Low Impact Development (LID)

LID Approaches

PreserveExisting

Vegetation

Restoring Roadside

Landscape

Minimizing Impervious

Area

MaintainSheet Flow,

Dispersionpatterns

MaintainInfiltrationPatterns

Retrofit existing

StormwaterFeatures

PorousMaterials

PRESERVE EXISTING VEGETATION

RETROFIT OR RESTORE USING A SOIL AMENDMENT

BEFORE

AFTER

VEGETATED SIDE SLOPE RETROFITTED WITH A SOIL AMENDMENT

BEFORE

AFTER

SLOPE RETROFITTED WITH A SOIL AMENDMENT

FLAT BOTTOM CHANNEL WITH A SOIL AMENDMENT ADDED

BEFORE

AFTER

RESHAPED CHANNEL AND INSTALLING SOIL AMENDMENT

Treatment Solution SelectionFor project with identified water

Issues and treatment goals

Incorporate LID techniques suchas soil amendments, impervious

surface reduction, preservingor restoring adjacent roadway landscaping

Submit hydraulic Design Deviation for other BMP

not listed in WaterQuality Guidance/Tech Bulletin with supporting

documentation

Select appropriatetreatment based on:

• BMP removal capabilities• Constructability• Cost and maintenance• Site constraints (steep Slopes, high groundwater, Bedrock, etc)

Go to StormwaterManagement Tech

Bulletin and attachedWater Quality Guidance

Sufficient LIDs Incorporated?

Water Quality SelectionComplete

YN

BMP selected from Recommended listFrom Water Quality

Guidance/Tech Bulletin?

N

Y

LIDs and/or EngineeredTreatment option used

To meet treatmentgoals

Sufficient design?

Y

Re-Submit deviation for for other BMP

not listed in WaterQuality Guidance/Tech Bulletin with supporting

documentationN

Design Guidance

StormwaterManagement

Tech Bulletin

(GE-09-02B)

LID GuidanceUnder

Development

LID Guidance

LID Types

SelectionProcess

Siteconsiderations

Operation andMaintenance

Site Constraints

SizingCriteria