green infrastructure in new york city · 1 green infrastructure in new york city stormwater source...
TRANSCRIPT
1
Green Infrastructure in New York CityStormwater Source Control Performance
John McLaughlin, NYCDEPJulie Stein, NYCDEPSandeep Mehrotra, PE, Hazen and SawyerWilliam Leo, PE, HDR-HydroQualMatthew Jones, PE, PhD, Hazen and Sawyer
September 14, 2012
2
Acknowledgements
NYC DEP
Horsley-Witten
GeoSyntec
Brooklyn College
3
NYC Green Infrastructure Plan
Build cost‐effective grey infrastructure
Optimize the existing wastewater system
Institutionalize adaptive management, model impacts, measure CSOs, and monitor water quality
Sustain stakeholder engagement55
Control runoff from 10% of impervious surfaces through green infrastructure and other source controls
54
52
51
53
4
Stormwater Pilot StudyObjectives
Develop stormwater pilot designs
Construct and maintain pilots within NYC
Evaluate pilot performance
5
Stormwater Pilot Highlights
B Public Housing PilotsC Storage Building Blue RoofM Roadway Median BioretentionP Permeable Pavement
6H&
S F
ile: 9
0034
-Pre
sent
atio
n
2011 Precipitation Patterns
0
1
2
3
4
5
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Storm Rainfall D
epth (in)
0
1
2
3
4
5
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
5‐min Peak Ra
infall Intesity
(in/hr)
Percentile
7
Bioretention
8
Bioretention:Example 0.4” Storm
0.0
0.2
0.4
0.6
0.8
1.00.00.20.40.60.81.01.21.4
8/21/11 12:00 8/21/11 16:48 8/21/11 21:36 8/22/11 2:24
Rai
n In
tens
ity
(in/h
r)
Cum
ulat
ive
Rai
n (in
)
0
1
2
3
4
0
10
20
30
40
50
8/21/11 12:00 8/21/11 16:48 8/21/11 21:36 8/22/11 2:24
Surf
ace
Stor
age
(in)
Flow
(gpm
)
Inflow Rate Outflow Rate Surface Storage
9
Bioretention:Example 4.8” Storm
10H&
S F
ile: 9
0034
-Pre
sent
atio
n
Bioretention 1-4: Vol. Retained
Bio 1 - 7:1 Bio 2 - 6:1
Bio 3 - 9:1 Bio 4 - 17:1
11
Bioretention:Preliminary Observations
Bioretention areas retaining much of the water they receive– Most outflow associated with storms >1”
Curb cuts are not 100% effective at runoff captureLeaf and litter pickup part of routine maintenanceCommunity frequently comments on BMPs and are interested in project
12
Subsurface Detention & Infiltration
North Parking Lot
South Parking Lot
13
Stormwater Chambers:Example 4.8” Storm
14H&
S F
ile: 9
0034
-Pre
sent
atio
n
Stormwater Chambers:Inflow and Outflow
15H&
S F
ile: 9
0034
-Pre
sent
atio
n
Stormwater Chambers:Volume Retained
16
Stormwater Chambers:Preliminary Observations
Subsurface systems effective at capturing runoff (no bypass)
Chamber system not generating consistent outflow
Outflow rates have been below design target (0.25 cfs)
No substantial maintenance needs
17
Roadway Median Bioretention
18
Median Bioretention:Example 1.1” Storm
19
Median Bioretention: Vol. Retained
20
N&S Conduit Bioretention:Preliminary Observations
Most storms have been fully retainedApparent infiltration losses along conveyance swales
21
Permeable Pavement
22Porous Asphalt Standard Asphalt FilterPave
Permeable Pavement
23H&
S F
ile: 9
0034
-Pre
sent
atio
n
Permeable Pavement
0%20%40%60%80%
100%
0.0625 0.25 1 4Volu
me
Ret
aine
d
Rainfall Depth (in)
0%20%40%60%80%
100%
0.0625 0.25 1 4
Volu
me
Ret
aine
d
Rainfall Depth (in)
0%20%40%60%80%
100%
0.0625 0.25 1 4
Volu
me
Ret
aine
d
Rainfall Depth (in)
Standard Asphalt
Porous Asphalt Filterpave
24
Permeable Pavement:Preliminary Observations
No measured flow from filterpave and porous asphalt underdrainsOn-site tests suggest porous asphalt may be generating surface runoff
25
Multiple Blue Roof Systems
26
Blue Roofs:Example 1.9” Storm
0.0
0.2
0.4
0.6
0.8
1.00.0
0.4
0.8
1.2
1.6
2.0
10/29/11 0:00 10/29/11 12:00 10/30/11 0:00 10/30/11 12:00 10/31/11 0:00
Rai
n In
tens
ity
(in/h
r)
Cum
ulat
ive
Rai
n (in
)
0
2
4
6
8
10
12
14
10/29/11 0:00 10/29/11 12:00 10/30/11 0:00 10/30/11 12:00 10/31/11 0:00
Flow
(gpm
)
Uncontrolled
27H&
S F
ile: 9
0034
-Pre
sent
atio
n
0
4
8
12
0:00 12:00 0:00 12:00 0:00
Flow
(gpm
)
0
4
8
12
0:00 12:00 0:00 12:00 0:00
Flow
(gpm
)
0
4
8
12
0:00 12:00 0:00 12:00 0:00
Flow
(gpm
)
0
4
8
12
0:00 12:00 0:00 12:00 0:00
Flow
(gpm
)
Control Trays
Blue Roofs:Example 1.9” Storm
Uncontrolled Modified Inlet
Check Dams Trays
28H&
S F
ile: 9
0034
-Pre
sent
atio
n
Blue Roof: Peak Flow Reduction
Uncontrolled
Check Dams Trays
Modified Inlet
29H&
S F
ile: 9
0034
-Pre
sent
atio
n
Uncontrolled
Check Dams Trays
Modified Inlet
Blue Roof: Volume Retained
30
Blue Roof:Preliminary Observations
All roof types (including uncontrolled) providing some level or retention and detention
Trays and check dams appear to be providing more detention than uncontrolled and modified inlet
Modified inlet performance possibly inhibited by lack of available rooftop storage due to 2% roof slope
31
Monitoring Study Summary
Preliminary observations indicate pilots are providing benefits range of benefits
Findings will be validated and expanded upon through further data collection and analysis
Further data analysis and metrics will providing greater insight into CSO planning
Information on maintenance needs and qualitative performance informing future implementation efforts
32
Questions?
www.nyc.gov/html/dep/html/stormwater/index.shtml
Matthew Jones, EI, PhDHazen and Sawyer, [email protected]