Laserfiche WebLink
7601 Ganser Way <br /> BARRIENTOS Madison,Wisconsin 53719 <br /> 608.833.8560 <br /> Engineers & Architects FAX 608.833.8921 <br /> June 21, 1996 <br /> Mr. Rich Vogt }� ������ (1)) <br /> Department of Natural Resources <br /> Southern District Office <br /> JUN 7 199/ <br /> ' <br /> 3911 Fish Hatchery Road <br /> Madison, WI 53711 <br /> HESSLINK LAW OFFICES, S.C. <br /> Re: Slotten Airport <br /> Town of Verona <br /> Dane County <br /> Dear Rich: <br /> I am completing the above referenced project, for Dave McDermid because he is currently <br /> working out of the office on a construction project. Based on the information you gave Dave <br /> over the phone and the Flood Insurance Study (FIS) and HEC-2 run sent through the mail, we <br /> have decided it best to go back to the original concept of placing a 60 inch culvert pipe in the <br /> streambed under the proposed runway rather than realigning the creek around the runway. This <br /> eliminates the need for a Type II Environmental Assessment, Corps Permit, and wetland <br /> mitigation. <br /> The HEC-2 file you sent was imported into HEC-RAS to analysis the existing and proposed <br /> conditions. New cross sections were added at Stations 49.7, 49.8, & 49.9. These sections are <br /> located downstream of the proposed culvert, at the downstream edge of the proposed culvert and <br /> at the upstream edge of the proposed culvert, respectively. Section 50 is located upstream of the <br /> proposed culvert and is where the water surface elevations are compared. Even though the <br /> runway is downstream of this section, the runway was shown on this cross section to account for <br /> the narrower passage between the hill in this section and the corner of the runway. There appears <br /> to be some inconsistencies between HEC <br /> Since the flow values used in the FIS are higher than what Dave previously used the water <br /> surface is higher, the floodplain is wider, and the proposed runway has much less impact on <br /> water elevations. The proposed runway is about 3 to 4 feet lower than the water surface <br /> elevation at the design flow and the downstream culvert has a great deal of influence on the water <br /> surface elevation. So as it turns out, the proposed culvert and runway don't raise the water <br /> surface elevation. <br /> The 60 inch pipe will be approximately half buried into the streambed so that it will fit under the <br /> runway with adequate cover. The pipe will carry all normal flow, even though it will cant' very <br /> little of the design flow. <br />