dhahn@hahn-eng.com

+845.279.2220

  • Stream and channel design
  • Culvert and drainage pipe design
  • Detention and retention systems
  • Stormwater retrofits
  • Phosphorous reduction
  • Green infrastructure
  • NYSDEC Stormwater Design (SWPPP)
  • MS4 Consulting
  • Watershed Planning
  • Flood Analysis
  • Grant Applications