Looking for Signs of Disturbance
The first step in assessing a site's restoration potential is to determine what historical impacts have occured. Knowing how, and to what extent, your wetland is degraded is critical for determining how best to restore it to its original condition. Unfortunately many, if not most, of Wisconsin’s wetlands have been harmed by some form of human activity over the past 100 to 150 years. It is hard to find a wetland that does not have signs of disturbance, especially in urban areas of the state. Indicators of disturbance that you may observe include hydrologic alterations, soil impacts, and/or disturbance indicator plants.

Hydrologic Alterations- In general, if a wetland's hydrology - the amount and flow of water, at the surface or under the ground, and the duration of soil saturation - is altered, the wetland plant and animal communities will likely follow suit and become altered from their natural composition. The primary disturbance to wetland hydrology throughout rural Wisconsin is artificial drainage. Past ditching or buried drain tiles that remove surface and groundwater for the land to be used for cultivation alter the wetland’s hydrology and can have significant long-term negative impacts on the entire wetland. In urban areas the addition of stormwater runoff from streets and parking lots, yards, and roofs may degrade a water body or wetland. Storm sewers often drain directly into lakes, rivers, or wetlands, unloading excess water, chemicals, fertilizers, and other hazardous substances into these ecosystems.

Soil Impacts- If a wetland soil is extensively disturbed, an opportunity exists for aggressive invasive species to establish themselves. Impacts to wetland soils that affect vegetation may include cultivation, subsidence or erosion of muck soils, soil compaction due to cattle grazing or driving heavy machinery over a wetland, and placing telephone poles, pipeline, sewer lines, or underground cables. Once the wetland sod has been broken, invasive species can get a foothold and may eventually outcompete the less aggressive native plants. Siltation, or the accumulation of sediments, causes serious damage to wetland quality, especially in agricultural landscapes. Agricultural activities can cause soil erosion from fields to dump directly into adjacent wetlands. Sediments carry nutrients from manure and fertilizers, which may lead to changes in a wetland's vegetation and wildlife habitat. Reed canary grass and other invasive species may encroach on a wetland that has trapped silt from adjoining farm fields.

Disturbance Indicator Plants- All the disturbances mentioned above tend to reduce, modify, or change the quality of a wetland and its functional values, not to mention its aesthetic appeal. The biological diversity, or richness of plant and animal species in an area, can be seriously reduced through disturbance. A good wetland restoration project attempts to restore the original hydrology, plants, and animals to the site. Disturbed wetlands lose plant diversity and are typically dominated by only a few species. Several plant species frequently occur in the majority of Wisconsin’s disturbed wetlands. Becoming familiar with these species will help you determine the extent of disturbance. Purple loosestrife, reed canary grass, giant reed grass, and even cattails are extremely aggressive invasive plants that can grow under a number of conditions, ranging from wetlands with considerable seasonal inundation to relatively dry upland sites. Their presence indicates that some disturbance in the distant or recent past allowed the plants to gain entry. In many open wetlands in the southern areas of the state -- shallow marshes, sedge meadows, wet meadows, and wet prairies -- where the water table has been lowered and where fire has been suppressed, native and non-native shrubs and trees begin to invade. Glossy and common buckthorns are typical aggressive non-native shrubs that establish themselves. Native shrubs and trees that invade disturbed wetlands include red osier dogwood, gray dogwood, willows, prickly ash, quaking aspen, and box elder.

Gathering Information and Mapping the Site
It is helpful to inventory and map the features and ecology of a potential wetland restoration site. Start your planning by sketching a rough map of your site; the map you create will be the framework of your restoration plan. As you sketch a map of your site, note approximate locations of special features such as lakes, streams, or rivers nearby; topography of property (flat or hilly, note any large hills; ditches; drain tile outlets; springs; potential sources of water; standing water; cropland; roads/culverts; noticeable change in the types of plants; mature trees or shrubs; waterfowl or muskrat using the waterways; and any other clues of wildlife use. Take photographs to document pre-restoration condition.