The roadway designer should visit the site to observe existing conditions and limitations. The designer must avoid designs that may cause increased flooding or increased damage to adjacent, downstream, or upstream properties. TxDOT can be held liable for damages even if a design only increases the frequency of flooding to properties that are already regularly inundated. Overlays in areas where the water overtops the roadway may require milling prior to resurfacing in order to maintain the same elevation and not increase flooding. Problems caused by culverts and bridges can usually be avoided by alternative designs that will not significantly increase the cost. Ultimately, TxDOT must not be perceived as causing flooding to adjacent, downstream, or upstream property owners.