Saint Croix Reservoir Report

Last Updated: December 5, 2025

Saint Croix, located in Riverside, Wisconsin, is a gravity dam primarily used for recreation purposes.


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Summary

Completed in 1854, this structure stands at 15 feet tall with a hydraulic height of 8 feet and a structural height of 15 feet. It has a length of 2940 feet and a maximum storage capacity of 18,000 acre-feet. The dam sits on the Saint Croix River and has a drainage area of 282 square miles, with a maximum discharge of 8175 cubic feet per second.

Despite being classified as having a low hazard potential and fair condition assessment, Saint Croix poses a very high risk due to its age and the potential consequences in the event of a failure. The dam underwent modifications in 1936 and is regulated by the Wisconsin Department of Natural Resources (WIDNR). The last inspection was conducted in September 2013, with a recommended inspection frequency of 10 years. Emergency action plans are in place, but there is room for improvement in terms of risk management measures and adherence to guidelines.

Water resource and climate enthusiasts will be intrigued by Saint Croix's historical significance, structural characteristics, and risk profile. The dam's location, design, and management provide valuable insights into the challenges and opportunities associated with maintaining aging infrastructure in the face of evolving climate conditions. As a key recreational asset in the area, Saint Croix serves as a reminder of the importance of proactive monitoring, maintenance, and emergency preparedness to ensure the safety and sustainability of water resources in Wisconsin.

Years Modified

1936 - Other

Year Completed

1854

Dam Length

2940

Dam Height

15

River Or Stream

SAINT CROIX

Primary Dam Type

Gravity

Surface Area

1913

Hydraulic Height

8

Drainage Area

282

Nid Storage

18000

Structural Height

15

Hazard Potential

Low

Nid Height

15
       
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.