storm-ez – partnershipsnorthcarolina.apwa.net/content/chapters... · balancing water quality...
TRANSCRIPT
STORM-EZ – Partnerships
STORM-EZ – Challenges Addressing the Problem
Continued water quality degradation despite increased regulation
Balancing water quality protection with economic development
Paperwork for multiple SCMs complicates permitting
STORM-EZ – Solutions Changing Behaviors
Change in hydrology metrics
Application, Calculations, O&M in on spreadsheet
Variable sizing & credit based on SCM type
STORM-EZ - Paperwork
STORM-EZ - Paperwork
Conventional Development LID Development
Hybrid Developments
STORM-EZ – Flexibility
STORM-EZ – Discrete CN Method
STORM-EZ – Discrete CN Method
Runoff from Impervious Surfaces
Runoff from Open Space +
= Total Runoff
STORM-EZ – Discrete CN Method
Initial abstraction of pervious areas cannot influence runoff from impervious areas
LARGER SCMs (EQUIVALENT OR BETTER
TREATMENT, BUT INCREASED DEVELOPMENT COSTS)
SMALLER SCMs (REDUCED WATER QUALITY
PROTECTION – NOT EQUIVALENT)
STORM-EZ – Discrete SCS Method
STORM-EZ – P90 Storm & State Rules
STORM-EZ – P90 Storm & State Rules
STORM-EZ – SCM Crediting New SCM Sizing Methods
Credit based on SCM type and soil type
Undersized SCM’s OK
Treatment Trains OK
Fate of Rainfall
Fate of Rainfall
Fate of Rainfall
Storage Volume
Bypass Volume
Post Filtration Discharge & Treated Outflow
Infiltration
Evaporation & ET
STORM-EZ – SCM Crediting
STORM-EZ – SCM Crediting
Stormwater Control Measure
STORM-EZ – SCM Credits
Wetland
Wet Detention
Bioretention
Bioretention w/IWS
85% TSS Removal
Why Pursue Volume Matching?
QUESTIONS?