What stormwater management requirements apply to large-scale industrial tracts?

Large-scale industrial developments are subject to strict stormwater management regulations to prevent flooding, pollution, erosion, and non-compliance with local environmental laws. Proper design and infrastructure must handle peak rainfall events, protect downstream ecosystems, and meet planning and pollution control board standards.

Below are the key stormwater management requirements typically applied to industrial tracts:

1. On-Site Stormwater Collection and Conveyance System

• Requirement: Install internal drainage lines, catch basins, and culverts to collect runoff.
  
• Design Basis:
  
  • Based on 1-in-25 to 1-in-50-year storm events
    
  • Must ensure no waterlogging or surface flow off-site
    
• Infrastructure: Includes stormwater inlets, RCC drain lines, and underground pipes with proper slopes.

2. Detention or Retention Basins

• Purpose: To temporarily store or slowly release stormwater runoff.
  
• Application:
  
  • Required for large sites (usually >10 acres)
    
  • Volume is determined by site imperviousness and rainfall intensity.
    
• Types:
  
  • Detention ponds: Delay runoff release into municipal drains
    
  • Retention ponds: Store water permanently for reuse or infiltration

3. Rainwater Harvesting and Ground Recharge

• Requirement: Comply with state or municipal mandates for rainwater harvesting systems.
  
• Design Elements:
  
  • Recharge pits or trenches
    
  • Percolation wells near the roof or paved areas
    
• Objective: Enhance groundwater recharge and reduce load on storm drains.

4. Oil and Grease Traps for Paved Yards

• Required in: Vehicle parking areas, loading docks, and material handling zones.
  
• Function: Remove hydrocarbon pollutants from surface runoff before discharge.
  
• Design Must Meet: Pollution Control Board (PCB) guidelines for effluent quality.

5. Outfall and Discharge Approval

• Approval Needed From: Local municipal engineering department or pollution control board.
  
• Conditions Include:
  
  • Controlled outfall discharge to public drains or natural water bodies
    
  • No increase in downstream flow beyond baseline
    
  • Discharge points must be protected against erosion and contamination.