Physical Features

Topography

The City of Thorp lies in an area of gently rolling terrain. Topographical relief ranges from approximately 1,180 feet along McGrogan Creek in the southwestern portion of the City to 1,250 feet in the northeast corner. The City experiences a gentle sloping of zero to six percent from the northeast to the southwest, while some steeper slopes of six to twelve percent are noted to the northwest and southwest, beyond the City limits.

Soils

The soils in the Thorp area have been analyzed using information provided by the Clark County Natural Resources Conservation Service (NRCS). The predominant soil types in the City and surrounding area consist of deep, nearly level to moderate sloping, moderately well-drained and somewhat poorly drained, loamy and silty soils on ground moraines.

The soils of the Thorp area have been mapped, analyzed and categorized as to their suitability for development.

Wetlands and Waterways

A wetland is any area which water is at, near, or above the surface long enough to support hydrophytic vegetation, or water-loving plants, and which has soils indicative of wet conditions. Wetlands may be seasonal or permanent and are commonly referred to as swamps, marshes, or bogs. These areas serve as groundwater recharge zones and also as a habitat for a variety of plants and animals. Wetlands act like a sieve, filtering out silts before they can enter streams and lakes. Wisconsin Wetland Inventory maps and the soil survey were used to delineate all regulated wetlands within the planning area. McGrogan Creek is the primary waterway through Thorp. It also has several associated minor wetlands. All wetlands are protected from development according to Department of Natural Resources' regulation.

McGrogan Creek runs in a generally southwesterly direction and serves as the major drainageway through the southern portion of the City. An area of varying width adjacent to McGrogan Creek is designated as a floodway for flood insurance purposes. The floodway encompasses the stream channel, floodplain, and an adjacent area determined to be inundated during a 100-year flood event. Encroachment on floodplains, such as artificial fill, reduces the flood carrying capacity, increases the flood heights of streams, and increases flood hazards in areas beyond the encroachment itself. Due to the associated risks and difficulties with development in these areas, they generally act as barriers to development. In fact, Thorp has identified McGrogan Creek as a natural area and has worked to preserve its natural setting as a link between several of the City's parks and recreation areas.

Vegetative Cover

Much of the surrounding countryside around the built-up area of Thorp is used for agricultural cropland. Trees are present in small scattered woodlots or in areas unsuited for agriculture. The Conway Park woodlands is a small hardwood woodlot within the City and is protected by being incorporated into the City's park system. There are also good shade trees in and around the residential areas of the City. Trees are important for communities as they stabilize the soil, supply natural cooling shade, improve air quality, and provide natural beauty.