Tremper Dam

Tremper Dam
Name	Tremper Dam
Location	Portage County, Wisconsin, Kronenwetter, Wisconsin
Country	United States
Status	Operational
Construction began	1960s
Opening	1970s
Owner	Wisconsin Department of Natural Resources
Dam type	Earthfill
Height	30 ft
Length	1,200 ft
Reservoir	Lake Arbutus
Capacity	5,000 acre-feet

Tremper Dam is a small earthfill impoundment located in Portage County, Wisconsin, within the watershed of the Wisconsin River. The facility regulates local streamflow, provides limited flood control, and forms a recreational reservoir managed by the Wisconsin Department of Natural Resources. It sits near the community of Kronenwetter and is part of regional water infrastructure alongside facilities such as Red Cedar Lake Dam and Chippewa Flowage.

History

The project emerged during postwar regional development initiatives influenced by planning discussions involving the Army Corps of Engineers, state agencies, and local boards in the 1950s and 1960s. Early advocacy from county supervisors aligned with conservation goals promoted by organizations like the Sierra Club and the National Audubon Society. Funding and permitting reflected federal-state coordination seen in contemporaneous projects such as Tuttle Creek Dam and Garrison Dam. Community meetings referenced precedents in the Civilian Conservation Corps era and debates echoed hearings held for the Wolf River basin. By the time construction commenced, stakeholders included the Wisconsin Department of Natural Resources, local landowners, and utilities operating near Stevens Point, Wisconsin.

Design and Construction

Designed as an earthfill embankment similar in concept to portions of Tuttle Creek Lake, the dam incorporated an impervious core, filter zones, and a stone riprap facing resembling techniques used at Fox River crossings. Engineering plans were reviewed by consulting firms experienced with projects like Kenosha Dam and informed by standards promulgated after incidents at St. Francis Dam. Construction contracts were awarded to regional contractors who had previously worked on projects for the Wisconsin Department of Transportation and the Public Works Administration legacy infrastructure. Soil testing referenced stratigraphy reports comparable to surveys done near Green Bay and utilized borrow material sourced from sites analogous to quarries serving Marathon County.

Hydrology and Reservoir

The impoundment intercepts tributaries feeding the Wisconsin River system and forms a reservoir that moderates seasonal flows similar to upstream storage at Lake DuBay. Hydrologic modeling used rainfall-runoff relationships comparable to analyses for Upper Mississippi River tributaries and relied on historic gage records from stations near Stevens Point and Waupaca. The reservoir's storage capacity supports low-flow augmentation and attenuates peak discharges during storm events like those experienced during the Great Flood of 1978 and other regional floods. Sedimentation patterns and watershed inputs have been monitored using protocols similar to studies of Fox-Wolf River Basin reservoirs.

Recreation and Public Access

The impoundment and adjacent lands provide recreational opportunities parallel to those at Lake Arrowhead (Wisconsin) and Castle Rock Lake. Visitors engage in boating, angling for species monitored by the Wisconsin Department of Natural Resources, and shoreline activities promoted by county parks departments associated with Portage County Parks. Access points are maintained in coordination with regional trail systems, akin to connections between Ice Age National Scenic Trail segments and local parklands. Nearby communities, including Marshfield, Wisconsin and Mosinee, Wisconsin, benefit from tourism and day-use amenities that mirror services offered at Rib Mountain State Park.

Environmental and Ecological Impact

Ecological assessments referenced frameworks used by the Environmental Protection Agency and state conservation programs, examining impacts on fish assemblages similar to those documented in studies of Chequamegon Bay tributaries. The impoundment altered riparian habitats and wetland extent in ways analogous to changes observed at Fox Lake (Wisconsin), prompting mitigation measures coordinated with the U.S. Fish and Wildlife Service. Invasive species concerns paralleled management responses to infestations in the Great Lakes basin, leading to outreach modeled on campaigns by University of Wisconsin–Madison extension programs and Wisconsin Department of Natural Resources aquatic invasive species initiatives.

Operations and Maintenance

Routine operations follow protocols comparable to guidance from the Army Corps of Engineers and coordination with state emergency planners in Wisconsin Emergency Management. Maintenance tasks—embankment inspections, spillway clearing, and instrumentation checks—use best practices similar to programs at La Crosse Floodwall and other midwestern hydraulic structures. Water level management is informed by seasonal forecasts produced by the National Weather Service and hydrologic data from USGS gaging stations in the region. Long-term asset management has involved periodic rehabilitation contracts like those executed for aging dams statewide under state capital improvement programs.

Incidents and Modifications

Over its operational life the facility experienced routine repairs and occasional emergency actions comparable to interventions at small dams across Wisconsin River tributaries. Modifications have included spillway upgrades influenced by post-event retrofits seen after the 2007 Midwest floods and installation of monitoring instrumentation analogous to systems deployed following investigations of failures such as Ka Loko Dam. Local response plans developed with Portage County emergency services drew on incident protocols practiced with neighboring utilities and infrastructure managers.

Category:Dams in Wisconsin