Blueprint Columbus is a first-of-its-kind plan that other cities and countries are seeking to emulate. Sanitary sewer overflows occur when rain water gets into the sewer and overwhelms it. The traditional solutions just treat the symptoms – too much stormwater overwhelming the existing capacity of the sanitary sewer – by building larger pipes. Blueprint attacks the root of the problem by addressing the rain water entering the sewer system. Instead of building more infrastructure, Blueprint invests in rehabilitating and correcting existing infrastructure.