Operating under permits from the Oregon Department of Environmental Quality (DEQ), Environmental Services operates and maintains Portland’s sanitary sewer collection system and two wastewater treatment plants, and manages systems that convey stormwater runoff to streams, creeks, and rivers and to groundwater. These permits require Portland to manage stormwater runoff in a way that protects public infrastructure, human health and safety, and the environment.Portland’s Stormwater Management Manual (SWMM) contains stormwater management design requirements for all Portland development, redevelopment, and improvement projects on private and public property and in the public right-of-way.
Portland requires development and improvement projects to manage stormwater runoff on-site. The SWMM shows developers and property owners a variety of methods to reduce the impact of stormwater runoff on sewer systems, groundwater, rivers and streams. Examples of approved stormwater management facilities include landscaped swales, stormwater planters, vegetative filters, and landscape or underground infiltration.
In January 2014, the city released an updated version of the SWMM. Project designers have the option of using the 2008 Stormwater Management Manual or the 2014 manual until April. After April 2, 2014, all project designers must use the 2014 manual.
The 2014 SWMM is available for download at www.portlandoregon.gov/bes/SWMM.