12011 19TH AVE SE PARKING LOT 2021-12-23

STORM DRAINAGE OPERATIONS&MAINTENANCE MANUAL SEPTEMBER 25,2019 EMORYS VALET PARKING 2 INTRODUCTION This Operations and Maintenance Manual provides detailed information and guidelines on the proper maintenance of the on-site storm drainage system. The Manual has been based on the requirements of the 2016 Department of Ecology Stormwater Manual (DOE Manual). Inspection and maintenance requirements may change in the future, and this manual does not exempt this facility from any future changes in inspection and maintenance requirements. The record documents should be consulted during inspection, maintenance and repair activities; a copy of the record documents is kept at the City of Everett Permit Services and in the office for the Emorys restaurant. DRAINAGE NARRATIVE Drainage from the parking, future building and portion of the public roadway is directed using a combination of sheet flow and gutter flow to catch basins, and storm pipe to the combined Detention/Stormwater Wetland Pond. The Stormwater Wetland provides treatment through removal of sediments and other pollutants while the detention pond and flow control structure provides storage volume and limits the release of runoff from the site. A flow diffuser will be installed at the outlet of the storm system to disperse runoff into the wetland on the adjacent property. FACILITY MAINTENANCE RESPONSIBILITY The owner of the Emorys Restaurant will be the responsible party for maintenance of the private storm drainage systems. This includes all storm systems that lie within the property boundary, including the catch basins and storm pipe, treatment systems and the detention pond. FACILITY DESCRIPTION The following are drainage items in this system and a description of their function: Storm drainage pipe: Conveys runoff underground from one point to another. On this site, storm drainage piping is limited to 8" PVC pipe. Catch Basins/Yard Drains: A structure used to collect surface water and direct it to a storm drainage pipe. They can also be used as junctions between runs of storm drainage pipe. Catch basins are larger concrete structures; rectangular or round. Yard drains are typically used for collection of runoff from landscape or courtyard areas. No yard drains are used on this site. Stormwater Wetland Treatment Facility: The Stormwater Wetland provides treatment through removal of sediments and other pollutants. Detention Pond:The detention pond provides flow control to reduce runoff rates from the site. P:1Work\Projects12018\18-141 Emorys\CE\DOCSSStorm Maintenance Manual 17-319.docDWH/SRTt