From the From the BeginningBeginning

Design Standards and Other Post-Construction Program

Elements

Post-Construction BMPsPost-Construction BMPs

Long term BMPs that help protect runoff throughout the life of the

completed project

Impervious AreaImpervious Area

• More runoff, More Pollutants

Post Construction GoalsPost Construction Goals

Water 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