STORMWATER GREEN INFRASTRUCTURE AND PLANNING/ZONING BOARDS Source: Center for Watershed Protection, 2007 Southern Tier Central Regional Planning & Development Board Chemung County Stormwater Team
OUTLINE Why do we care about stormwater? What are the new Green Infrastructure stormwater practices for reducing runoff? What is the role of Planning Boards? Upcoming training
Land includes: WHAT IS STORMWATER? Stormwater is water from rain or melting snow that does not soak into the ground. It runs off the surface of the land into storm sewers and ditches. Pervioussurfaces Impervious surfaces
Pollutants WHY IS STORMWATER MANAGEMENT A CONCERN?
WHY IS STORMWATER MANAGEMENT A CONCERN? Stormwater Volume and Flow Increases in impervious surfaces cause an increase in the amount of runoff Flooding Erosion Lack of groundwater recharge causes stream flow to recede to very low levels during dry weather periods $$$
STORMWATER SPDES PERMITS Construction Permit SPDES GP-0-10-001 Must be obtained from NYSDEC by owners and developers of property for projects disturbing 1 acre or more of land surface that result in a direct or indirect discharge to surface waters MS4 Permit SPDES GP-0-10-002 Must be obtained from NYSDEC by municipal government entities that operate Municipal Separate Storm Sewer Systems (MS4s) in designated urbanized areas
STORMWATER CONSTRUCTION PERMIT DETAILS Stormwater Pollution Prevention Plan (SWPPP) prepared Describes control of runoff during construction and afterward, as applicable Notice of Intent Completed after SWPPP is complete Applicant submits to NYSDEC to obtain permit coverage Notice of Termination Applicant submits to NYSDEC to close permit coverage
STORMWATER DESIGN MANUAL CHANGES Newly Revised NYS Stormwater Management Design Manual Focus on the use of low impact site design (reducing runoff quantity) and green infrastructure practices New design process includes planning requirements
RUNOFF REDUCTION CONCEPT Change in design paradigm: New: Reduce runoff generated or manage it at or near the source Old: Treat or control runoff right before it leaves the site or discharges to a water body ( end-of-pipe ) Reduction in Contributing Area To be considered first by the designer Lessen impervious area, reduce footprint, avoid disturbance of natural areas Reduction in Contributing Volume Receive and attenuate runoff within the drainage area through green infrastructure practices Use natural areas and processes for stormwater management
RUNOFF REDUCTION CONCEPT Avoid the Impacts Avoid or minimize disturbance by preserving natural features Reducethe Impacts Achieved by reducing impervious cover and using conservation design techniques Mitigate the Impacts Accomplished by using natural features and runoff reduction practices (green infrastructure)
AVOIDING THE IMPACTS OF STORMWATER RUNOFF Reduce Construction Footprints Restrict clearing and grading Use phased grading Flag areas that should not be disturbed
AVOIDING THE IMPACTS OF STORMWATER RUNOFF Preserve natural hydrology to the extent possible Preserve riparian buffers Locate development in less sensitive areas Fit development to the site conditions (not vice versa!)
