United States Department of the Interior FISH AND WILDLIFE SERVICE Chicago Illinois Field Office 1250 South Grove, Suite 103 Barrington, Illinois 60010 847-381-2253 FAX 847-38l-2285 FWS/AES-CIFO May 14, 2001 Col. Mark Roncoli District Engineer U. S. Army Corps of Engineers Chicago District 111 N. Canal Street Chicago, IL 60606 Attention: Michael Murphy CELRC-CO-R Dear Col. Roncoli: This responds to your Public Notice for application 200001139 submitted by Mr. Anthony DeSantis for construction of a commercial development along Indian Creek at Half Day Road and Milwaukee Avenue in Lincolnshire, Illinois. The proposal includes adverse impacts to approximately 12.85 acres of wetland. We have reviewed the information included in the Public Notice, though note that as posted on your web site it only included one exhibit. We conducted a site inspection on May 10, 2001 and at that time were afforded a cursory review of more detailed plans in your project file. We do not have any detailed information on the site plan or the mitigation proposal in our files. The wetlands on site consist primarily of degraded wooded communities. There are native plants scattered in low numbers in the understory, and an area of emergent/sedge meadow remnant included in the area to be impacted. Most of the area is apparently in the floodplain of Indian Creek. Presuming that the applicant can demonstrate to your satisfaction that they cannot further avoid or minimize impacts to these wetlands, we have the following concerns regarding proposed mitigation. The applicant proposes to mitigate for the wetland impacts associated with this development by planting wetland species in the compensatory floodplain storage area to be created adjacent to Indian Creek. The area encompasses a portion of the existing wetland and would be lowered in elevation by up to four feet from existing conditions. Excavating to a depth of 4 feet from existing condition would place attempts at establishing a wetland plant community in the subsoil or C horizon of the soil. While we do not have any site specific soil information, this area is mapped as Sawmill silty clay loam in the published Soil Survey for Lake County. This soil is an alluvial soil frequently found in floodplains. The subsoil is generally silty clay loam with occasional seams of gravel, sand, silt, and loam. It may not be suitable for growing wetland vegetation. If the topsoil or A horizon is stockpiled and respread over the site to provide a better growth medium, a typical practice, it would require very careful handling to avoid severe compaction problems given the clay content of such a soil. * We do not have any information on the anticipated hydrology of this proposed mitigation area, and understand that your office has received only general information- We recommend that you require the applicant to submit detailed information of the depth and duration of inundation for the 1, 2, 5, and 10 year flood events to determine if it is suitable for the establishment of wetland. The depth to the water table will also be an important consideration- * Since much of the wetland proposed for impacts is a mature forested floodplain community, your Public Notice suggests that you are seeking in-kind mitigation at a ratio that offers some compensation for the time delay until maturity. We offer that we have recommended a 3:1 mitigation ratio on another Corps of Engineers project in Lake County, based on habitat unit trade-offs. We believe that a similar mitigation ratio is appropriate here. * Without some of the additional information requested above and a detailed review of the planting proposal, we cannot determine the amount of mitigation credit the wetland plantings within the compensatory storage area may warrant. However, it is also clear that additional mitigation credits will be needed- Thus, we request the opportunity to review any revised mitigation plans, including any off site mitigation alternatives- * We recognize that this is primarily a public flood control Project, but the 4-5 foot deepening of the channel seems excessive without documentation of the reasons. In most instances in the Chicago region streams are naturally downcutting due to increased velocities from urbanized watersheds. Overall, we arc concerned that the mitigation proposal offered by the applicant does not provide enough assurance of replacement of wetland functions or acreage. Based on the information provided in the submittal and a review of our records, we concur that the project is not likely to adversely affect any federally listed threatened or endangered species or adversely modify designated critical habitat. This precludes the need for consultation in accordance with section 7 of the Endangered Species Act of 1973, as amended. Should project modifications or new information indicate that endangered or threatened species may be affected, consultation with the Service should be initiated. This letter provides comment under the authority of, and in accordance with, the provisions of the Fish and Wildlife Coordination Act (43 Stat. 4O1, as amended; O U.S.C. 661 et seq.) and the Endangered Species Act of 1973, as amended (87 Stat. 884. as amended; 16 U.S.C- 1531 et seq.). If you have any questions regarding our comments, please contact Mr. Jeff Mengler at 847-381-2253, ext. 226. Sincerely John D. Rogner Field Supervisor cc: IDNR, Schanzle Lake Co SMC, Corona