1. Better Site Design Sustainability & Stormwater
Shohreh Karimipour, P.E.
NYSDEC

2. Presentation Outline Principles Better Site Design
(LID, Sustainability, Environmental Design,
Green Infrastructure)
Categories
Preserve Natural Features
Reduce Impervious Cover
Better Integrate Stormwater Treatment
Principles
Specific Practices

3. An approach to development design
Better Site Design
An approach to development design
that seeks to:
Preserve undisturbed areas
Conservation Design

4. An approach to development design
Better Site Design
An approach to development design
that seeks to:
Reduce impervious cover
Roads
Parking lots
Driveways

5. An approach to development design that seeks to:
Better Site Design
An approach to development design that seeks to:
Use pervious areas for stormwater treatment

6. Conventional Site Design Good Drainage Paradigm
Collect Concentrate Convey Centralized Control
Good Drainage Paradigm
Credit: HWG

7. Treatment Train Approach
Rain Garden
Treatment Train Approach
Bioretention Cell
Flow Path
Grass Swale
Grass Filter Strip
Bioretention Cell
Storm Drain System
Credit: HWG

8. NYS Standard Practices
NYS Stormwater Design Standard
Overlap ( )
with BSD or LID Practices O

9. BSD Category one Avoid the Impacts: Preserve Natural Features and Use Conservation Design

10. Preservation of Undisturbed Areas
Delineate on plans / in the field
Place in permanent conservation:
Undisturbed forest
Native vegetation
Stream corridors
Wetlands
Natural terrain – hydrology

11. Preservation of Buffers
Delineate buffers
Protect during:
Design
Construction
Home occupancy
Non-structural stormwater infiltration
Consult/amend local codes
US Forest Service 1

12. Preservation of Buffers

13. Reduction of Clearing & Grading
Establish Limit of Disturbance for:
Buildings
Roads
Utilities
Wastewater
Stormwater
Use site foot-printing
Limit mass grading
Use open space or cluster development

14. Locate Sites in Less Sensitive Areas
Locate development to avoid:
Erodible soils
Floodplains
Steep slopes
Wetlands
Mature Forests
Critical habitat
GCSWCD 1

15. Open Space Design Use smaller lot sizes Reduce impervious cover
Provide more undisturbed open space
Protect water resources

16. Open Space Design Preserves conservation areas
Preserves natural hydrology
Saves costs
reduces grading
reduces infrastructure
Successful Examples

17. BSD Category Two Reduce the Impacts: Reduce Impervious Surfaces

18. Roadway Reduction Design according to density and traffic demand
Minimize roadway lengths
Minimize roadway widths
Consult / amend local codes
Use AASHTO* guidelines
Use alternative road patterns

19. Driveway Reduction Shared driveway Planning Board
Provide Model Shared Driveway Agreement to applicants
Alternative materials
Shorter setbacks
Encourage shared driveways
Use Model Shared Driveway Agreement
Encourage pervious materials on pull offs for emergency

20. Minimize Cul-de-Sacs
Town of Wappinger § requires cul-de-sacs be circular with no center island
REVISE CODE to require developers demonstrate no alternative to cul-de-sac; minimized paved area

21. What about New York State Highway Law?
New Town roads Right-of-way = 49.5 feet
If not, must petition Commissioner of Transportation
Recommend: Keep minimum – also needed for
stormwater and snow removal.
But limit pavement to travel-way.

22. Sidewalk Reduction Use alternative designs
Design on one side of street only
Use alternative surfaces

23. Building Footprint Reduction
Benefits:
Reduces impervious cover & pollutants

24. Parking Reduction
Compact car spaces
Minimal stall dimensions
Efficient parking lanes
Parking decks
Porous paving in overflow
Eliminate unneeded spaces

25. BSD Category 3 Manage the Impacts: Better Integrate Stormwater Treatment

26. Open Vegetated Channels
Convey & treat runoff
Natural drainage paths
Properly designed & constructed channels
On certain sites use in street right-of-way

27. Vegetated Buffer/Filter Strips
Treat & control runoff with:
Forested areas
Stream buffers
Vegetated filter strips

28. Tree Planting In stormwater management practices (where appropriate)
Plant trees:
In stormwater management practices (where appropriate)
In landscape plans
Revegetate buffer areas . . .

29. Infiltration O
Use permeable pavement/pavers where site conditions are appropriate:
Pedestrian areas
Overflow parking
Residential driveways
Green Streets

30. Ecosystem function and service:
Water retention and Storage

31. Stream Daylighting for Redevelopment
Increases aesthetics
Improves water quality
Prevents flooding – increased storage
Improves in-stream habitat
Increases public use
Increases property values
Sunlight

32. Redevelopment Projects
Chapter is part of Design Manual (Chapter 9)
Permit coverage in 5 business days Public Noticed
Application Criteria
An already impervious area reconstructed, and
There is inadequate space for controlling stormwater runoff, or
There are physical constraints on the site
Sizing Criteria
25% reduction in impervious area
Treat 25% WQv with standard practice
Treat 75% of WQv with Alternative Practices
Combination of all the above
Performance Criteria
Alternative Practices (Cisterns, Rain gardens, Green roofs, Stormwater planters, Porous and permeable pavements, Select proprietary products )

33. Cisterns 33

34. Cisterns Applications Limitations
Capture and store stormwater runoff for reuse or irrigation
Limitations
Maintenance
Water use management
Cold Climate
Community Acceptance
Sizing based on the contributing area:
Vol = WQv * 7.5 gals/ft3

35. Rain Gardens 35

36. Rain Gardens Applications Limitations
Manage and treat small volumes of runoff
Use conditioned planting soil bed and planting material
Filter runoff stored within a shallow depression
Limitations
Steep slopes
Compacted and clay soils
Sheet / shallow concentrated flow
Roof drain downspout < 1,000 square feet
Heavy tree cover or root systems
Sizing based on WQ volume reduction

37. Green Roofs 37

38. Extensive Green Roof
Intensive Green Roof

39. Green Roofs Applications Limitations
Reducing total annual runoff volumes  
Insulation from the heat and cold, energy conservation
Reduce the urban heat island effect
Creates habitat, aesthetically pleasing  
Limitations
Damage to or failure of waterproofing
plant survival
Maintenance
Sizing based on WQv reduction, soil engineering, evapotranspiration

41. Stormwater Planters 41

42. Stormwater Planters Applications Limitations Sizing
On-site soils, high GW table not suitable for infiltration 
Reduction of discharge volume, velocity from impervious areas
Aesthetic landscape element and micro-habitat
Limitations
Not designed to treat roadway runoff
Overflow needs to be directed to a
secondary treatment system
Sizing
WQV based on surface area, depth
Of soil medium, hydraulic conductivity

43. Permeable Paving 43

44. Permeable Paving Porous Pavement 1
Photo Copyright 1999, Center for Watershed Protection 1

45. Permeable Paving Permeable Pavers Applications Limitations Sizing
low-traffic areas
overflow parking
Residential single family home
GW recharge
Limitations
suitability of the site grades
Subsoils
Drainage characteristics
Groundwater conditions
Sizing
based on surface area
Photo Copyright 1999, Center for Watershed Protection 1

46. Summary:
Improve development projects & communities with Better Site Design
Preserve undisturbed areas
Reduce impervious cover
Use pervious areas for stormwater treatment
Achieve a marketable, cost-effective product

47. Questions? Shohreh Karimipour, P.E. sxkarimi@gw.dec.state.ny.us
(518)
Angus Eaton, P.E.
(518)