Agenda - Planning Commission - 02/01/2007

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Integrating Stormwater Regulation and Urban Design By Lisa Nisenson Landmark Supreme Court decisions are the yardsticks by which we judge the constant battle over who can do what and where. But every once in a while, groundbreaking events in land use are not heralded by head. lines, but rather are contained in the tiny font of local newspaper notices, footnotes, or within regulatory bulletins such as the u.s. government's Federal Register. On December 9, 1999, one such final notice was issued by the u.s. Environmental Protection Agency (EPA) in the vernacular of water engineers under the heading "Stormwater." Terms such as "National Pollutant Discharge Elimination System" and "non-structural techniques" are largely unfamil- iar to land-use and zoning managers. The EPA ' regulation contained two curious clauses that are as much land use as they are water quality. First, the notice directed over 5,000 cities across the country to consider for the firsttime "post-construction" stormwater control. More importantly, the notice instructed that these new post-construction rules be implemented "by ordinance or other regulatory mechanism" a.e., zoning and land development regulations). Most cities have engaged in stormwater control for decades though drainage require. ments. But the new EPA rules challenge the old engineering approaches of draining a city's runoff into the most convenient local stream. The new approach scrutinizes the capture and handling of stormwater in nearly every site plan proposal to lessen the impacts of development. This issue of Zoning Practice will demys- tifythe new requirements, link them to common zoning and planning efforts already under way, and offer cautionary observations about the potential for unintended results when merging land-use and water regulations. NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM The National Pollutant Discharge Elimination System (NPDES) is the section of the Clean 44 Water Act that regulates discharge into water- ways. In the beginning, NPDES looked mainly at discharges with the highest pollutant loads, which typically came from factories and large pipes. In the early 1990s, the regulations were expanded to cover stormwater flows from large cities with populations over 100,000. The 1999 notice (referred to as Phase II) brought smaller urbanized areas under regula- tion for development projects of one acre or more. NPDES permits require renewal every five years, allowing time for program man- agers to adapt and customize their systems. EPA delegates NPDES authority to most states, which then develop a statewide gen- eral permit that spells out municipal compli- ance requirements. For planning and zoning, the most important elements are the post-con- struction rules and the stormwater manage- ment plan that specify best management prac- tices (BMPs). EPA materials issued to date include BMPs for traditional water bodies as well as guidance on using land-use practices such as infill and increasing open space pro- tection-integrated "by ordinance or other reg- ulatory mechanism." Why Post-Construction? Post-construction stormwater measures help control runoff after the completion of a project by assigning some measure of responsibility for stormwater control to developments over the life of the project. In the past, the engineer's job was to remove water from the site and into the ZONINGPRAaJCE 11.06 AMERICAN PlANNING ASSOCIATION I page 2