Geist Reservoir Dam Reservoir Report

Last Updated: December 14, 2025

Geist Reservoir Dam, located in Marion, Indiana, was completed in 1944 and serves as a crucial water supply source for the region.


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Summary

With a height of 44 feet and a hydraulic height of 39 feet, the dam plays a significant role in regulating the flow of Fall Creek. The reservoir has a storage capacity of 60,000 acre-feet, with a normal storage level of 21,180 acre-feet, covering a surface area of 1687.66 acres.

This earth and stone dam has a length of 1400 feet and a spillway width of 500 feet, allowing for a maximum discharge of 99,890 cubic feet per second. Despite its high hazard potential, the dam is currently assessed to be in fair condition. The dam is under state regulation and inspection, with the Indiana Department of Natural Resources overseeing its permitting, inspection, and enforcement processes.

In addition to its primary purpose of water supply, Geist Reservoir Dam also serves recreational purposes. The dam, situated in a picturesque location on the Fall Creek, not only provides a vital water resource for the community but also offers opportunities for outdoor activities and enjoyment. The dam's strategic location and structural design make it a key feature in the region's water resource management and climate resilience efforts.

Year Completed

1944

Dam Length

1400

Dam Height

44

River Or Stream

FALL CREEK

Surface Area

1687.66

Hydraulic Height

39

Drainage Area

215

Nid Storage

60000

Structural Height

44

Outlet Gates

None

Hazard Potential

High

Nid Height

44
       
Seasonal Comparison

Weather Forecast

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. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
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. Investigations and studies are necessary.
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.
Not Available
Dams for which the condition assessment is restricted to approved government users.

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, environment 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.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.