PB 22 10 Altera 769 LLC Filed Application with Exhibits Final Site Plan Phase 2

TABLE OF CONTENTS I. Introduction ............................................................................................... 3 II. Existing Site Conditions ............................................................................. 3 III. Proposed Site Conditions ........................................................................... 5 IV. Design Methodology .................................................................................. 6 V. Aboveground Stormwater Management Basin Design ................................ 7 VI. Runoff Rates .............................................................................................. 8 VII. Water Quality ............................................................................................ 8 VIII. Groundwater Recharge .............................................................................. 9 IX. Conclusion ................................................................................................. 9 APPENDIX • NRCS Web Soil Survey • Runoff Curve Number (CN) Calculations • Time of Concentration (Tc) Calculations • Existing & Proposed Hydrographs 2yr, 10yr, & 100yr Design Storms (Hydrographs created using Hydrology Studio 2020 Computer Software) • Existing & Proposed Hydrographs 1yr Water Quality Design Storm (Hydrographs created using Hydrology Studio 2020 Computer Software) • Rip Rap Calculations • Inlet Area Calculations and Stormwater Collection System Calculations (Pipe Sizing) • Basin Drain Time Calculation • Stormwater Basin Area Investigation Report prepared by Dynamic Earth, LLC, dated January 14, 2022 • Drainage Area Maps Altera 769, LLC 2 Revised August 2022 DECPC #2530-99-006