From the From the BeginningBeginning

Design Standards and Other Post-Construction Program

Elements

Post-Construction BMPsPost-Construction BMPsLong term BMPs that help protect runoff throughout the life of the

completed project

Impervious AreaImpervious Area• More runoff, More Pollutants

Post Construction GoalsPost Construction GoalsWater Quality

Goals– Reduce

impervious area– Limit pollutant

exposure– Diminish

pollutant transport

Program Goals– Process to

ensure that “Water Quality Goals” are met

ProgramProgram• Ordinance requiring developers to

incorporate post construction BMPs• Strategy of BMPs • Enforcement of ordinance• Long-term operation and

maintenance of BMPs

OrdinanceOrdinance• Model Ordinance

– www.stormwatercenter.net– Model Urban Runoff Program

• Reference to separate document

BMP StrategyBMP Strategy• Site and watershed conditions

– constraints– topography– areas to utilize

• Pollutants of concern– 303(d) list– pollutants expected to be present

• Options• Sizing

BMPsBMPs

Site Design

Source Control

Treatment

Site DesignSite Design• Minimize building footprint• Cluster development (leaving more

useful open space)• Minimize directly connected

impervious areas (DCIA) – direct roof downspouts to landscape areas

• Protect slopes and channels• Aquatic buffers

Source ControlSource Control• Outdoor material storage areas• Trash enclosures• Equipment wash areas

TreatmentTreatment• Vegetated swales• Detention basins• Constructed wetlands

RequirementsRequirements• Attachment 4 -

Design Standards• Conserve Natural

Areas• Limit Directly

Connected Impervious Area

• Parking Lots

• Restaurants• Retail Gasoline

Outlets• Vehicle

Equipment Wash Areas

• Storage Volume • Treatment Flow

EnforcementEnforcement• Site Plan Review

– Checklist • Site Inspection

– As part of final approval

MaintenanceMaintenance• Legal agreements• Conditional use permits• Homeowner’s association• Conditions, covenants, and

restrictions• Databases• Inspections checklists