Environmental Services Design Report - Vand i Byer

Scope of work for retrofit projects: The project is anexample of how retrofit projects typically incorporateimprovements that go beyond the immediate goal ofstormwater management. The rain garden project included anadjacent plaza at the south entrance to the school; it wouldhave been visually incongruous to leave the old asphaltsurface. The parking lot swale includes three crossings;although three were not required, they significantly improveaccess for pedestrians.Geotechnical research: In retrospect, it would have savedtime and money to field-test geotechnical conditions moreextensively prior to construction. Given the variable conditionsand the fact that two drywells had to be abandoned due tohigh groundwater during construction, hiring a drilling rigduring the planning phase would have proved valuable.Downspout disconnected to a splashblock ("runnel")Grading (topography): The swale in the parking lot is anexample of how challenging it can be to integrate theelevations of new concrete curbs and flatwork with existingasphalt surfaces. Even with extensive prior survey work, anumber of adjustments were needed during and afterconstruction to ensure that runoff enters the facility asintended.Runoff entering the rain garden from adisconnected downspoutStructural integrity of curbs: Future designs shouldinclude stronger curbs adjacent to newly paved surfaces in order to allow finishing of the pavementwith a mechanical roller. Concerns about the structural integrity of the curbs on the north side of theparking lot swale made it too risky to use a finishing roller, which in some cases modified the intendedtravel path for the runoff.ACKNOWLEDGEMENTSPortland Public SchoolsNancy Bond, Resource Conservation Specialist, Facilities and Asset Management DivisionCynthia Gilliam and Van Truong, Principals of Mt. Tabor Middle SchoolBrian Anderson, Assistant Principal of Mt. Tabor Middle SchoolBureau of Environmental ServicesHenry Stevens, Project ManagerKevin Robert Perry, Project DesignBrandon Wilson, Project EngineeringPatty Nelson and Brad Huard, Construction ManagementREFERENCESKurtz, T. E.; Rauscher, T.; Hickey, M. (2004) Glencoe Rain Garden Flow Test Memorandum: August12, 2004. Sustainable Stormwater Management Program, Bureau of Environmental Services,City of Portland, Oregon.Kurtz, T. E. (2006) 2006 Stormwater Management Facility Monitoring Report. SustainableStormwater Management Program, Bureau of Environmental Services, City of Portland,Oregon.Stevens, H. S.; Hauth, E. (2007) Design Report: Rain Garden at Glencoe Elementary School;Sustainable Stormwater Management Program, Bureau of Environmental Services, City ofPortland, Oregon.10