Fixed span bridges in a subdivision shall be constructed at a height of not less than eight feet above the mean high-water level and shall be constructed from plans and specifications prepared by a registered engineer and approved by the city. bridge design and construction shall conform to the state department of transportation "Standard Specifications for Road and bridge Construction." No road or bridge between fingers shall be constructed which will preclude access to the channel of the Banana River, as established by the U.S. Army Corps of Engineers.