The site is located on what is referred to in this PER as stream-major. Streambank erosion is occurring along both sides of the channel; however, the west side erosion adjacent to the residence at 5113 appears to be of greater significance due to the proximity of the adjacent structure and loss of actual property in terms of square footage. Streambank erosion at site 6 is within 15 feet of the rear corner of the residence. A foundation drain is exposed within the eroded area of stream bank.
The stream at this location has a rock bottom with a bottom width of approximately 15 feet. The bank on the west side is approximately 5.5 feet tall and is nearly vertical. The east side bank has a side slope of approximately 1.5H:1V. The site location is downstream of an existing 4’ x 8’ concrete box culvert under Millbrook Drive. Visible signs of erosion, scour, and undercutting of existing trees indicate the presence of high velocity flow typically seen in urban and suburban areas. The total length of eroding streambank from the box culvert to a reasonable distance beyond the rear corner of the residence is approximately 125 feet.