CCA utilizes various methodologies in the computations of storm runoff and subsequent storm system sizing. The Rational Method is utilized for small, simple drainage areas and DOT procedures and technical publications assist in the hydraulic design for the piping and waterway system.
For more complex drainage systems, CCA utilizes PC versions of TR-20 and TR-55. Storm flows are routed through detention basins to determine downstream flows and velocities. Above and below ground storage systems are provided if necessary, to assure compliance with regulatory standards and the principals of good engineering practice.
Erosion and sedimentation control plans and specifications are designed based upon the results of the drainage analysis. If warranted, Storm-water Pollution Prevention Plans (SWPPP) are prepared for individual sites.