RAIN GARDENSJulia Jones

Purpose

“Rain gardens can effectively trap and retain 99 percent of common pollutants in urban storm runoff, potentially improving water quality and promoting the conversion of some pollutants into less harmful compounds”

The Problem• Typical urban setting 75%

impervious coverage• 50% storm water runoff• Pollution

• Metals• Oils• Fertilizers• Other “particulate matter”

The Solution• Rain garden hydrologic

cycle• Two types

• Under-drained• Infiltration not desire• Pipes transport clean water• Porous planting media• 2 hours to drain

• Self-contained• Infiltration • Porous planting media• 4 hours to drain

RAIN GARDENS IN SITE PLANNING

Site Inventory• Issues

• Erosion• Compaction of soil• Excess runoff volume• Eye sores

• Positive Attributes• Good views• Existing vegetation and plant

species• Travel patterns

Site Inventory• Features

• Wind and sun direction• Noise pollution• Infrastructure• Site drainage patterns• Slopes• Soil types

Site Analysis

Placement and Size • Moisture and

water issues• Traffic patterns• Wildlife• The cost of

excavation

Site Analysis

Type• Moisture• Soil types• Environmental

and aesthetic functions

• Maintenance initiatives

Case Study• 2 year study conducted

• Michael Dietz and John Clausen of the University of Connecticut

• Storm water runoff from rooftops

• Significantly reduced concentrations of nitrates, ammonias, phosphorus, and other pollutants

Lansing Michigan• Sewage overflow plan• Incorporated in the streetscape• Michigan Ave

CONCLUSION• Rain gardens are effective• Practical and aesthetically pleasing• Incorporated in site planning process