MMSD’s Regional Green Infrastructure Plan and The Role of Permeable Pavement

May 1, 2014

Karen Sands, AICP

Manager of Sustainability

Milwaukee Metropolitan Sewerage District

Milwaukee Metropolitan Sewerage District

We Serve: • 1.1 Million Customers

• 28 Municipalities

• 411 Square Miles

We Protect the Public & Lake Michigan:

• Convey/Store/Reclaim Wastewater

• Manage Flooding

We Do This With Infrastructure:

• Grey

• Green

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Green Infrastructure

• Complements Traditional Grey Infrastructure

• Uses Vegetation and Soil/Foundation to Manage Water Where it Falls

• Provides a Host of Benefits that Pipes Can’t

Porous Pavement’s Benefits

• Reduces Polluted Stormwater Runoff

• Recharges Groundwater

• Reduces Urban Heat Island Effect

• Melts Snow/Ice

Porous Pavement Is…

• Green Infrastructure

• Not Green, per se, but Acts Green: – Infiltrates – Stores – ≠ Evapotranspires

• Types: – Concrete – Asphalt – Concrete or Plastic Stones/Pavers,

Grids, and Geocells

Green Infrastructure In MMSD’s Discharge Permit

4.10 Wet Weather Management-Green Infrastructure

“…The practices/control measures put in place in 2013 must cumulatively have a design retention capacity of at least 1

million gallons, and each following calendar year during the permit term an additional 1 million gallons of green

infrastructure retention capacity must be put in place...”

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MMSD 2035 Vision’s Green Infrastructure Goals

• Capture the 1st 0.5” of rainfall

• Capture & reuse the 1st 0.25 gallon per SF

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Regional Green Infrastructure Plan

Porous Pavement Goes Where?

Primarily….

• Public/Private Streets

• Parking Lots

Recommendations by Green Infrastructure Strategy

740 MG =

How Big is That?

1,190 acres (900 football fields)

How Much is That?

155,400,000 gallons (2,800,000+ rain barrels)

How Much Will That Cost?

Cost Type Cost/Gallon Cost/Gallon Managed

Incremental $ 6.60 $ 1.65

Full $10.00 $ 2.50

• Total Incremental Cost of Porous: $364M

• $0.10/SF Managed Annually

Regional GI Plan Recommends Combinations

Regional GI Plan Recommendations

• Develop Regional Maintenance Standards

• Address Equipment/Training Needs

• Support Demonstration Projects

• Develop Parking Lot Retrofit Screening Program

Karen Sands, AICP Milwaukee Metropolitan Sewerage District

ksands@mmsd.com 414-225-2123

www.mmsd.com www.h2ocapture.com