Originally Posted by azn_redneck

Why? I'm licensed to practice civil engineering. Why would I ask a contractor to construct a basin with a top of wall (TOW) at elevation 0.99 ft when he would have a much easier time building the TOW at elevation 1.00? Engineering is not an exact science, nor does it need to be. Appropriate safety factors are always used to minimize risk without designing something that becomes economically unfeasible.