Preston Twp 21 Reservoir Report

Reservoir Report

Minnesota

Nearby: Leslie Helickson Detention Carimona Detention

Last Updated: December 5, 2025

Preston Twp 21 is a privately owned rockfill dam located in Fillmore County, Minnesota, specifically in the city of Preston.

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Summary

This dam serves the primary purpose of flood risk reduction along the Partridge Creek-TR river or stream. With a height of 28.6 feet and a storage capacity of 41.3 acre-feet, Preston Twp 21 plays a vital role in managing water levels and protecting the surrounding area from potential flooding events.

Managed by the Minnesota Department of Natural Resources, Preston Twp 21 is regulated, inspected, and enforced to ensure its structural integrity and functionality. Despite its low hazard potential, this dam has not been rated for its condition assessment. The last inspection was conducted in May 2018, with a scheduled frequency of every 8 years. While there are no emergency action plans currently in place, Preston Twp 21 continues to provide essential flood protection for the community and the environment, highlighting the importance of water resource management and climate resilience in the region.

As an integral part of the St. Paul District within the US Army Corps of Engineers, Preston Twp 21 stands as a significant infrastructure for flood risk reduction in the area. Although there is limited information on the dam's construction history and modifications, its presence and purpose underscore the ongoing efforts to safeguard communities and natural resources from potential water-related disasters. With its strategic location and operational capabilities, Preston Twp 21 remains a key asset for water resource and climate enthusiasts seeking to understand and appreciate the importance of sustainable water management practices in Minnesota.

Dam Length	410
Dam Height	28.6
River Or Stream	PARTRIDGE CREEK-TR
Primary Dam Type	Rockfill
Surface Area	2
Drainage Area	0.33
Nid Storage	41.3
Hazard Potential	Low
Foundations	Unlisted/Unknown
Nid Height	29

Explore Interactive Map

PRESTON TWP 21

Reservoir Report • Water Levels • Weather Forecast

December 5, 2025

Dam_Length	410
Dam_Height	28.6
River_Or_Stream	PARTRIDGE CREEK-TR
Primary_Dam_Type	Rockfill
Surface_Area	2
Drainage_Area	0.33
Nid_Storage	41.3
Hazard_Potential	Low
Foundations	Unlisted/Unknown
Nid_Height	29

Seasonal Comparison

Weather Forecast

Nearby Streamflow Levels

Root River Near Pilot Mound 303.0cfs	303cfs
Upper Iowa River At Bluffton 264.0cfs	264cfs
Upper Iowa River At Decorah 137.0cfs	137cfs
South Fork Root River Near Houston 209.0cfs	209cfs
Root River Near Houston 472.0cfs	472cfs
Turkey River At Spillville 78.2cfs	78cfs

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.