SDA is an industry leader in storm drainage design, including water quality, detention, conveyance, and basin analysis. We are comfortable working throughout the State of Washington.

Our staff has provided storm drainage expertise for highways, freeways, corporate campuses, retail complexes, plats, single- family residences, and municipal projects. We are proficient in WWHM, KCRTS, SBUH modeling, MGS Flood, conveyance analysis, Hec-Ras, and other modeling techniques. We have also prepared permit packages for NPDES, Sand and Gravel Surface Mining, and Department of Ecology Dam Safety. Because of our expertise, we are called upon to provide peer review of stormwater systems and inspection of as-built facilities for several jurisdictions.