the big green sponge
TRANSCRIPT
THE “B
IG G
REEN SPO
NGE”
J UN
E 5
, 2
01
2
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…