Ann Arbor District LibraryGreen Roof and Infiltration BMPs

• Current MDEQ nonpoint source (NPS) program priority: innovative, low-impact storm water BMPs

• In August 2003, Library received $236,000 federal Section 319 NPS grant

• First green roof funded by MDEQ NPS program

Asphalt parking lotLandscaping/turfBest management practiceRetention basinGeneral flow pathOutlet to Malletts Creek

North

#

ProjectLocation

Site Plan

Green roof planted with sedum, spring 2004; sufficient

vegetative cover in ~1 year

roofdrain

Overflow (water not intercepted by green

roof) drains to ground

Overflow (water not intercepted by green

roof) drains to ground

Runoff from asphalt parking lot drains to…

…Bioswales, planted with goldenrod, blazing star,

dogbane, iris, etc., to provide infiltration

East

bioswale

Bioswale inlet lined with

gravel to slowwater

velocity

Notesedimentaccumulation

East

bioswale

Parkinglot inlet

Parkinglot

inlet

Eastbioswale

Wes

t

bios

wale

Westbioswale

Rock-lined channel to retention basin

Overflow outlet

Eastbioswale

Parking lot outlet to retention basin via rock-lined channel

Parking lot outlet to retention basin via rock-lined channel

Flow into upper retention basin

Retention basin—final BMP in storm water treatment train

Flow into lower retention basin

Retention basin—final BMP in storm water treatment train

Outlet toMalletts Creek

Retention basin—final BMP in storm water treatment train

Overflow

Curbmarkers

Curbmarkers

Curbmarkers

Sampling todeterminepollutant removal

Samplingdevice inlet