Merillan Mills dam
Merillan Mills
Merillan Mills, located in Merrillan, Wisconsin, is a gravity dam constructed in 1907 primarily for recreational purposes. The dam spans 250 feet in length and has a height of 23 feet, with a storage capacity of 170 acre-feet. Situated on Halls Creek in Jackson County, Wisconsin, the dam serves as a popular spot for outdoor enthusiasts seeking recreational activities such as boating, fishing, and wildlife observation.
Managed by the local government and regulated by the Wisconsin Department of Natural Resources (WIDNR), Merillan Mills has a low hazard potential and is assessed to be in fair condition as of May 2020. The dam's spillway type is uncontrolled, with a maximum discharge capacity of 2750 cubic feet per second. Despite its moderate risk assessment rating, the dam has not been significantly modified or updated in recent years, with its last inspection conducted in July 2016.
For water resource and climate enthusiasts, Merillan Mills offers a glimpse into the historical significance of dam infrastructure in Wisconsin, as well as the importance of balancing recreational use with environmental conservation and safety considerations. With its scenic location and relatively low hazard potential, the dam provides a valuable opportunity for outdoor recreation while highlighting the need for ongoing monitoring and maintenance to ensure its continued functionality and safety.
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.
- 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.
- 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.
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, environmental 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.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Merillan Mills -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Black River Ds St Hwy 54 @ Black River Falls | 1,560 cfs | → |
| Black River At Neillsville | 742 cfs | → |
| Black River Near Galesville | 1,230 cfs | → |
| La Crosse River At Sparta | 237 cfs | → |
| Trempealeau River At Arcadia | 657 cfs | → |
| Yellow River At Babcock | 61 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Merillan Mills.
Boat launches
- Arnold Creek -- North Arnold Creek Access
- Lake Arbutus -- Access Nr Robin Ln
- Lake Arbutus -- Access Nr Osprey Ln
- Lake Arbutus -- Access Nr Klima Rd
- Black River -- North Arbutus Boat Landing
- Mark Holmgren Memorial Landing -- Access
Campgrounds
- Gile Memorial Village
- Wildcat Mound County Park
- Russell Memorial Park
- Russell Memorial Campground
- West Arbutus County Park
- East Arbutus Camp
Fishing spots
More reservoirs
Track Merillan Mills in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Merillan Mills
Where does the data for Merillan Mills come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Low hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Merillan Mills.