12 2026 02 12 Crestmont CC Stormwater Management Report

TABLE OF CONTENTS EXECUTIVE SUMMARY.............................................................................................................................. 1 1.0 INTRODUCTION .................................................................................................................................... 1 2.0 PROJECT DESCRIPTION ....................................................................................................................... 2 2.1 EXISTING SITE DESCRIPTION .................................................................................................................... 2 2.2 SUBSURFACE CONDITIONS ...................................................................................................................... 2 2.3 FLOOD HAZARD AREA ............................................................................................................................ 4 2.4 PROPOSED DEVELOPMENT...................................................................................................................... 4 3.0 STORMWATER MANAGEMENT .......................................................................................................... 4 3.1 STORMWATER QUANTITY DESIGN ............................................................................................................ 5 3.1.1 Design Criteria ............................................................................................................................. 5 3.1.2 Design Methodology ................................................................................................................... 5 3.1.3 Points of Analysis ........................................................................................................................ 7 3.1.4 Existing Watersheds ................................................................................................................... 8 3.1.5 Allowable Peak Discharges ......................................................................................................... 8 3.1.6 Proposed Watersheds ............................................................................................................... 11 3.1.7 Proposed Detention Routing ..................................................................................................... 12

............................................... 11 3.1.7 Proposed Detention Routing ..................................................................................................... 12 3.1.8 Quantity Control BMP Design Summary .................................................................................. 13 3.1.9 Stormwater Quantity Summary ................................................................................................ 15 3.2 STORMWATER QUALITY DESIGN ............................................................................................................ 16 3.2.1 Design Criteria ........................................................................................................................... 16 3.2.2 Design Methodology ................................................................................................................. 17 3.2.3 Design Summary ....................................................................................................................... 17 3.2.4 Trash and Waste ....................................................................................................................... 18 3.3 GROUNDWATER RECHARGE .................................................................................................................. 18 3.3.1 Design Criteria ........................................................................................................................... 18 3.3.2 Design Methodology ................................................................................................................. 18 3.3.3 BMP Design .............................................................................................................................. 18 3.3.4 Design Summary ....................................................................................................................... 19 3.4 NON-STRUCTURAL STORMWATER MANAGEMENT STRATEGIES ................................................................. 19 3.5 STORMWATER CONVEYANCE DESIGN ..................................................................................................... 19 3.5.1 Design Criteria ........................................................................................................................... 19

.................................... 19 3.5.1 Design Criteria ........................................................................................................................... 19 3.5.2 Design Methodology ................................................................................................................. 20 4.0 SOIL EROSION AND SEDIMENT CONTROL ..................................................................................... 21 5.0 STORMWATER MAINTENANCE PLAN ............................................................................................. 21 6.0 CONCLUSION ...................................................................................................................................... 21 7.0 REFERENCES ....................................................................................................................................... 21 i