Last year I completed the BASMAA Post-Construction Manual, which applicants for development project approvals will use to design site drainage and incorporate rain gardens (bioretention facilities) into their projects. The manual implements requirements in Provision E.12 of the California State Water Resources Control Board’s Phase II Small MS4 General Permit.
The manual will be used by Marin, Sonoma, Napa, and Solano Counties, and by the small cities within those counties, so it has a fairly wide reach. It can (and I think will) be adapted for use by smaller cities, towns, and counties throughout California.
During January I completed an Excel-based calculator that should facilitate the iterative design process needed to prepare an elegant and optimal LID drainage design. It felt great to create what I think will be a quite useful tool in only a day (project budget was 8 hours, prepared for the City of Napa).
Additional resources: The instructions are in a tab within the calculator, but it might be helpful to also have them as a separate Word file. Also, the manual includes Technical Criteria for Non-LID facilities, but for bewildering and complex reasons these had to be published separately.