,000 acre-ft |
| Normal Storage | 21,180 acre-ft |
| Surface Area | 1,687 acres |
| Drainage Area | 215 sq mi |
| Max Discharge | 99,890 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 08/26/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IN00356 |
| Federal ID | IN00356 |
| More Info | State Dam Safety Program |