Shamrock Lake Reservoir Report

Last Updated: December 6, 2025

Shamrock Lake in Rusk, Wisconsin, is a private reservoir managed by the USDA NRCS for irrigation and recreation purposes.


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Summary

Built in 1961, this earth dam has a height of 10 feet and a length of 250 feet, with a storage capacity of 370 acre-feet. The reservoir covers a surface area of 56 acres and is fed by Shamrock Creek, showcasing a scenic natural setting for water resource and climate enthusiasts to enjoy.

With a low hazard potential and a moderate risk assessment, Shamrock Lake is regulated by the Wisconsin Department of Natural Resources, ensuring that it meets state permitting, inspection, and enforcement requirements. Despite not being rated for its condition assessment, the reservoir remains a popular destination for fishing, boating, and other recreational activities. Its uncontrolled spillway and maximum discharge capacity of 150 cubic feet per second add to the lake's appeal for water enthusiasts seeking to explore and appreciate its environmental significance.

Located in a picturesque rural area with easy access for visitors, Shamrock Lake provides a tranquil escape for those interested in water resources and climate studies. The reservoir's history, design, and management by the Natural Resources Conservation Service offer valuable insights into sustainable water usage and conservation practices. Whether for irrigation or leisure, Shamrock Lake serves as a vital resource for the local community and as a fascinating subject for enthusiasts seeking to understand the intersection of water management and environmental stewardship.

Year Completed

1961

Dam Length

250

Dam Height

10

River Or Stream

Shamrock Creek

Primary Dam Type

Earth

Surface Area

56

Hydraulic Height

4

Drainage Area

4

Nid Storage

370

Structural Height

10

Hazard Potential

Low

Nid Height

10
       
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.