REDUCING THE IMPACTS OF STORMWATER RUNOFF Narrower Streets and Sidewalks
REDUCING THE IMPACTS OF STORMWATER RUNOFF Reduce Parking Requirements
REDUCING THE IMPACTS OF STORMWATER RUNOFF Relax height restrictions Lessen roof coverage and building footprint Increased building height results in less impervious area for same amount of floor space Higher densities can be utilized so as to preserve valuable open spaces Photo courtesy US EPA
REDUCING THE IMPACTS OF STORMWATER RUNOFF Open space design Open space design clusters development, reducing construction cost and infrastructure needs Incorporating vegetated open space into the site layout provides: Groundwater recharge Runoff attenuation Nutrient removal
REDUCING THE IMPACTS OF Soil Restoration STORMWATER RUNOFF Convert compacted, dense, poor soil to deep, welldrained soil rich in organic matter
MITIGATING THE IMPACTS OF STORMWATER RUNOFF Promote infiltration into the ground Store stormwater and remove it through evapotranspiration Capture runoff and reuse
MITIGATING THE IMPACTS OF STORMWATER RUNOFF Rain Gardens and Bioretention Manage and treat small volumes of runoff using a conditioned soil bed and vegetation within a shallow depression
MITIGATING THE IMPACTS OF STORMWATER RUNOFF Filter Strips / Buffers Vegetation mitigates the impacts of runoff by Slowing runoff velocity Removing nutrients Storing water in natural depressions Promoting groundwater recharge
MITIGATING THE IMPACTS OF STORMWATER RUNOFF Stormwater Planters Attractive landscape element Use in combination with other practices
MITIGATING THE IMPACTS OF Green Roofs STORMWATER RUNOFF Manage runoff on the roof with soil and vegetation Most applicable in ultra-urban (or ultracold) settings
MITIGATING THE IMPACTS OF STORMWATER RUNOFF Permeable Pavement Porous pavement Permeable pavers Maintenance required
MITIGATING THE IMPACTS OF STORMWATER RUNOFF Stream Daylighting Conversion of piped conveyance to openchannel stream Vegetated Swales Maintained, turf-lined swale designed to convey stormwater at a low velocity, promoting infiltration of runoff
MITIGATING THE IMPACTS OF STORMWATER RUNOFF Disconnection of Impervious Surfaces Roof downspouts are often directly connected to storm drains Runoff volume reduced by allowing infiltration to the ground Same principle applies to roads, driveways, parking lots
MITIGATING THE IMPACTS OF STORMWATER RUNOFF Rain Barrels and Cisterns Reduce runoff and peak flow Must have a use for the water http://www.lid-stormwater.net/raincist/raincist_benefits.htm
MITIGATING THE IMPACTS OF STORMWATER RUNOFF Tree Planting and Tree Pits NYS Stormwater Management Design Manual, 2010
GREEN INFRASTRUCTURE SUMMARY Implement in the following order: Avoid the impacts Reduce the impacts Mitigate the impacts This process may be reviewed by the Planning Board Numerous practices and techniques are available Implementation of Better Site Design and Green Infrastructure approaches requires application, and often revision, of local regulations
MUNICIPAL PLANNING TOOLS Opportunities for addressing stormwater issues Comprehensive plan Blueprint for zoning and other land use regulations to determine the desired land uses and character of the community (NYSDOS) Opportunity to preserve natural features and open space and promote development that minimizes impacts
MUNICIPAL PLANNING TOOLS Smart Growth / Low Impact Development Encourage preservation of natural features even after the land is developed Re-use of vacant formerly developed land Incorporation of green infrastructure features Open space preservation
MUNICIPAL PLANNING TOOLS Subdivision Review / Site Plan Review Include drainage considerations Avoid Reduce Mitigate Use the SWPPP
MUNICIPAL PLANNING TOOLS Zoning Environmental protection overlay districts Bodies of water, wetlands, floodplains, steep slopes, groundwater recharge areas, stream corridors, etc. Incentive zoning Special use permits Performance zoning Area variances
MUNICIPAL PLANNING TOOLS Zoning (continued) Cluster development Housing units are concentrated at a higher density in the most appropriate part of the site Leaves larger areas open and undeveloped to preserve natural features
MUNICIPAL PLANNING TOOLS Local laws Open Space Preservation Wetland Preservation Water Resource Protection
MUNICIPAL PLANNING TOOLS Stormwater local laws Stormwater Runoff Control and/or Erosion and Sediment Control ordinances or local laws Municipalities designated as regulated MS4s are required to adopt Stormwater Runoff Control local laws May be incorporated into other code
MUNICIPAL PLANNING TOOLS State Environmental Quality Review (SEQR) Type I and Unlisted Actions Includes most construction projects over 1 acre Municipality may be lead agency Environmental Assessment Form (EAF) SPDES Construction Permit Use Draft SWPPP If Positive Declaration Environmental Impact Statement (EIS) includes SWPPP
