Upper Sugar River watershed (SP15)

The Upper Sugar River watershed lies in southwestern Dane County. The only permitted wastewater treatment facility discharging to the stream is in Verona, although a portion of the southwest side of Madison is also in the watershed. The area around Verona and Madison is experiencing rapid urban development. This puts pressure on both surface water and groundwater resources in the watershed.

A major water resource concern is the diversion of groundwater from the Sugar River basin to the Lower Rock River basin. This is the result of the city of Madison groundwater pumpage on the city's southwest side for public water supply and subsequent treatment of wastewater at Madison Metropolitan Sewerage District Nine Springs facility.

Continued or increased groundwater diversion by Madison and Verona and the eventual connection of Verona to the Madison Metropolitan Sewerage District may lead to the reduction of base flow in the Sugar River and Badger Mill Creek, affecting water quality and in-stream habitat (DCRPC, 1993⁷). A regional groundwater study is underway to try to determine what effect groundwater diversion may actually be on base flow.

The portion of the watershed above Riley was part of a U.S. Soil Conservation Service P.L. 566 watershed plan, which began in 1981. The goals of the plan were to provide watershed protection, improve water quality and enhance fish and wildlife habitat (DCRPC, 1981⁸). An evaluation of the project, Upper Sugar River watershed Plan Evaluation report, is available through the Dane County Land Conservation Department (Barthel, 1990).

Badger Mill Creek

Badger Mill Creek is a tributary to the Sugar River near Verona. The perennial reach of the stream begins in a wetland west of Goose Pond between Madison and Verona. At one time, water quality in the creek was rated poor due to inadequately treated municipal and industrial wastewater discharged to it. Since 1978, these discharges have been eliminated or diverted. As a result, water quality and in-stream habitat have improved.

The stream has been reclassified from supporting a limited forage fishery to supporting a warmwater forage fishery (Marshall, 1989¹⁴). Trout have been found in the stream below Verona. The Dane County Conservation League has sponsored extensive streambank fencing and protection projects on the creek (Wells, 1994). It has been proposed to discharge treated effluent from a closed Dane County landfill to the creek.

The creek's drainage area includes much of the southwest side of Madison as well as most of Verona. Urban runoff poses a significant threat to Badger Mill Creek. Rapid urban development in Madison and Verona, coupled with poor or non-existent construction site erosion control and stormwater management threatens water quality and habitat of the creek and the wetlands associated with it (Wisconsin DNR, 1992-93¹).

Urban growth has already increased peak stormwater runoff and flows from impervious surfaces. Increased amounts of sediment and other pollutants entering Badger Mill Creek and ultimately the Sugar River can be expected if Madison, Verona and Dane County do not take appropriate action. If no action is taken, in 20 years Badger Mill Creek could become nothing more than a stormwater conduit to the Sugar River for the cities of Madison and Verona. Stormwater planning for this area should include addressing the reduction of peak runoff rates from existing developed areas as well as keeping runoff rates from future developments at the pre-development runoff rate.

Henry Creek

Henry Creek is a very small spring-fed tributary to the Sugar River near the community of Basco. The creek likely has good water quality and fair in-stream habitat (Marshall, 1988), with the potential to support trout (Marshall, 1988), although siltation and the level of streamflow are problems. The stream runs through a small wetland that is part of the larger Sugar River wetland complex. These wetlands serve an important function as a buffer for the Sugar River, as well as for wildlife, fisheries and aesthetic values.

Schlapbach Creek

Schlapbach Creek rises near the northeast corner of the village of Mount Horeb and flows easterly to the Sugar River. The stream is spring-fed and has good water quality based on biotic index ratings (Marshall, 1988). In-stream habitat rates only fair due to sedimentation from intense grazing of streambanks and runoff from croplands. If these sources of polluted runoff were controlled, the stream has the potential to be a trout stream (Marshall, 1988). Schlapbach Creek has been nominated for Exceptional Resource Water (ERW) status under the state's antidegradation rules in NR 102 and NR 207.

Sugar River

The reach of the Sugar River in this watershed runs from the dam at Belleville to the headwaters of the river northeast of Mt. Horeb. The Belleville dam and one at Paoli impede fish migration. Water quality in this reach of the river has gradually improved (Wisconsin DNR, 1992-93,¹). The stream's classification was recently upgraded to supporting a coldwater sport fishery from the headwaters to the Frenchtown Road bridge above Lake Belle View (Marshall and Stewart, 1993).

Water quality in the river is considered generally good. High fecal coliform levels in the stream are a concern (DCRPC, 1992,⁶). Urban and agricultural sources of polluted runoff are likely sources of water quality problems. Runoff from farm fields, streets and parking lots, construction sites and barnyards, intense grazing adjacent to the stream and streambank erosion are adding sediments and pollutants to the stream and degrading habitat and water quality.

Large wetland complexes exist adjacent to the Sugar River. Other wetland areas have been drained and put into agricultural production. Wetland drainage and stream straightening in some locations have also degraded habitat and water quality.

Urban sources of polluted runoff do not yet appear to be harming water quality or in-stream habitat of the Sugar River. However, threats to water quality increase with continued urban growth in the Madison-Verona area. The U.S. Highway 18-151 Verona bypass and reconstruction, coupled with the addition of Verona to the Madison Metropolitan Sewerage District, likely will accelerate urban growth in this area. This could lead to increased water quality problems unless appropriate and proper land use planning measures and ordinances are enacted and enforced.

Groundwater diversion, mentioned above, also poses a threat to water quality and in-stream and riparian habitat. Long-term, cumulative effects of urbanization on water quality and in-stream habitat of the upper reaches of the Sugar River are a major concern of DNR staff. The tools and responsibility for addressing long-term management of Sugar River water quality rests with Dane County and the municipalities in the watershed. It is conceivable that if the present rapid urban growth in this area continues unchecked, water quality, fisheries and in-stream habitat may be significantly degraded as a result of lowered groundwater base flow to the river.

The entire stretch of the Sugar River within this watershed is classified as Exceptional Resource Waters (ERW) under the state's antidegradation rules, NR 102 and NR 207.

Lake Belle View

Lake Belle View is a shallow impoundment of the Sugar River at the village of Belleville in southern Dane County. The lake suffers from the water quality problems usually associated with impoundments, including sedimentation, turbidity, excessive rooted aquatic plants and attached algae, free-floating blue-green algae, water level fluctuations, fish winterkills and rough fish (Marshall, 1988¹²).

Lake Belle View was drawn down in 1992 for dam repair. A proposal was made to dredge the lake in 1989, but the costs were too high. Southern District staff concluded at that time that dredging would not be a long-term solution to the lake's water quality problems. The best-case scenario for the millpond at Belleville is that the water quality of the lake would only be as good as that of the Sugar River (Wisconsin DNR, 1992-93¹). The best-case scenario for the Sugar River at Belleville is that the dam is operated as "run of the river" dam, allowing much of the existing millpond to become a riverine wetland complex.

Morse Pond

Morse Pond is a small, shallow pothole pond on the edge of the Driftless Area west of Madison. The pond is unique in that it has a large bed of lotus (Nelumbo lutea) not found on many other waterbodies in the Sugar-Pecatonica basin. Construction of the University of Wisconsin golf course resulted in excessive sediment entering the pond during storm runoff (Wisconsin DNR, 1992-93¹). Completion of the golf course has reduced the sedimentation problem, but the lotus beds are threatened by nutrients and herbicides washing off the golf course into the pond.