Grosse Reservoir Report
Nearby: Marsh Lake Nelligan Lake
Last Updated: December 8, 2025
Grosse, also known as Murphy Creek, is a private water resource located in Marinette, Wisconsin, designed by the USDA NRCS.
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Summary
This dam, completed in 1970, serves primarily for recreational purposes, with a modest height of 18 feet and a storage capacity of 80 acre-feet. The dam spans 480 feet and has a maximum discharge rate of 240 cubic feet per second. While it has a low hazard potential and fair condition assessment, it is regulated by the Wisconsin Department of Natural Resources, with regular inspections and enforcement measures in place.
Situated in the Detroit District, Grosse offers a serene escape for water and climate enthusiasts in the area. With its uncontrolled spillway type and relatively small drainage area of 2 square miles, the dam provides a peaceful setting for outdoor activities. The dam has a moderate risk assessment rating, indicating a level of caution, but overall, it remains a safe and well-maintained water resource for the community. The last inspection in June 2018 showed no major concerns, and the dam continues to be monitored to ensure its continued integrity.
Despite its private ownership, Grosse contributes to the local environment and economy by offering recreational opportunities in the heart of Marinette, Wisconsin. With its picturesque location and moderate risk profile, this dam serves as a valuable asset to the region, providing a source of enjoyment for residents and visitors alike. As climate change and water resource management become increasingly important topics, Grosse stands as a testament to the importance of sustainable and well-regulated water infrastructure in maintaining a healthy and vibrant community.
Year Completed |
1970 |
Dam Length |
480 |
Dam Height |
18 |
River Or Stream |
MURPHY CREEK |
Primary Dam Type |
Earth |
Surface Area |
8 |
Hydraulic Height |
11 |
Drainage Area |
2 |
Nid Storage |
80 |
Structural Height |
18 |
Hazard Potential |
Low |
Nid Height |
18 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Peshtigo River At Porterfield
|
498cfs |
Peshtigo River At Peshtigo
|
513cfs |
Oconto River Near Oconto
|
319cfs |
Oconto River Near Gillett
|
596cfs |
Peshtigo River Near Wabeno
|
226cfs |
Menominee River Near Mc Allister
|
2220cfs |
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.
Grosse
Murphy Lake -- Access at E Side Of Lake