Stormwater Management Report Feb 2026 resubmissionrcd 2 26 2026

evaluated with the following drainage sub-watershed areas as depicted on the Existing Drainage Area Map included in the Appendix of this report. Point of Analysis #1 Study Area 1A: This area consists of 0.637 acres which include roof, motor vehicle surfaces, impervious and grass areas. Under existing conditions, stormwater runoff generated by this area flows to the five (5) on-site inlets, as depicted on the Existing Inlet Area Map. Existing Conditions Input Summary Table Drainage Area Name Drainage Area Time of Curve Number (acres) Concentration (CN) (minutes) EDA 1 - Impervious 0.396 Ac 1.6 98 EDA 1 - Pervious 0.241 Ac 4.5 61 Existing Conditions Flow Summary Table Drainage Current Adjusted Rainfall Projected Adjusted Rainfall Area Conditions Conditions Name Q2 (CFS) Q10 (CFS) Q100 (CFS) Q2 (CFS) Q10 (CFS) Q100 (CFS) POI #1 1.55 2.65 5.01 1.90 3.26 6.55 4. Proposed Drainage Conditions The proposed development has been designed to generally maintain similar drainage patterns as the existing condition. As shown on the Proposed Drainage Area Map in the Appendix of this report, the majority of the stormwater runoff for the proposed development will be captured by the proposed inlets and yard drains and conveyed to the same offsite region as in the existing condition. Moreover, the proposed development will incorporate a small bio-retention basin to the west of the proposed building along the site frontage, and an underground pipe storage detention basin to the north of the proposed building along the northern property line for stormwater management. The basins are designed to detain stormwater runoff generated by the development to meet the stormwater management requirements. The proposed site conditions have been evaluated using the following drainage sub-watershed areas as depicted on the Proposed Drainage Area Map included in the Appendix of this report. Point of Analysis #1 Uncontrolled: This area consists of 0.355 acres and

following drainage sub-watershed areas as depicted on the Proposed Drainage Area Map included in the Appendix of this report. Point of Analysis #1 Uncontrolled: This area consists of 0.355 acres and includes motor vehicle surfaces, impervious and grass areas throughout the site. Under proposed conditions runoff generated by this area sheet flows into the proposed storm conveyance system and discharges in the same location under existing conditions. Mavis Tire Supply, LLC July 2025 DEC# 1956-24-04187 3 Last revised February 2026