South Branch Root River Watershed Project
Background and Information

The South Branch Root River Watershed Project had its beginnings in 1998 when a $61,500 Clean Water Partnership grant from the MN Pollution Control Agency was awarded to the project to do a Phase I Diagnostic Study. The Phase I study included:

That study concluded in 2002, and the information was used to develop an implementation plan to address the sources of water pollution. The water quality monitoring results showed that this segment of the South Branch of the Root River is impaired for recreational use due to elevated levels of fecal coliform bacteria. The river is also impaired for sustaining aquatic life due to excess turbidity caused by sediments entering the river due to soil erosion. This segment of the river was placed on the state’s impaired waters list submitted to the U.S. Environmental Protection Agency in 2004.

In 2004, the project was awarded a 319 Implementation Grant for $299,420 as well as Clean Water Partnership Loan funds of $300,000 for upgrading septic systems and milkhouse waste systems. Implementation began in 2005 with funding for several landowner financial assistance programs to encourage adoption of Best Management Practices (BMPs) aimed at reducing bacteria and sediment in the river and its tributaries.

About the Watershed
The project area begins in the headwaters of the South Branch of the Root River west of Forestville/Mystery Cave State Park in southeastern Minnesota. The 74,330-acre project area lies in western Fillmore County in Bloomfield, Forestville, York and Beaver townships, and in eastern Mower County in Clayton and Bennington townships. The Mower County portion comprises 15,687 acres (21%) of the project area.

This watershed was chosen for a pilot watershed project for several reasons:

Four minor watersheds drain to the South Branch within the project area: Judicial Ditch #1 (11,000 acres) in Mower County and Etna Creek (4,406 acres), Forestville Creek (10,873 acres), and Canfield Creek (18,402 acres) in Fillmore County. The remaining 34,290 acres drain directly to the South Branch. The project area extends from the headwaters downstream just past the confluence with Forestville Creek. Downstream from the project area, the South Branch of the Root River extends about 30 miles to the confluence with the North Branch of the Root near Lanesboro. The entire South Branch watershed is approximately 183,600 acres.

The South Branch originates as a warm water stream but changes to a cold water stream after sinking underground near Mystery Cave and re-emerging three miles downstream at Seven Springs. Downstream from Seven Springs, the main stem of the South Branch is managed by the DNR for brown trout. The South Branch, Forestville Creek, Canfield Creek and Etna Creek are prime trout streams noted for their excellent fishery.

Land Use
Almost the entire project area is rural, and agriculture is the major land use. Over 80 percent of the land in the project area is cultivated with the primary crops being corn and soybeans. The remaining 20 percent is almost evenly divided between wooded areas or grasslands. (See the Land Use map in the Map/Picture Gallery) Ostrander (population 212), in Fillmore County, is the only incorporated city in the project area. Ostrander has 100 households served by a municipal well and a municipal wastewater treatment system, which was upgraded in 2003. Cherry Grove, Etna, and York are unincorporated villages located in Fillmore County. All residences in these villages have private wells and individual sewage treatment systems (ISTS) as do residences in the rest of the rural area. Cherry Grove does have a non-community transient public water supply well which serves a church and community center plus a few homes. The total rural population in the project area is estimated to be 1,200 in approximately 450 households. (See the Rural Households map in the Map/Picture Gallery)

Karst
The project area includes some of the best examples of karst topography in the upper Midwest. Karst features, such as caves, sinkholes, springs, blind valleys, disappearing and losing streams, and karst windows, form when slightly acidic natural waters dissolve fractured carbonate bedrock. Carbonate rock formations closest to the land’s surface in the project area are especially susceptible to solution activity. Karst features create complicated interconnections between surface water and ground water. Where soils are thin over the bedrock, karst aquifers are particularly vulnerable to contamination. Water entering a sinkhole bypasses the natural soil filtration process and becomes part of the ground water system, sometimes within a matter of minutes. Surface contaminants carried with the water are immediately introduced into the ground water. The highly dissolved cracks and fissures in the bedrock allow the water to move quickly through the subsurface. Dye trace studies have shown ground water travel times of a mile or more per day. For these reasons, surficial karst aquifers are extremely susceptible to contamination, and contaminants can move quickly through the system. In general, areas with 50 feet or more of overburden over the bedrock are considered less prone to sinkhole development.

Water entering sinkholes or stream sinks or sieves, and any surface contaminants that it carries, can discharge at springs miles from where it entered the ground. Water from springs is often used for livestock watering and fisheries. Dye tracing will continue with the 319 Implementation Project to delineate springsheds in the watershed. Many of the springs are important to maintaining cold water streams. Etna Creek, Canfield Creek, Forestville Creek and the main stem of the South Branch downstream of Mystery Cave are considered some of the best trout streams in the state and the Midwest and are managed by the DNR.

	(Left)Moth Spring is a large resurgent spring, which with the smaller Grabau Spring across the valley, contributes most of the flow at the headwaters of Forestville Creek, one of the premier trout streams in the state. Springs range in size from small seeps that produce less than one gallon per minute (gpm) to ones that produce up to 90,000 gpm.

Four blind valleys are found in the project area. York Blind Valley is the largest blind valley in Fillmore County drains about 10 square miles of the upper Canfield Creek watershed. Although the perennial portion of Canfield Creek is a tributary of the South Branch, the water sinking underground in the blind valley is “pirated” to Odessa Springs, a spring located 10 miles southeast that discharges into the Upper Iowa River, crossing one major watershed divide and several smaller drainages. There are other examples in the project area where sinkholes outside of the watershed boundary are connected through subsurface conduits to springs within the watershed illustrating the complicated relationship between surface water and ground water in karst. Fairview Blind Valley and Lefevere Blind Valley are the second and third largest blind valleys in Fillmore County, respectively. Both are found in the upper portion of Forestville Creek watershed. All surface flow from about 6 square miles of the headwaters area is pirated by Fairview Blind Valley traveling underground to Moth and Grabau Springs, which form Forestville Creek. The Cherry Grove Blind Valley unit, located just southeast of Cherry Grove, was acquired by the DNR as a Scientific and Natural Area (SNA) in 2000. The property owners had applied for a permit to quarry the limestone on the property, but adjacent landowners opposed the permit citing ground water concerns. The owners then opted to take a DNR offer to acquire the property as an SNA. The 40-acre parcel is known for its high concentration of sinkholes. Dye trace studies have shown a connection between the sinkholes on the property and Big Spring, which is the resurgence of Canfield Creek.

Mystery Cave is the longest cave in Minnesota and has several unusual formations unique to caves in this region. The cave is an important hibernaculum for four species of bats, and a number of insects have been documented, including cave crickets and two species of springtails, the only known site in Minnesota for both species. Forestville/Mystery Cave State Park was established in 1963. The abandoned town of Forestville serves as the namesake for the park and is also a state historic site.

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