Decatur Lake – Sugar Creek

Quick Facts

Hydrologic Unit Code (HUC-12): 070900040605

Area: 23.4 square miles (14,961 acres); 8% of Lower Sugar River Watershed/2011

Counties: Green County/Decatur, Albany, Mt Pleasant and Spring Grove Townships

Municipalities: City of Brodhead [population 3202 (7/1/15)], Village of Albany [population 1202 (7/1/15)]

Primary Land Uses: Agriculture (cropland 47.8%, pasture/hay 19.9% of landcover/2011)

Points of Interest: Sugar River, Village of Albany, Albany Lake (aka Lake Winnetka), City of Brodhead, Decatur Lake, Pearl Island Recreational Corridor (includes Mill Race), Brodhead Historical Society Depot Museum, Sugar River State TrailRustic Road No. 27 (Park Road),  Albany Wildlife Area, State Natural Areas: Ward/Swartz Decatur WoodsAbraham's Woods and Muralt Bluff Prairie.

Water Quality: Exceptional Resource Water (ERW); Impaired - 303d listed for phosphorus. See section Did You Know? below.   

At a Glance

  • The Sugar River runs roughly midway through this subwatershed as it flows from Albany to the north down through and past Brodhead at the southern end of the subwatershed's boundary. Within the subwatershed, the Sugar River is dammed at two locations, one in Albany forming Albany Lake (102 acres) and one northwest of Brodhead forming Decatur Lake (109 acres). Locally, Albany Lake is also known as Lake Winnetka. Both of these impounded lakes are shallow and heavily silted due primarily to agriculture runoff. 
  • The extreme eastern portion of Albany Wildlife Area just west of Albany exists within this subwatershed and extends west into the Middle Sugar River Watershed along the Little Sugar River towards Monticello.
  • Two State Natural Areas reside within this subwatershed: Ward/Swartz Decatur Woods and Abraham's Woods. Muralt Bluff Prairie is just outside the subwatershed northwest boundary.
  • Decatur Lake-Sugar Creek Subwatershed is one of three subwatersheds draining into Decatur Lake, the other two being Searles Creek and Norwegian Creek.

Learn More

The Brodhead dam has been in existence in some form since the mid-1800s (1847-48). It was originally built to establish a millpond (today known as Decatur Lake) to power a sawmill, and by 1849 it was also powering a grist and flour mill. The small settlement of Decatur grew up nearby and by 1857 had grown to some 400 strong; however, its residents and businesses alike soon abandoned their village for Brodhead in order to take advantage of the railroad established there in 1857. Construction of the 3.1 miles long Mill Race from the millpond to Brodhead began in 1858 and was in operation on May 6, 1863. The race furnished power for a flouring mill and later a foundry, several wagon shops and a plow factory. Electricity was being produced by 1886. This whole area has a rich history to explore and a good place to start is the Brodhead Historical Museum Depot and website. Today, the Mill Race and adjacent land corridor, owned by the City of Brodhead, are now known as the Pearl Island Recreational Corridor. It is being developed to provide year-round recreational opportunities to residents and visitors.

A rather fascinating piece of local history involves the de Mun trading post or cabin once situated on the west bank of the Sugar, south of the present-day dam.  Built in the fall of 1831 by Jules de Mun and abandoned less than a year later in April of 1832, there was no proof the cabin existed until an archeological expedition in 1986 -1987 led by Tom Fey and Donald Thompson found the fire-damaged site. A description of their dig discoveries and historical review of Jules de Mun were published in the Wisconsin Academy Review, June 1988 and can be accessed here. Harriet Halloran in July of 1998 published an article based on the journal article in the Brodhead Independent Register and can be viewed here.

Marsh Creek, a small spring-fed stream east of Albany flows southwest and joins the Sugar River below Albany. The Wisconsin Department of Natural Resources (WDNR) has classified this stream as a Class III trout stream.


With the presence of the Sugar River, Mill Race, two lakes, Albany Wildlife Area, a golf course and three state natural areas, recreational opportunities abound. Camping, canoeing, kayaking, tubing and fishing are all available activities for the outdoor enthusiast to pursue. A boat launch is available at Headgates Park, off of Golf Course Road in Brodhead (complete with bathroom facilities). If those activities are not appealing, try biking, walking and birding on the Sugar State River Trail which has its southern terminus in Brodhead. Within the Pearl Island Recreational Corridor in Brodhead in addition to the main biking/walking trail along the race there are also several newly created hiking trails along the river. What about picnicking? Head over to the "Corridor" which has new tables and fire pits scattered throughout.

At Sweet Minihaha and Crazy Horse Campgrounds near Albany and Brodhead respectively, camping, canoe/kayak and tube rentals are available. S&B Tubing in Albany offers tube, canoe and kayak rentals as well.

What is so appealing when you venture outdoors is what you might see on any of these outdoor pursuits in the wooded Sugar River corridor in this subwatershed. White-tailed deer, turkeys, turkey vultures, bald eagles, pileate woodpeckers as well as other woodpecker species, barred Barred Owl Google Searchowls, red foxes, hawks, mink, white pelicans, several kinds of turtles, ducks, and many song birds are but a few examples of the rich biological diversity occupying the rich complex of upland and aquatic habitats in the basin.

Try leaf peeping along Park Road in the fall. A four-mile section bracketed by County F is a designated Wisconsin Rustic Road (No. 27). The vibrant yellow color of Black Maples which are very similar but a distinct species from Sugar Maples will not disappoint. Try exploring Ward/Swartz Decatur Woods off Park Road, a 13-acre state natural area an example of a southern dry-mesic forest. In the spring many wildflowers abound here and await your discovery. Unfortunately, the invasive plant, garlic mustard is also found in these woods which has an uncanny capacity to crowd out our native wildflowers. 

Two other state natural areas, Muralt Bluff Prairie and Abraham's Woods beckon, but to visit the latter requires access permission from UW-Madison Arboretum [(608)263-7344]. 

Did You Know?

The entire length (81) miles of the Sugar River in Wisconsin is designated as an Exceptional Resource Water (ERW). Yet sections are impaired for excessive phosphorus due to point source discharges by wastewater treatment facility (e.g. City of Brodhead) and non-point source runoff from agricultural fields and barnyards into tributary streams feeding into the river. The section of the river within the subwatershed, Decatur Lake and the Mill Race, are all impaired for phosphorus and have been placed on the WDNR's 303d impaired waters list.

Why is "Sugar Creek" part of the subwatershed's name and not "Sugar River" as the river figures dominantly in this subwatershed, and nowhere within is there a Sugar Creek? As it turns out Sugar Creek and Sugar River are one and the same. On early maps, the river was referred to as Sugar Creek. Mystery solved!

For a printable PDF map of Decatur Lake - Sugar Creek Subwatershed click here.


2011 National Landcover Database:

Brodhead Free Press, Vol. 6, No’s. 30 (10/29/14), 31(11/5/2014), 32 (11/12/2014), Looking  back at the history of the Brodhead Mill Race by Carol Gombar