2009 - Illinois DNR - State of Illinois

ALTERNATIVE S9 -COMBINED STORAGE AT DUDE RANCH PONDEXPANSION WITH LAKE MARY ANNE PUMP STATION,GOOD AVENUE POND, LUTHERAN GENERALHOSPITAL POND, HIGH SCHOOL RESERVOIR, ANDBELLEAU LAKE LOWEREDTo achieve flood damage reduction benefits throughout the watershed, this alternativewould combine various storage alternatives including construction of a pump station atLake Mary Anne, modifications to the Dude Ranch Pond, modifications to the ChurchStreet culvert at Good Avenue Pond, modifications to the Lutheran General HospitalPond, construction of a new reservoir on the Maine Township High School campus andlowering of Belleau Lake. Each of the storage components of this alternative aredescribed below.The Dude Ranch Pond, located south of Golf Road and east of the Tri-State Tollway,would be enlarged and connected to Farmers Creek to increase upper Farmers Creekstorage by 30 acre-feet. Storage in the pond would be controlled by a new 48-inchdiameter outlet pipe through a provisional Class 1 dam structure constructed in theFarmers Creek channel just downstream of the pond. A 10 cfs pump station, with an 18-inch diameter discharge pipe, would be constructed on the south shore of Lake MaryAnne to pump water from Lake Mary Anne into the Dude Ranch Pond. The two 5cfspumps would substantially improve Lake Mary Anne’s outlet capacity and prevent 100year frequency event water levels in Lake Mary Anne from reaching all but onestructure. The normal pool elevation of Lake Mary Anne would remain unchanged at632.5. Overflows from the existing IDOT Golf Road interceptor sewer would also becontrolled by the Dude Ranch Pond site.Good Avenue Pond is located north of Church Street and west of Potter Road. Storagein the pond is controlled by the culvert under Church Street. To increase the floodstorage capacity of this pond, the existing Church Street box culvert would be modifiedby adding a three foot high weir constructed at the upstream end of the culvert wingwalls. The weir would have a 2-foot diameter opening to pass low flows in the channel.At the elevation of the new weir, the flood storage capacity of the pond would beincreased by 18 acre-feet to be used for more frequent events on Farmers Creek. Thisalternative would increase the retention time of storage used at the Good Avenue Pond.A levee constructed two foot high with 2:1 side slopes and with a 3 foot top width wouldprotect Good Avenue from higher flood stages in the pond. Storm sewers entering the53