STORMWATER REGULATIONS CONTINUE TO CHANGE
Stormwater regulations across the country continue to increase in both scope and intensity. Many of the reasons for increasing stormwater regulations are directly related to property development. Developing a piece of property often entails taking it from a natural state, where 50% of precipitation infiltrates and only 10% runs off to an improved state, where only 15% of precipitation infiltrates and 55% runs off. For many decades, this increase in runoff has caused many detrimental issues such as downstream flooding, erosion, receiving water impairment, and beach closures while the decrease in infiltration has left our drinking water aquifers on a serious decline.
California is no exception to the changing regulatory landscape, which is why I jumped at the chance to attend an all‐day event put on by Santa Clara Valley Urban Stormwater Pollution Prevention Program (SCVURPPP) in Campbell, California. The purpose of the workshop, which was held on Tuesday, June 16th, was to identify and discuss the upcoming changes to the NPDES Permit for the area, known as the Municipal Regional Permit (MRP), and recognize a number of projects that addressed stormwater runoff in unique and creative ways. The current MRP, which is expired, has been extended until reissued some time later this year. Updated permit language will include a number of significant changes that are likely to affect how property gets improved or developed.
As my day at the workshop went on, it became very clear that directing stormwater off a developed property will never again be an acceptable practice. When speaking about rainfall runoff these days, terms like low outfall, storm drain, and channel have been replaced with rainwater harvesting, infiltration, and low impact development. The former relate to managing rainfall runoff with off‐site facilities and the latter relate to managing it on‐site, right where it falls. Though low impact development (LID) design principles have been around for many years, the new MRP will likely require LID measures to be much “greener”. The reissued MRP is expected this upcoming December, so stay tuned…
Acrobat versions of all presentations delivered at this year’s workshop are available here SCVURPPP C.3 Workshop – June 16, 2015.
Jim Mayer
Technical Marketing Engineer
Torrent Resources