N
0 100
400
transportation infrastructure
03
17
600
+
public transit
conceptual diagram
Transit-Oriented Approach
+
surface parking lots
+
stormwater Bmps
=
effective Green stormwater Infrastructure
design concept Given that multiple transit lines and transportation corridors cross the project area, the opportunity emerges to combine best management practices for stormwater management with public and private transportation. BMPs can be incorporated into transportation infrastructure, can enhance public transit facilities, and can take advantage of large parking lot surfaces.
Furthermore, the fact that high volumes of commuter traffic flow along Market, Chestnut, and Walnut Streets every day makes BMPS along these routes highly visible.
N
0 100
to subu
400
18
600
rbs
MARKET
ST.
to cent e
CHESTNUT ST
41st ST
r cit y
SANSOM ST
WALNUT ST
to cent e to subu
r cit y
rbs
LOCUST ST
SPRUCE ST
50 th ST FARRAGUT ST
to clark park & trolley lines
03
site Design
Green Transit Corridor
Key
Rail rain garden
tree trench
BMP Bus Stop
bioswale
pervious parking lot
N
0 100
400
19
600
MARKET ST
CHESTNUT ST
41st ST
SANSOM ST
WALNUT ST
LOCUST ST
SPRUCE ST
50 th ST FARRAGUT ST
03
site Design
Market Street Wavegardens
Key
Rail rain garden
tree trench
BMP Bus Stop
bioswale
pervious parking lot
20
At 46th St. emerges and runs along an elevated track to the west along Market St. Between 50th & Farragut St., the tracks add up to 84,000 sq ft (almost 2 acres) of impervious surface. Run-off polluted by contact with heavy metals of the cars and rails is piped directly through downspouts into the sewer system. Because these pipes are exposed just above the pylons, they could be disconnected and redirected through green stormwater infrastructure systems.
03
site Design
Market Street Wavegardens
The Market St. median also presents opportunities to locate infrastructure and enhance the under utilized space beneath the elevated rail. Precedent for public art exists on painted pillars near the station entrances. Working in partnership with the Mural Arts Program or other arts organizations, stormwater infrastructure can showcase community artwork along the elevated rail corridor.
21
Precipitation
Elevated track run-off
Evapotranspiration
soak
store
divert
street & Sidewalk run-off infiltration
overflow diversion
03
site Design
Market Street Wavegardens
elevated track run-off
cistern
cascading rain garden
Each section of track contributes around 130 cubic feet of run-off during a 1� storm that is sent directly into the combined sewer system from downspouts in the track pylons.
By disconnecting the track downspout at the base of each pylon, stormwater run-off can be diverted into adjacent cisterns with a capacity of 950 gallons - a volume that holds 90 percent of run-off from each section of track during a 1� storm.
Rain gardens feature hardy local plant palette that filter stormwater, but also build upon a tradition that incorporates art into the public realm. The planters provide a surface for local artwork, while drawing attention to the urban hydrologic cycle and stormwater management in Philadelphia.
N
0 100
400
22
600
MARKET ST
CHESTNUT ST
41st ST
SANSOM ST
WALNUT ST
LOCUST ST
SPRUCE ST
50 th ST FARRAGUT ST
03
site Design
Public Transit Green Way
Key
Rail rain garden
tree trench
BMP Bus Stop
bioswale
pervious parking lot
23
Four bus lines cross the project area. The 21 travels east and west on Walnut and Chestnut Streets, while the 31 and 64 travel north-south on Farragut Street and intersect with the 46th Street El station. Because most bus stops in the project area do not have shelters and coincide with low points and sewer inlets on many block corners new shelters could be designed to divert or intercept run-off from streets and sidewalks before it flows into sewers. Green stormwater infrastructure along these highly trafficked routes would also be visible to many residents and can treat run-off from relatively wide streets.
03
site Design
Public Transit Green Way
The creation of bus stop shelters can also provide the location for interpretive signage about stormwater issues in Philadelphia and public art. Precedent for creative bus stops exists on stylized shelters in Center City. Working in partnership with the Next Fab Studio or other arts organizations, stormwater infrastructure can showcase water sculptures or other artwork along bus route corridors.
24
sidewalk run-off D
divert
soak B C
Street run-off
E A
C B
store
D
roof run-off
03
site Design
Public Transit Green Way
greened streets
bmp bus stops
A combination of pervious soft and hardscape can treat both a city block and adjacent streets.
Feature green or stylized roofs that direct stormwater to cisterns for storage and distinctive signage announcing the bus stop. Also the location for public art and interpretive signage about stormwater management.
A b C D E
bmp bus stops tree trenches & swales pervious parking lane subsurface vault bump-out & raised intersection
N
0 100
400
25
600
MARKET ST
CHESTNUT ST
41st ST
SANSOM ST
WALNUT ST
LOCUST ST
SPRUCE ST
50 th ST FARRAGUT ST
03
site Design
Greened Grocery Lot
Key
Rail rain garden
tree trench
BMP Bus Stop
bioswale
pervious parking lot
Over 15 surface parking lots exist on blocks along the main sewer line and the Mill Creek burried flood plain. These lots illustrate a pattern of demolition as buildings were removed over time due to deterioration and subsistence problems. Because they lie at low points in the project area, they not only present the opportunity to remove large areas of impervious surface, but to also site green stormwater infrastructure projects that can easily treat an entire block or more.
03
site Design
Greened Grocery Lot
The parking lot at 44th and Walnut is one such example. Once the location of cave-ins, many residents now frequent the lot and grocery store. At 37,000 sq ft, the lot presents a significant opportunity to reduce run-off and improve the aesthetic qualities of the area. The development of green stormwater infrastructure systems in parking lots allows for projects where a large area can be addressed with the cooperation and partnership of one property owner. In addition, they create the potential to network projects and divert water from multiple blocks.
26
27
roof run-off
evapotranspiration
parking lot run-off
soak infiltration sidewalk run-off
store
street run-off
subsurface vault
A
corner
03
B
divert
wide edge
site Design
Stormwater Parking Lots
C
corner edge
D
strips
greened blocks
parking lot design
The construction necessary to treat an entire city block can fit within a large parking lot.
Improvements occupy 20% of the lot and manage stormwater from the entire block.
A b C D E
corner wide edge Corner edge strips pixels
A subsurface vault adds storage capacity and captures water from the street and surrounding blocks. Tree trenches add continuity to the stormwater corridor and allow for infiltration.
E
pixels
Decision Criteria development pressure
block location infiltration