Holly Twp 9 Reservoir Report
Nearby: Holly Twp 16 Holly 2
Last Updated: December 12, 2025
Holly Twp 9, located in Murray County, Minnesota, is a privately owned earth dam completed in 2007 for flood risk reduction on Plum Creek.
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Summary
Managed by AREA II MN RIVER BASIN PROJECTS, INC, this dam stands at 40 feet in height with a structural height of 50 feet and a total length of 400 feet. With a storage capacity of 186 acre-feet and a drainage area of 1.6 square miles, Holly Twp 9 plays a crucial role in mitigating potential flooding in the surrounding Walnut Grove area.
Despite its low hazard potential, Holly Twp 9 is subject to regular inspections by the Minnesota Department of Natural Resources, with the last assessment conducted in March 2016 deeming its condition as satisfactory. With a moderate risk assessment level of 3, the dam has not experienced any significant modifications since its completion. While the dam lacks certain features like outlet gates and locks, its uncontrolled spillway type ensures effective water discharge during periods of high flow. Overall, Holly Twp 9 serves as a vital infrastructure piece in the region's water resource management efforts.
As an essential part of the flood risk reduction infrastructure in the St. Paul District, Holly Twp 9 contributes to the overall resilience of the Plum Creek watershed. With its private ownership and state regulation, the dam is a key asset in protecting the local community from potential flooding events. By meeting state permitting, inspection, and enforcement requirements, Holly Twp 9 demonstrates a commitment to maintaining its functionality and ensuring the safety of residents in the surrounding area.
Year Completed |
2007 |
Dam Length |
400 |
Dam Height |
40 |
River Or Stream |
PLUM CREEK-TR |
Primary Dam Type |
Earth |
Drainage Area |
1.6 |
Nid Storage |
186 |
Structural Height |
50 |
Hazard Potential |
Low |
Nid Height |
50 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
Holly Twp 9