2022 08 Drainage Report

IV. PROPOSED SITE CONDITIONS As noted above, the proposed development includes the development of four new single-family residential houses with assumed footprint sizes totaling approximately 9,600 SF (2,400 SF each) with accompanying driveways. Additional site improvements include constructing stormwater management facilities for each subdivided lot. The stormwater management system includes four (4) aboveground small-scale bioretention basins also known as rain gardens to detain stormwater runoff generated by the development in order to meet the stormwater management requirements set forth by the Township of West Orange and NJAC 7:8. The proposed site conditions have been evaluated using the following drainage sub-watershed areas as depicted on the Proposed Drainage Area Map included within the Appendix of this report. Study Area asant Avenue Undetained: This area consists of a small portion of the northern-most and easterly disturbed portions of the subject area which includes open grass cover for which stormwater runoff is undetained. Stormwater runoff from this area flows via overland flow to the east, ultimately tributary to Mount Pleasant Avenue located east of the site. Study Area Basin A: This area consists primarily of the stormwater runoff associated with the development of improvements associated with the proposed Lot 1 located at the south-west portion of the tract, which includes the proposed single-family residential house, driveway, a small portion of Ridge Road, and open grass/lawn cover. Stormwater runoff from this area will flow overland to the proposed bioretention basin located at the east side of the proposed lot. Stormwater runoff generated within this area is ultimately tributary to Mount Pleasant Avenue located at the east of the site. Study Area Basin B: This area consists primarily of the stormwater runoff associated with the development of improvements associated with the proposed Lot 2 located at the south-west portion of the tract, which includes the proposed single-family residential house, driveway, a small portion of Ridge Road, and open grass/lawn cover. Stormwater runoff from this area will flow overland to the proposed bioretention basin located at the east side of the proposed lot. Stormwater runoff generated within this area is ultimately tributary to Mount Pleasant Avenue located at the east of the site. Study

bioretention basin located at the east side of the proposed lot. Stormwater runoff generated within this area is ultimately tributary to Mount Pleasant Avenue located at the east of the site. Study Area Basin C: This area consists primarily of the stormwater runoff associated with the development of improvements associated with the proposed Lot 3 located at the north-west portion of the tract, which includes the proposed single-family residential house, driveway, a small portion of Ridge Road, and open grass/lawn cover. Stormwater runoff from this area will flow overland to the proposed bioretention basin located at the east side of the proposed lot. Stormwater runoff generated within this area is ultimately tributary to Mount Pleasant Avenue located at the east of the site. SHI Builders August 2022 DEC# 4266-99-001 -3-