In order to prove that the restored mitigation is functioning properly the regulatory agencies require that the site be monitored. The current monitoring period for tree planted projects is for up to 10-years or until specific ecological success criteria are achieved. Wetland monitoring includes field indicators of hydric soil. These indicators prove that the anaerobic reducing conditions within the soil are cycling nutrients such as carbon and nitrogen. Herbaceous ground cover and trees must meet a minimum density and species composition. Wetness indicators such as drift lines and high water marks must be present in order support the hydrology that induces anaerobic soil conditions. Regulators are increasingly requiring the use of data-logging wells to prove that the soil is inundated or saturated within 12″ of the surface for the required time period.
Streams must meet a minimum habitat score and be stable. The tree-planted area along each side of the restored stream is called the riparian zone. As with wetlands, the vegetation communities must meet minimum performance standards in order to provide habitat, shading, water filtration and other functions.
As discussed in the mitigation section, the key to success is the actual site. Site conditions also determine how much maintenance will be required during the 10-year monitoring period. Maintenance is usually required at a minimum to control undesirable vegetation. This is done by mowing, prescribed fire and/or chemical control. Other consultants often seek wetland sites along major rivers such as the Green, Wabash & Ohio because they flood frequently. These locations however are susceptible to high-velocity flows and scour, deep drift deposits and ice damage on newly planted trees. Many invasive species from other continents have been imported to America and spread easily on floodwaters. Immediately after the restoration site is excavated is when it will be most susceptible to infestation by undesirables. The ecological conditions of a site completely dictate how much maintenance is ultimately required. We select sites and design plans based on minimum ongoing costs with the greatest likelihood of success.
If you have a potential mitigation site we will evaluate it, provide a percent likelihood of full success, and estimated maintenance costs. If you need a site we can provide info for available sites within the various service area watersheds of the Illinois Basin. We are not real estate agents, but maintain a working knowledge of the various landowners with high quality sites.