10611 EVERGREEN WAY KLEIN HONDA 2022-10-27

f • • SECTION III: SITE DEVELOPMENT PLAN W/ON-SITE STORMWATER MANAGEMENT The site area is 3.19 Acres. The proposal includes an extension to the current building with additional parking. The total disturbed area will be 0.5 acres with a total hard surface replacement quantity of 0.5 acres (21,760 SF). No new impervious areas are proposed. Minimum requirements 1-5 apply to the project as the proposal involves replacement of impervious surface. Refer to the Flowchart for Determining Requirements for Redevelopment attached in the next page. For onsite stormwater management(MR#5) full dispersion was considered first however it was deemed infeasible due to the lack of native vegetation. Downspout full infiltration was deemed infeasible due to the soils poor infiltration qualities. Bioretention was deemed infeasible due to the soils poor infiltration. Downspout dispersion system was deemed infeasible due to a lack of vegetative flow path. Perforated stub out connection was considered and deemed feasible. Onsite stormwater management for the roof area will be provided by perforated stub out connections. The overflow from the perforated stub out connection will be connected to the existing drainage system onsite that drains to the south within a closed pipe system. For other hard surfaces full dispersion was considered infeasible due to the lack of vegetation,permeable pavement and bioretention were deemed infeasible due to the soils poor infiltration. Sheet flow dispersion was deemed feasible and will be used. Pervious areas had no feasible BMPs due to the site being nearly 100% impervious. The proposed hard surface replacement quantities are: Roof Area = 0.17 acres ( 7,460 SF) Asphalt = 0.27 acres (11,837 SF) Concrete = 0.06 acres (2,463 SF) Total Hard Surface Replaced = 0.50 acres (21,760 SF) Insight Engineering Co. -Stormwater Site Plan 11/16/17 - 12 -