1028 BROADWAY 2016-01-01 MF Import

i I2.2 Post-Development Conditions I The site improvements will be demolished, cieared, and re-graded for the construction of a 34,432-square foot asphalt concrete parking lot. I In the proposed condition, access will be off Broadway Avenue from two driveways located in the north and south sections of the parkinq !ot. See Appendix A, Exhibit 2B. Onsite utilities wiil consist of slorm drainage piping and water for irrigalion. IStormwater facilit(es are proposed lo collecf and convey developed stormwater runoff. 'fhese facilities are described in Section 5.0 0(this report. I3.0 OFFSITE ANALYSIS I3.1 Downstream Analysis Site discharge will enfer the city II-inch combined sanitary and storm system in Broadway Avenue � at two points, one at a new manhole located at the approximate in[ersection of North Broadway and Broadway Avenue, and one approximately 232 feet north. Flow continues north in a closed 8-inch concmte sewer pipe. Flow eventually enters a sanitary sewer treatment plant. No adverse impact to the downstream system is anticipated because proposed stormwater runoff I will enter a ciosed combined storm and sanitary system, and lhe discharge points and peak fiows are approximately the same as in the pre-developed condition. I3.2 Upstream Analysis The relatively tlat nature of the topography precludes significant offsite contributory runoff to the � site. Runoff to the east is contained within the street storm system in Broadway Avenue. Runoff (rom the properties to the norlh and south foliow the natural flowpaths east toward Broadway Avenue. Runoff from propetties to the northwest colleds in an alleyway and flows toward 10"' Street. The only appreciable tributary runoff would be from the residential properties directly I west of the site, approximately 0.7 acre. These properties slope loward the site at approximalely 1 to 2 percent. Due the relatively flat slopes, it is anticipated tliat most runoff will be absorbed in the vegetation along the eastern portions of thesc lots. Tributary runoff to the site is anticipated Ito be minimal. See Appendix A, Exhibit 3. 4.0 ANALYSIS AND DESIGN OF REQUIRED EROSION AND ISEDIMENT CONTROL BMPS 4.1 System Description l • Construction entrance will be provided to reduce the amount oF sediment transported onto parcel roads by vehicles or equipment. , ( • Filter Fabric Fence will be provided along the downstream perimeter project dearing limils � to capture sediments from impacting downstream propetties or roadways. I • Catch basi� inlet protection wiil be placed on all offsite catch basin inlets affected by construction activities. ARer insta0ation of onsite catch basins, inlet protection will be provided as work progresses. I StonmvaterSitePlan QQOO Evcrett Community Colle9e . Topper Parking Lot . � 208221.10 