The upcoming regulations will hopefully result in more design flexibility and better stormwater quality. However, for these regulations to work to their fullest extent, localities will need to make changes to development ordinances to fit with the new approach. Here are some examples:
- The most cost effective way for developers to reduce runoff volume is to never build pavement. However, the local ordinances often drive the need for pavement through required parking, road width, fire access, road and other factors. There is very good discussion of this in the book Suburban Nation: The Rise of Sprawl and the Decline of the American Dream. A few localities in Virginia have started the process of reducing requirements for pavement in their ordinances, but there is a long way to go.
- The new regulations use sheet flow across undeveloped and landscaped areas as a way to reduce runoff volume. It makes a lot of sense and I think it will become a mainstay in engineer’s toolkits. However, many subdivision ordinances currently require curb and gutter for subdivision roads. Curb and gutter not only eliminates sheet flow (proposed Option 2) as an option, but makes grass channels (Option 3) more difficult to implement. Given that roads are usually the single largest component of impervious area in subdivisions, eliminating curb and gutter should be an option.
Many localities have already incorporated clustered development in their regulations, which allows more flexibility to reduce impervious area. We need to build on this in advance of the implementation of the proposed regulations using the resources currently available to localities, including consulting engineers and non-profits. It is also an opportunity for DCR to become a clearinghouse of ideas and efforts by issuing model ordinance language and promoting the best ordinances being adopted.