July 1998 - Laserfiche WebLink

Home Browse Search

INDIANA DEPARTMENT OF NATURAL RESOURCES Division of Soil Conservation 60455 U.S. 31 South South Bend, IN 46614 (219) 291-2300 FAX (219) 291-3726 Michael Obleunis 934 Riverside Dr. South Bend, IN 46616 RE: Bank Erosion Dear Michael: LARRY D. MACKLIN, DIRECTOR May 19, 1998 This is a follow up to the May 15th site visit behind your home, along the south shore of the St. Joseph River in the SE 1/4 of the NE 1/4 of Section 2 Portage Township, in South Bend. The purpose of the visit was to get ideas on the control of natural bank slumping. The soil type for all three properties is a Tyner sandy loam escarpment. The enclosed diagram (figure 1) is an excellent example of the forces working to create the slope failures. The impermeable layer is probable somewhere close to the area of the flat shelf midway down the bank. Several ideas were discussed to control or manage the bank to prevent the erosion. The first recommendation is to minimize the amount of water peculating in to the bank. This can be accomplished by installing gutter down drain extensions to take all roof water down the slope, past the critical area. A splash -block or similar dissipator will be needed at the end to prevent erosion at the end of the tube. This should be done on all three properties. Also, reduce the amount of weight close to edge of bank. Another item discussed was terracing the bank. This is a good method of control but will be very labour intensive. The goal here should be to transform the long, steep, unstable slope into several short, flatter, more stable areas to better control runoff water and promote vegetation. The bottom terrace should be started as close to the toe of the slope as possible and anchored as much as possible. once the terrace wall is constructed, install a "breathable" filter fabric along the back off the wall. Install drain tubing behind the wall, along the bottom, and outlet on each end to remove excess water from the soil behind the wall. Backfill using soil from above. Use splash blocks at the end of the tubes on both ends. All yard waste material should be completely removed before starting so only clean soil is used. Vegetation should be planted and established as absolutely as soon as possible after each tear is completed. See form 42 for some recommended plants. The yard waste material can be composted to use as a soil amendment when planting the terraces or add good quality topsoil. Lightly sprinkle plants until established. "EQUAL OPPORTUNITY EMPLOYER"