STORMWATER REVIEW PROCESS Pre-submission conference Preliminary plat or sketch plan phase Final plat or site development plan phase Provisions must be made for operation and maintenance of any permanent practices
WHAT S IN THE SWPPP? Erosion and Sediment Control Plan Post-Construction Stormwater Management Plan (if required)
WHAT S IN THE SWPPP? Post-Construction Stormwater Management Plan (if required): Management practices for permanent water quality and quantity controls Operation and maintenance plan Five-Step Planning Process
THE FIVE-STEP PLANNING PROCESS 1. Site Planning: consider conservation of natural areas, reduction of impervious cover 2. Determine Water Quality Volume Enough Runoff Reduction? YES Are quantity requirements met? NO Provide justification 4. Apply stormwater management practices to address remaining water quality volume NO 3. Runoff Reduction by applying Green Infrastructure techniques Completed plan YES 5. Apply volume and peak rate control practices
THE FIVE-STEP PLANNING PROCESS Step 1: Site Planning Know the site: water bodies, wetlands, soils, steep slopes, vegetation, etc. Avoid the impacts: Devise strategies to protect and enhance natural resources
THE FIVE-STEP PLANNING PROCESS Step 1: Site Planning (continued) Reduce the Impacts: Find ways to reduce impervious surfaces
THE FIVE-STEP PLANNING PROCESS Step 1: Site Planning (continued) Applicant should consult with municipality about local codes that promote or limit Better Site Design Resource protection Impervious surface reduction Applicant must show that all reasonable opportunities for preserving natural features of the site have been used to minimize runoff and maintain pre-construction drainage
THE FIVE-STEP PLANNING PROCESS Step 2: Determine Water Quality Volume Step 3: Mitigate the Impacts: Use Green Infrastructure for Runoff Reduction Develop a combination of green infrastructure practices to reduce runoff
THE FIVE-STEP PLANNING PROCESS Step 4: Apply standard stormwater management practices to address remaining Water Quality Volume Stormwater ponds Filtering practices Infiltration practices Stormwater wetlands Open channel swales Step 5: Apply water quantity control practices Channel Protection (1-year) Overbank flood (10-year) Extreme storm (100-year)
SWPPP REVIEW: SPECIAL CONDITIONS Redevelopment Projects Enhanced Phosphorus Removal Requirements (watersheds with phosphorus TMDLs) Steep slopes in drinking water supply watersheds
SWPPP REVIEW Engineering/Technical Review Planning Board generally not in position to comment on technical aspects of SWPPP May retain the expertise of a Professional Engineer and/or Registered Landscape Architect to review technical aspects Liability for failure of technical SWPPP elements lies with the designer
THE CHALLENGES Planning Review Role Review board focuses on planning aspects of SWPPPs Runoff reduction proposals may conflict with local code Recognize that Construction Permit requirements must be met Flexibility and compromise may be necessary to find stormwater management solutions
REVIEW OF THE DESIGN PROCESS Review board should request a narrative description of the entire design process Discuss every step in the process: Avoid Reduce Mitigate Ask for conceptual design sketches Review the rationale for selecting the proposed design over other possible options
REVIEW OF THE DESIGN PROCESS If the Review board believes that justification is inadequate for any element of the design: Request additional justification Re-examine the options available and alternative site layouts MS4s must enforce use of the Green Infrastructure design process
OPERATION AND MAINTENANCE OF PERMANENT PRACTICES Planning Board checks: Maintenance descriptions Identification of party responsible Maintenance agreement(s) and access arrangements Financial responsibility (performance bond, letter of credit, or cash escrow)
PLANNING SUMMARY Municipal planning tools Are local regulations consistent with Green Infrastructure practices? Integrate runoff issues into the project review process The applicant s planning process 5-step design process (Step 1: Site Planning) Rationale behind the selection of practices Operation and maintenance
LEARN MORE: Green Infrastructure and municipal codes evening workshop for municipal board members Fall 2021 On the web: www.chemungstormwater.org www.stcplanning.org Program Areas: Stormwater
FOR MORE INFORMATION PLEASE CONTACT: Steuben County Planning Department Amy Dlugos, Planning Director (607) 664-2267 Amy@co.steuben.ny.us Steuben County Soil & Water Conservation District Jeff Parker, District Manager (607) 776-7398, ext. 3 jgparker@stny.rr.com Southern Tier Central Regional Planning & Development Board Janet Thigpen, Flood Mitigation Spec. (607) 737-5271 jthigpen@co.chemung.ny.us Chelsea Robertson, Planner (607) 962-5092 planner@stny.rr.com Chemung County Stormwater Team (607) 796-2216 dfiorentino@stny.rr.com