The Big Green Sponge

THE “B

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IMPERVIOUS AREA IN CITY OF LANCASTER

Building41%

Parking Lot

32%

Railroad2%

Roadway25%

IT’S BEEN FUN, BUT NOW…

Figuring out scale

Institutionalizing

-ordinance

-sustainable funding

LEADIN

G BY

EXAMPLE

EXAMPLE DEMONSTRATION PROJECT POROUS PAVEMENT PLAY COURT: 6TH WARD PARK

6TH WARD PARK UNIT COST COMPARISON

PARKING LOTS

PLUM STREET PARKING LOT

PLUM STREET

TOTAL

Parking Lot Drainage Area

GI Area Capture Volume

Capital Costs with Contingency

Plum Street

23,402 4,680 511,000 $89,862

Dauphin 20,582 4,516 411,000 $61,822

Penn 22,758 4,219 455,000 $60,749

Mifflin 13,242 1,324 265,000 $27,013

TOTAL 1,642,000 $239,446

COST PER GALLON = $0.14/gallon

GREEN STREETS & ALLEYS

ALLEY 148: BEFORE

ALLEY 148: AFTER

HOW MUCH WE NEED TO MANAGE?

Area / Impervious SourceGreen Infrastructure Project /

Program Type

Assumed Percent of Impervious

Area Managed

Impervious Area

Managed (acres)

Total SW

Runoff (MG/yr)

Assumed WQv or

BMP Capture Volume

(in.)

Average Annual Runoff

Reduction

Runoff Reduction

(MG/yr)

Roads / Alleys Green Streets 30% 158.7 513 1.0 86% 132.4Parks Park Improvements / Greening 85% 17.0 19 1.0 86% 14.2Sidewalks Disconnection, Porous Pavement 35% 43.3 120 1.0 86% 36.1Parking Lots Porous Pavement, Bioretention 20% 129.5 628 2.0 97% 121.3Flat Roofs Vegetated Roofs 15% 32.7 212 1.0 86% 27.3Sloping Roofs Disconnection/Rain Gardens 25% 163.5 635 1.0 86% 136.5Street Trees Enhanced Tree Planting N/A 45.1 44 0.3 49% 21.5Public Schools Green Schools 75% 38.4 50 1.0 86% 32.0

Various (Ordinance) First-Flush Ordinance 50% 637.0 1236 1.0 86% 531.6

1,265 3,752 1,05355%

Total

PUT ANOTHER WAY…

Area/Impervious Source

Assumed Percent of Impervious Area Managed

Roads/Alleys 30% 468 Blocks

Parks 85% 26 Parks

Sidewalks 35% 89 Miles

Parking Lots 20% 287 Parking Lots

Flat roofs 15% 246 Roofs

Sloping Roofs 25% 2,195 Buildings

Street Trees N/A 56,700 Trees

Public Schools 75% 15 Schools

Various (ordinances)

50% 2,536 non-residence parcels

75%

11%

14%

Parcels

ResidentialMulti-FamilyNon-Residential

20%

4%

76%

Impervious Area

ResidentialMulti-FamilyNon-Residential

PARCEL VS. IMPERVIOUS AREA

OUR THANKS…

National Fish and Wildlife Foundation

Keith Campbell Foundation for the Environment

PA Department of Environmental Protection

PA Department of Conservation and Natural Resources

Lancaster County Planning Commission

Chesapeake Bay Commission

PENNVEST

And many individual donors…