Harrisburg potential wetland compensation site : Level II hydrogeologic characterization report

Contract No. IDOT SWWIP FY04 to Illinois Department of TransportationOpe

Level II hydrogeologic characterization report : Sugar Camp Creek potential wetland compensation site: Franklin County, Illinois (Federal Aid Project 312, sequence number 9282)

Contract No. IDOT SW PESA WIP B FY07 to Illinois Department of TransportationOpe

Tree Establishment in Response to Hydrology at IDOT Wetland Mitigation Sites

The Illinois Department of Transportation (IDOT) has compensated for unavoidable impacts to wetlands in transportation project corridors by restoring and creating wetlands throughout Illinois. As part of the IDOT Wetlands Program, monitoring of performance measures is conducted by the Illinois Natural History Survey (INHS) and the Illinois State Geological Survey (ISGS). The goals of this research were to determine the effect of flood events on the establishment of planted and naturally recruiting trees in IDOT mitigation wetlands and to make specific recommendations for tree planting and the establishment of mitigation performance standards. We compiled and analyzed existing data from INHS and ISGS monitoring reports and conducted additional field surveys to determine long‐term planted tree survival and assess natural tree recruitment. Based on our compilation of data from INHS wetland monitoring reports, we determined that the number of planted trees alive at mitigation wetlands by the end of mitigation monitoring was, on average, 57% the number of trees planted originally. We revisited ten older mitigation wetlands in 2014 and recounted surviving planted trees, and found that survival rate continued to decline beyond site monitoring periods. Tree mortality was clearly related to site exposure to flood disturbance during individual years, through the end of site monitoring, and beyond site monitoring periods. Depth and duration of inundation were more important than flood frequency in determining tree survival. Natural colonization greatly exceeded planting in terms of both stem density and basal area. However, natural colonization was not clearly related to site flood exposure. In sites that are exposed to long‐duration or deep flooding, planted tree survival is likely to be low regardless of species planted or the degree of on‐site management of plantings. We recommend that realistically attainable mitigation performance standards be developed on a site‐specific basis, considering the likely hydrologic regime of the site. In some situations, faster‐growing species provide tangible environmental benefits. In addition, natural tree colonization can supplement planting, even in sites where planted hard‐ mast species are unlikely to persist.Illinois Department of Transportation, R27-143Ope

La Grange Wetland Mitigation Bank : level II hydrogeologic characterization report : La Grange, Brown County, Illinois

Submitted under Contract No. IDOT SW WIP 05 to Illinois Department of TransportationOpe

Water Quality and Levels in Trout Park Nature Preserve Before and After Reconstruction of the Jane Addams Memorial Tollway (Interstate 90), Kane County, Illinois

In 2014, the Illinois State Toll Highway Authority began reconstruction of the Jane Addams Memorial Tollway along Interstate 90, a segment of which is adjacent to Trout Park Nature Preserve in Elgin, Illinois. The preserve contains rare and sensitive fen habitat, several threatened or endangered species, and a remnant stand of northern white cedar. This fen habitat, the associated northern white cedar, and a perennial stream within the preserve rely on persistent groundwater discharge to the land surface. Before reconstruction, several impacts to the hydrology and water quality in the preserve were identified, including decreased groundwater levels due to underground drainage infrastructure and elevated levels of pollutants related to roadway runoff from Interstate 90 and Illinois Route 25, as well as leaky storm sewers within and adjacent to the preserve. To mitigate for these impacts, several changes were made to the drainage network and a concrete barrier wall was installed during reconstruction. Under contract with the Illinois State Toll Highway Authority, the Illinois State Geological Survey monitored surface and groundwater levels and water quality at Trout Park Nature Preserve before, during, and after reconstruction to evaluate the response of groundwater levels and water quality due to the reconfiguration of the storm drainage infrastructure. Results of monitoring show that the reconfiguration of the drainage network immediately resulted in increased groundwater levels along the north margin of the preserve. Although this water level recovery generally persisted after decommissioning of the former sewer lines, over the longer term a localized decrease in groundwater levels was observed at one monitoring location and likely reflects a reduction in surface-water runoff from Interstate 90 to the preserve due to the installation of the barrier wall. Before and after reconstruction, groundwater and surface water at the preserve had elevated levels of dissolved solids, mainly due to high concentrations of sodium and chloride resulting from decades of deicing activities along Interstate 90 and Illinois Route 25. After reconstruction, increased levels of dissolved solids, owing mainly to increased sodium and chloride in groundwater, were observed in two of three ISGS monitoring wells. These increases were likely due in part to rewetting and dissolution of residual legacy road salt along the Tollway apron as local groundwater levels increased. Reduced dissolved solids in the third well likely reflects reduced runoff from Interstate 90 following installation of the barrier wall, but is also attributed to a decrease in water level and no rewetting and dissolution of residual legacy road salt at this location. Decreased levels of dissolved solids were observed at all surface-water monitoring locations after reconstruction and likely reflect the combined effects of a period of increased precipitation after reconstruction and reduced influence from the reconfigured drainage network. The occurrence of metals commonly associated with roadways and observed in water samples from Trout Park Nature Preserve generally decreased after reconstruction, although detections of chromium, manganese, and nickel increased slightly after reconstruction.Illinois State Toll Highway Authority under contracts #ITHA RR-07-9918 and #ITHA 2015-01230 MINEROpe

Annual report for active IDOT wetland mitigation and hydrologic monitoring sites, September 1, 2014 through August 31, 2015

Ope

Annual Report for Active IDOT Wetland Mitigation and Hydrologic Monitoring Sites: September 1, 2018 through August 31, 2019

Illinois Department of Transporation Grant D6099Ope

Annual report for active IDOT wetland compensation and hydrologic monitoring sites, September 1, 2006 to September 1, 2007

Contract Number IDOT 2007-04065 ANTIC to Illinois Department of TransportationOpe

Annual Report for Active IDOT Wetland Mitigation and Hydrologic Monitoring Sites: September 1, 2016 through August 31, 2017

Ope

Annual report for active IDOT wetland compensation and hydrologic monitoring sites, September 1, 2004 to September 1, 2005

Ope