Mason Dam No. 1 (South) Reservoir Report

Last Updated: December 6, 2025

Mason Dam No.


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Summary

1 (South), also known as Old South Lake Dam, is a private earth dam located in Switzerland County, Indiana. Completed in 1975, the dam stands at a height of 29 feet and has a length of 400 feet, creating a reservoir with a storage capacity of 37 acre-feet. Situated on Indian Creek, the dam serves multiple purposes, including flood control and water storage for irrigation and recreational activities.

Despite being regulated by the Indiana Department of Natural Resources, Mason Dam No. 1 (South) has a low hazard potential and is classified as being in fair condition. The dam features an uncontrolled spillway with a width of 15 feet and has a maximum discharge capacity of 83 cubic feet per second. With a moderate risk assessment rating, the dam is subject to regular inspections every five years to ensure its structural integrity and safety.

For water resource and climate enthusiasts, Mason Dam No. 1 (South) presents an interesting case study in private dam ownership and management. With its strategic location on Indian Creek and its role in water storage and flood control, the dam offers insights into the importance of maintaining and monitoring infrastructure to mitigate risks and ensure the sustainable use of water resources in the region.

Year Completed

1975

Dam Length

400

Dam Height

29

River Or Stream

INDIAN CREEK

Primary Dam Type

Earth

Surface Area

3.3

Hydraulic Height

29

Drainage Area

0.02

Nid Storage

37

Structural Height

29

Outlet Gates

None

Hazard Potential

Low

Nid Height

29
       
Seasonal Comparison

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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.