Dunn Avenue Extension
The extension of Dunn Avenue west over I-95 connecting with Tomoka Farms Road provides Volusia County with a much needed alternative east-west route to relieve traffic on both heavily congested U.S. 192 to the south and LPGA Boulevard to the north. RS&H offered assitance in the following areas: field survey; geotechnical investigation; roadway, drainage, and structures design; and permitting services for the construction of over one mile of roadway on new alignment. The design accommodates the future widening of the avenue extension to four lanes within the 115-foot right-of-way.
The initial two-lane cross section includes two 12-foot lanes, a 5-foot paved outside shoulder with curb and gutter, an 8-foot sidewalk on the north side of the roadway, and a 4-foot paved shoulder adjacent to a future 20-foot raised median. The bid documents for the two-lane section incorporate all drainage structures to avoid any future reconstruction of the initial two-lane roadway. The team designed stormwater management facilities and provided permitting services for the proposed four-lane roadway, including three ponds, one of which is a joint-use pond with the Florida Department of Transportation. The team also developed mitigation for impacts to the Tomoka River Riparian Habitat Protection Zone, gopher tortoises, floodplains, and wetlands.
RS&H led the permitting effort, which included a U.S. Army Corps of Engineers permit for measures taken to minimize impacts to wetlands by avoiding a conservation easement near the Carolina Club building. Additionally, 2.25 credits were purchased from the Farmton North Bank to compensate for direct and secondary impacts. As mitigation for the Riparian Habitat Protection Zone impacts, three parcels of uplands and one wetland were preserved. The avenue extension project was included in the LPGA DRI, dated 1992. Wetland enhancement of 125 acres (mitigation:impact – ratio 3.5:1) were provided as compensation/mitigation for 35 acres of proposed wetland impacts. RS&H also obtained an Individual Environmental Resource Permit from the St. Johns River Water Management District and Advanced Approval from the U.S. Coast Guard.