The Onion River Watershed covers about 100 square miles. The Onion River flows southerly for about half its length before turning northward, entering the Sheboygan River in Rochester Park in the City of Sheboygan Falls. Belgium Creek is the only major tributary to the Onion River. There are two dams on the Onion River, which form the Waldo and Hingham impoundments.
The headwaters of the Onion River are a trout stream downstream to the top of the pool formed by the Waldo dam. The headwaters, including Ben Nutt Creek and Mill Creek, have been adversely impacted by private fish ponds on major spring sources. WDNR recently purchased property in the headwaters of Ben Nutt Creek upstream of County Highway ZZ in the Town of Plymouth. This was the site of an old fish farm and the stream had been diverted into a pond and then impounded. This cold water reach is being restored and is expected to provide important spawning and rearing habitat for brook trout.
Population, Land Use
Land use in the watershed is primarily agricultural. The entire Village of Waldo, most of the Village of Belgium, and small portions of the Village of Cedar Grove and the City of Sheboygan Falls comprise the urban areas of the watershed.
The Onion River Wateshed is located primarily within the Central Lake Michigan Coastal Ecological Landscape which stretches from southern Door County west across Green Bay to the Wolf River drainage, then southward in a narrowing strip along the Lake Michigan shore to central Milwaukee County. Owing to the influence of Lake Michigan in the eastern part of this landscape, summers there are cooler, winters warmer, and precipitation levels greater than at locations farther inland. Dolomites and shales underlie the glacial deposits that blanket virtually all of the Central Lake Michigan Coastal Ecological Landscape. The dolomite Niagara Escarpment is the major bedrock feature, running across the entire landscape from northeast to southwest. Series of dolomite cliffs provide critical habitat for rare terrestrial snails, bats, and specialized plants. The primary glacial landforms are ground moraine, outwash, and lakeplain. The topography is generally rolling where the surface is underlain by ground moraine, variable over areas of outwash, and nearly level where lacustrine deposits are present. Important soils include clays, loams, sands, and gravels. Certain landforms, such as sand spits, clay bluffs, beach and dune complexes, and ridge and swale systems, are associated only with the shorelines of Lake Michigan and Green Bay.
Historically, most of this landscape was vegetated with mesic hardwood forest composed primarily of sugar maple, basswood, and beech. Hemlock and white pine were locally important, but hemlock was generally restricted to cool moist sites near Lake Michigan. Areas of poorly drained glacial lakeplain supported wet forests of tamarack, white cedar, black ash, red maple, and elm, while the Wolf and Embarrass Rivers flowed through extensive floodplain forests of silver maple, green ash, and swamp white oak. Emergent marshes and wet meadows were common in and adjacent to lower Green Bay, while Lake Michigan shoreline areas featured beaches, dunes, interdunal wetlands, marshes, and highly diverse ridge and swale vegetation. Small patches of prairie and oak savanna were present in the southwestern portion of this landscape.
River and Stream QualityAll Waters in Watershed
Water quality in the Onion River Watershed ranges from excellent to good in the headwater areas to fair to poor in the lower sections. Sources of pollution degrading stream water quality are agricultural and urban runoff, and point source discharges. Excessive sedimentation and channelization limit stream habitat quality. Heavy metal and polycyclic aromatic hydrocarbon (PAHs) contamination is found in the sediments in the East Branch of Belgium Creek. Impoundment of headwater areas for fish hatcheries negatively impacts water quality, trout and other aquatic life.
The Onion River Watershed was one of the very first watersheds targeted under the Nonpoint Source Water Pollution Abatement (Priority Watershed) Program. A follow up report found that the watershed continues to be affected by nonpoint pollution sources. The upstream reaches (above the Village of Waldo) continue to exhibit excellent to good water quality, while the downstream reaches continue to be heavily affected by agricultural runoff.
Date 2001 Watershed Trout StreamsWatershed Outstanding & Exceptional Resources
Lakes and Impoundments
Impaired WatersList of Impaired Waters
Monitor Un. River (52300) for TP
2018 TP data exceeds criteria with 5 of 6 samples. Please review.
Do not list. Issue with sampling location not representative of tributary.
City of Sheboygan Stormwater Management Plan Update
This project is an installation of nonpoint source best management practices to contribute to the restoration of Wisconsin?s waters and was funded by the 319 grant. Storm water planning activities will be undertaken by the municipality and will result in the following products: updated storm water management plan for the entire developed urban area; and an updated storm water management plan for new development.
City of Cedarburg TMDL Storm Water Control Practice Eval
Storm water planning activities will be undertaken by the municipality and will result in the following products: updated storm water management plan for the entire developed urban area; and an updated storm water management plan for new development.
City of Plymouth Stormwater Planning
This project is an installation of nonpoint source best management practices to contribute to the restoration of Wisconsin?s waters and was funded by the 319 grant. Storm water planning activities will be undertaken by the municipality and will result in the following products: new construction erosion control ordinance; new low impact development/conservation subdivision ordinance; new storm water ordinance for new development and re-development; other new ordinances that affect runoff from the developed urban area; and development and implementation of a new financing mechanism for funding the storm water program; and a new storm water management plan for the entire developed urban area.
Cedarburg City Wide Storm Water Quality Mgmt Plan Update
Storm water planning activities will be undertaken by the municipality and will result in the following products: updated construction erosion control ordinance, updated storm water ordinance for new development and re-development, updated ordinances that affect runoff from the developed urban area, updated feasibility analysis of alternative funding mechanisms, updated storm water management plan for the developed urban area, and updated storm water management plan for new development.
Watershed History Note
Belgium and Waldo are two villages within the Onion River watershed. The Village of Belgium was originally populated by immigrants from Luxembourg, who were employed at a limestone quarry on the Lake Michigan shore, east of the village. A whole company town existed along the shore of Lake Michigan and the remains of the pier at which ships loaded can still be seen. Where the quarry once operated in the early 1900s, today there is a serene lake and hikers visiting Harrington Beach State Park can follow a nature trail around it.
Waldo, like about a half dozen other communities in the county, is the story of two separate towns that merged; one was Waldo and the other the Village of Onion River. Onion River was originally just a post office located along the river by the same name. Government surveyors had discovered quantities of wild onions growing along the stream and so named the area accordingly. The development of Onion River was based on the water power supplied by the river. However, with the spread of the railroad transportation network, waterpower declined in importance and Waldo with its railroad eventually took in Onion River.
The Village of Waldo was born when the Milwaukee and Northern Railroad was built and a depot situated in the east central part of the Town of Lyndon. The settlement which developed around the depot was known as Lyndon Station for a few years, but because there was another town by the same name in Juneau County, a new name had to be chosen. The town, an offspring of the railroad, named itself after the president of the Railroad, O.H. Waldo.