Hydrologic and hydraulic analyses were done for parts of Abel Ditch, Edson Creek, Maurer Ditch, and Sherod Creek1 in northeastern Vermilion Township, Erie County, Ohio. For each stream, instantaneous peak discharges for floods having recurrence intervals of 2, 5, 10, 25, 50, and 100 years were estimated using regional regression equations. Factors used in the regression equations were drainage area, a basin development factor, and average annual precipitation. Drainage areas at the selected stream locations ranged from 0.41 to 4.61 square miles.
A step-backwater model was used to determine water-surface elevation profiles for the 10- year-recurrence-interval (10-year) flood along a selected reach of each stream. The water-surface profile information was then used to prepare a map of flood-plain boundaries. Hydraulic analyses indicated that the 10-year flood was generally confined within the stream channels. At three locations, however, some of the flood discharge escaped the main channel and flowed overland. In two cases, the overland flow returned to the channel from which it escaped. In the third case, flow drained into an adjacent basin. A separate analysis, in which concurrent flood peaks on the streams studied were assumed, indicated that water would spill over the Sherod Creek and the Maurer Ditch divides and that some of this water would eventually enter the Edson Creek Basin downstream from the study area.
1Locally the upper reach of Sherod Creek, south of the Conrail Railroad, is known as Japson Ditch. However, for simplicity it will be referred to as Sherod Creek along its entirety.
