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4.0 PRELIMINARY AGENCY REVIEW 4.1 The proposed riverbank erosion protection along the St. Joseph River in South Bend, Indiana, has been coordinated with the U.S. Fish and Wildlife Service, the U.S. Environmental Protection Agency, the State of Indiana, and various Native American Indian tribes, groups, and interested parties. Comments received are addressed below. . 4.2 The U.S. Fish and Wildlife Service (FWS): The FWS provided comments on the proposed riverbank erosion protection project (See February 24, 2000, letters, Attachment B, Pages B-1, B-4, and B-8). They noted that another erosion site on the west side of the Leeper Park Island should be added to the bank protection project and that they prefer repairing the WPA wall so that the riprap will not intrude on the overall outdoor experience of visitors to the park. 4.3 The proposed action includes repair of the WPA wall. The area of erosion on the west side of the island was previously inspected but not included in the project because the damage is due to surface erosion and, therefore, is outside the scope of work authorized under Section 14 of the Federal Flood Control Act of 1946. 4.4 The FWS believes that the North Shore Drive site cannot be addressed by any single protection alternative because of the variability of the on -the -ground situation. They suggest that soil stability and degree of erosion should be determined along the entire length of the slope, since erosive pressures are not uniform across the entire area. Then areas of varying erosion potential could be individually addressed. 4.5 The selected alternative for the North Shore site, riprap protection, has been redesigned to include a bio -engineered erosion control turf mat along the upper bank where the erosion potential is lower. This alternative can be adjusted to varying slopes and tree populations and . will blend well into the existing riverbank at each end of the reach. Evaluation of this alternative at various cross-sections along the North Shore site shows it is suitable for the full reach. Approximately 30 trees with 6 -inch and greater stem diameter would remain along the North Shore Drive riverbank above the riprap. Approximately 18 of these trees would be saved as a result of using the bio -engineered upper erosion control instead of additional riprap. 4.6 The FWS noted a delta in the river by the CSO protection site that appears to be pushing some flows toward the North Shore Drive riverbank. They suggest that removal of the delta and control of its source may relieve some of the erosive pressures against the north bank of the river. Concern also was expressed by the FWS about the long-term viability of the proposed bank protection at the North Shore site. They suggested modeling the river dynamics at and upstream of the project reach to help develop a successful long-term bank protection solution. 4.7 Excavation of the delta is not authorized under Section 14 of the Federal Flood Control Act of 1946. Regarding river dynamics, the proposed bank protection design was based on available data for flow velocity and stages. Based on the relatively slow flow velocities, additional modeling to define the erosion potential is not considered necessary. The selected