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Stormwater Management Facilities Report Outline

  1. Executive Summary
  2. Introduction
    • Evaluation of Existing Conditions
      1. Discussion of existing site conditions with Existing Site Resources Map, prepared per Site Design Guidance
      2. Determination of whether site is new development or redevelopment
      3. Determination of minor watershed and whether release rate or zero differential detention requirements apply (for projects with detention)
      4. Determination of any special existing conditions that warrant mitigation
    • Evaluation of Proposed Conditions
      1. Development use
      2. Define total disturbed area in acres
      3. Calculate differential runoff for 15-year 20-min (St. Louis County) or 20-year 20-min (St. Louis City) storm
      4. Description of stormwater management facilities proposed, with BMP Drainage Area Map (see BMP Drainage Area Map instructions)
  3. Water Quality/Channel Protection/Flood Protection MEP Calculation Tool (as applicable)
    • Hydrology
      1. Sizing of stormwater quality BMPs
        • Include volume reduction calculations
      2. Sizing of channel protection basin
        • Volume, rate, and orifice size calculations
      3. Flood protection detention basin report
    • Hydraulic Calculations
      1. Pipe sizing/hydraulic grade line calculations
      2. Culvert calculations
      3. Open channel calculations
      4. Any special structures (e.g. water quality flow splitter device)
      5. Flow velocities/erosion/revetment calculations
    • Appendix
      1. Existing Site Resources Map
      2. BMP Drainage Area Map
      3. Infiltration Tests/Borings/Geotech report
      4. BMP Reserve Area Plat (Maintenance Agreement Checklist)
      5. Proprietary BMP Cut-Sheets and O&M Manuals
      6. Structural Calculations
      7. BMP Typical Section
  4. Operation and Maintenance Plan (Separately Bound) (Operation and Maintenance Plan Guidance)
    • Post-construction Stormwater Management Site Plan and Drawings
    • General Stormwater Management Facilities Description
    • Site Contacts and Change of Ownership
    • Facility Maintenance Plan
    • BMP Type Specific Inspection Checklists & Description
    • Annual Reporting Requirement
    • BMP Waste Disposal
    • Maintenance Agreement
    • O&M Plan Revision