Presenters: S.W.I.M., NRDC, Sustainable South Bronx, NRDC.

1. Water
August 20 Forum
Häfele Showroom

2. S.W.I.M.
• Clean Water Act = Fishable and Swimmable
• Storm Water Infrastructure Matters
• Over 45 members, including Gowanus
Dredgers, Nos Quedamos, Cook + Fox,
NRDC, Sustainable South Bronx
• www.swimmablenyc.info

3. PROBLEM
• CSO = combined sewer
overflow
• More than 27 billion
gallons of untreated
stormwater and raw
sewage per year
• 460 CSOs in NYC

5. SOLUTION
• Green infrastructure, Low
Impact Development
(LID), Best Management
Practice (BMP), Source
Control
• Interagency BMP Task
Force
• Citizen Implementation

6. Natural Resources Defense Council
• Larry Levine, Project Attorney
• a S.W.I.M. member organization
• Local Law 5 – requires a “Sustainable
Stormwater Management Plan” for NYC
– 1/30/08: Intro 630-A approved unanimously
– 2/19/08: Bloomberg signs into law
– 10/1/08: First draft due, for public review &
comment
– 12/1/08: Final Plan DUE

7. Local Law 5
• Mayor’s Office of Long Term Planning and
Sustainability has lead responsibility; quarterly public
meetings to solicit input – next meeting anticipated in
Oct.
• Key Plan Elements:
– focus on “green infrastructure”
– code revisions for new development and redevelopment
– financial and other incentives for retrofitting
– design specs for public projects
– long-term and interim goals and milestones
– public notification of CSO events
• Complete progress report due every 2 years

8. Local Law 5
Example BMPs:
• Rain gardens
• Downspout disconnection
• Green roofs
• Enhanced street tree pits and planting strips
• Rain barrels
• Pervious pavement
• Rainwater harvesting
• Water conservation; greywater re-use
• Stormwater Utility Fee (separated from water rates)

9. Sustainable South Bronx
• Rob Craudereuff
• Green Roof Tax Abatement
• Passed NYS in June 2008

10. Rob Crauderueff
SUSTAINABLE SOUTH BRONX

14. USA USA
5% = 25%
World’s ?
Population

15. USA USA
5% = 25%
World’s World’s
Population Incarcerated

16. •Problems to be addressed:
•Unemployment: 25%
•Living in POVERTY: 40%
•Median Household Income: $20K

21. Bronx Ecological Stewardship Training

25. Source: Columbia University Urban Planning Studio, 2006 Instructors:
J. Rosenthal & K. Bakewell

27. Green Roof Tax Abatement
• $4.50/s.f. up to $100,000
• 3 year maintenance plan
• Agreement for City to inspect
• Applications:1/1/09? - 3/15/13

28. Green Roof Tax Abatement
• At least 50% of the roof, green roof defined
as:
– Roof Membrane
– Root Barrier
– Insulation
– Drainage
– Growth Medium (3 inches or irrigation or certified)
– Vegetation (80% covered)

29. EDAW
• Timothy Terway
• Urban Design Meets Urban Ecology
• Interdisciplinary Practice: Different Disciplines
engaged in Studying Systems

30. How do we make this…. function like this?

31. Green Stormwater Infrastructure:
What is it?
• Integrated, landscape-based
approach to sustainable
development
• Set of strategies to maintain
existing natural systems,
hydrology, ecology
• Flexible approach based on
a toolkit of simple techniques

32. Stormwater Complimentary
Goals Goals
• Water quality improvement • Wildlife habitat
– Filter pollutants and • Greening cities,
contaminants aesthetics
• Recreation and open
• Water conservation space
• Peak flow control • Environmental education
& stewardship
• Volume reduction
• Shading / heat island
reduction

33. The NEW Paradigms – Urban
Water Cycle

34. Landscape Transition
SFPUC 2007

35. What is your primary goal?
– Water quality
– Aquifer recharge
– Combined Sewer Overflow (CSO) reduction
– Green streets
– Flood reduction

36. Toolkit
• Green Roofs
• Cisterns
• Downspout Disconnection
• Rain Gardens
• Bio-Retention
• Detention Basins
• Constructed Wetlands
• Permeable Paving
• Stream Daylighting
• Urban Forest

37. Case Studies:
• Jordan Cove, CT
• 100 acre Urban Regeneration
Masterplan (New York Metro)

38. Stormwater Research:
Jordan Cove
• Was Designed to Determine Water
Quantity/Quality Benefits of BMP’s
• Monitoring took place over 10 years

39. • More info:
www.jordancove.uconn.edu

40. Findings
Activity Traditional ($) BMP ($)
Cul-de-sac bioretention
1,275 2,183
Driveway (asphalt)/lot 2,800 --
Driveway (paver)/lot -- 7,896
Erosion & sediment
322 625
control/lot
1. To implement BMPs on 100% of the lots in the BMP portion of the subdivision - goal met. Plantings 500 650
2. To maintain post-development peak runoff rate and volume at levels equal to
predevelopment rates. – volume and peak rate goal met Planning and design/lot 401 808
3. To maintain post-development loading of TSS at levels equal to predevelopment rates –
goal not met. Road and curb 23,494 102,500
4. To retain sediment onsite during construction. – goal not met.
5. To reduce nitrogen export by 65% - goal met. Rain gardens/lot 0 575
6. To reduce bacterial export by 85%. – goal not met.
Stormwater collection 7,770 3,600
7. To reduce phosphorus export by 40%. – goal met.
36,562 118,837

41. EDAW

42. • Soils
Can you infiltrate on
• Depth to groundwater
site?
• Liquefaction dangers
• Underground utilities
• Slope
• Contamination

43. Using the Toolkit
Tools that require
infiltration:
– Rain gardens
– Pervious Pavement
Tools that do not
require infiltration:
– Cisterns
– Eco-roofs (or roof
gardens)
– Bioretention planters
– Urban forest
– Stormwater wetland
– Detention basin

44. Gauging Impact of Tools

45. Functions of Tools
Runoff Rainwater Landscaping Infiltration Conveyance WQ
Minimization Capture Treatment
Permeable
Pavement O x x
Bioretention x x O x O
Bioswales x x O O
Stormwater
x x O x x
Planters
Green
O x x
Roofs
Wetlands O x O
Turf
x x O x x
Replacement
Infiltration
x O x
Devices
O Main function Source: Dan Medina, CH2MHill
x Secondary Function

46. General Rule of Thumbs
• Sizing: 4% of catchment
• Vegetation: Native vegetation, drought tolerant,
medium to tall stem height
• Filter Media: Sandy Loam, < 5% fines (clays)
• Pretreatment: Always incorporate pretreatment
separated from system till catchment built out
and veg. established
2/3 Veg Height
80%ile
compliance in
summer
months
Inundation tolerance

47. BMP Sizing Factor Summary
Under-Drain or Infiltration:
IMP Sizing Factors
Flow- Group D: 0.05
Through
Planter
Vegetated/ Group A:
Grassy 0.10 to 0.14
Swale Group D:
0.07 to
0.115 Group A – low runoff potential (<10% clay)
Group D – high runoff potential (>40% clay)
Bioretention Group A: 0.13
Basin Group D: 0.06 • Source: NRCS

52. Next Month’s Forum:
International Green Building Showcase
September 17
Location TBA