3721 OAKES AVE EVERETT MEMORIAL STADIUM 2018-12-21

P engineering p c EVERETT MEMORIAL STADIUM BASEBALL FIELD REPLACEMENT STORM DRAINAGE REPORT AUGUST 15,2017 REVISED SEPTEMBER 15,2017 PROJECT OVERVIEW This Storm Drainage Report is for the replacement of the baseball field at Everett Memorial Stadium,home of the Everett Aquasox baseball team. The project site address is 3802 Broadway in Everett,Washington. Refer to Figure 1—Vicinity Map for the site location. The project is located within the City of Everett and has been designed in accordance with the City of Everett Stormwater Management Manual (SWMM)and the 2016 ordinance to Update Everett Municipal Code 14.28,which has adopted the 2014 Department of Ecology(DOE) Stormwater Management Manual for Western Washington(SMMWW).Additionally,Everett Public Works Director Interim Policy#2-11 applies,which outlines stormwater control requirements in a combined sewer area. Refer to the minimum requirements section of this report for the project classification and the minimum requirements that are applicable to the project area. The project will include the resurfacing of the existing natural grass baseball field and clay infield. In the proposed conditions,both the outfield and infield areas will be replaced with synthetic turf surfacing. The existing underdrain system in the outfield will be retained,while a new underdrain system will be installed for the infield.The footprint of the field will remain unchanged. Existing Conditions The Everett Memorial Stadium property is one parcel(#29052900300100)with an area of approximately 28.73 acres. The project area consists of a minor league baseball stadium with a natural turf field with clay mix infield and cinder warning track. There are grandstands and bleachers to accommodate roughly 3,700 fans.The disturbance area is bounded by 38th Street to the north,the football/track facilities to the west,an open lawn area to the south,and the Everett Aquasox office facility and parking lot to the east. The total project disturbance area is approximately 123,399 square feet(2.833 acres). The project is in a combined sewer basin,as designated by the City of Everett.A 36-inch combined sewer line runs diagonally across the baseball field footprint.The existing grass outfield is currently underdrained with perforated lateral drainage pipes spaced approximately 15-feet on center running northwest-southeast.An 8-inch collector drain line running southwest-northeast conveys flow to a Type-1 catch basin located in centerfield below the field surface.From here,an 8-inch outlet connects the combined sewer system continuing to the northeast via the 36-inch combined sewer line.The infield portion of the field is not currently underdrained. Based upon the City of Everett's Critical Areas maps,the project area is not within any sensitive areas,such as erosion hazards,landslide hazards,liquefaction,or wetland areas. There are areas designated as steep slopes to the east of the field.Additionally,the project is not located within a floodway, 100-year floodplain,or stream bank area according to the Federal Emergency Management Agency(FEMA)Flood Insurance Rate Map.