Lessons from developing a stormwater management comprehensive design-review process

Excerpt

Postconstruction stormwater regulators generally require hydrologic designs generated by approved science-based tools. They then review those designs to ensure that all pertinent rules and codes are met. This design-review sequence is done in various ways, but unfortunately the pass/fail bar is often not clearly defined, making the roles of both designer and reviewer more difficult than necessary. We herein describe a system built to integrate and improve the process, taking into account feedback from both reviewers and regulators while incorporating a physically based model accurately describing site hydrology. We hope this experience and lessons learned will help others develop similar design-review approaches for postconstruction stormwater or other natural resource development.

Comprehensive design-review must aim toward a common ultimate goal. The US Environmental Protection Agency (USEPA) promulgated postconstruction stormwater rules, establishing local regulatory bodies as Municipal Separate Storm Sewer System (MS4) entities based on their management of infrastructure collecting urban stormwater runoff and discharging it to streams and rivers (USEPA 2018). Each MS4 must develop a comprehensive plan using ordinances, permits, education, and guidance to encourage progress so that discharges will ultimately meet expectations. The rules hold both for individual permits for larger communities (Phase 1 MS4s) and for state general…