Green Infrastructure in Action: Examples, Lessons Learned & Strategies for the Future December 2014

Transcription

1 Green Infrastructure in Action: Examples, Lessons Learned & Strategies for the Future December 2014 New York City s Green Infrastructure Plan: Compliance Through Adaptive Management

2 Presentation Overview Genesis of NYC s Green Infrastructure Program Consent Order Obligations for G.I. & Phase I Implementation Lessons Learned & Emerging Issues

3 Dense, Efficient Settlement is Impervious

4 Stormwater Planning: PlaNYC Initiatives 2007 Citywide PlaNYC sustainability initiative included plan to expand use of stormwater BMPs 2008 Stormwater Management Plan Continued focus on source controls Proposed regulatory controls

5 Stormwater Planning: NYC Green Infrastructure Plan Announced September 2010 Proposed controlling first inch of runoff on 10 percent of impervious surfaces in combined areas Incorporated hybrid grey-green approach focused on costeffective projects to control combined sewer overflows (CSOs)

6 G.I. Program Focuses on Combined System Two-thirds of NYC served by combined sewers 216,000 acres of CSO drainage area 7,400 miles of sewers 422 CSO outfalls 27 billion gallons of CSO per year

7 72 % of NYC is covered by impermeable surfaces = Impermeable surfaces = Permeable surfaces

8 G.I. Plan: Opportunities for Green Infrastructure Land Use % of Combined Sewer Watershed New development and redevelopment 5.0% Streets and sidewalks 26.6% Multi-family residential complexes 3.4% Parking lots 0.5% Parks 11.6% Schools 1.9% Vacant lots 1.9% Other public properties 1.1% Expect that 10% capture goal will be met by: - 1/3 New development standards - 1/3 Right-of-way projects - 1/3 Public facilities, parks, and other existing development

9 Consent Order Obligations for G.I CSO Consent Order modification incorporates G.I. targets (10% over 20 yrs) Requires implementation of new stormwater performance standard LTCPs will include baseline credit for CSO volume reductions from G.I. Requires financial commitment for first 5 years of G.I. program ($187M) Adaptive management approach for G.I.

10 G.I. Phased Implementation Timeline Final 3.0% Additional 3.0% Additional 2.5% Initial 1.5%

11 Stormwater Performance Standard Adopted in July 2012 Accompanying guidance issued at same time Intended to reduce peak flow to City sewers during rain events Applies to new development and alterations in combined areas

12 Order Includes Contingency Plan Option G.I. targets spaced every 5 years (first deadline is 2015) If any target is missed, DEP can submit contingency plan within 6 months Plan must specify grey and/or green projects to address shortfall, with schedule

13 Implementation in Phase I First phase ( ) requires 1.5% penetration rate Provides for program development and slow initial ramp-up DEP s Office of Green Infrastructure & interagency partnerships DEP works closely with Departments of Parks, Design & Construction, and Economic Development to execute and maintain projects Design standards

14 G.I. Design Standards Detailed engineering designs for several types of G.I. installations available on DEP website Streamlined designs facilitate efficient contracting and implementation Received Excellence in Design Award from NYC Public Design Commission in July 2013

15 Pilot Projects 30+ G.I. source controls constructed and monitored since 2010 Tree pits, blue & green roofs, subsurface detention, porous pavement, bioretention facilities Remote monitoring equipment measures flows at regular intervals Collect data on runoff rates & volume, water & soil quality, typical maintenance requirements 3 neighborhood-scale projects studied under Consent Order, covering 63 acres of tributary area

16 Priority Areas

17 Priority Areas Area-wide contracts for Priority CSO Tributary Areas Criteria include: CSO volume & frequency; outfalls in proximity to public access locations; presence of other CSO-reduction projects Allows saturation of G.I. practices & realization of efficiencies in design and construction Standardized designs and procedures facilitate area-wide strategy

18 Right-of-Way Bioswales Placed in publicly owned ROW installations bid out at a time, with 6 month construction timeline

19 Public On-Site Retrofits DEP works with other City agencies to identify sites for G.I. retrofits that meet the agencies program goals Sites must have suitable infiltration conditions and be free of hazardous materials, underground vaults, and existing stormwater systems

20 Public-Private Partnerships DEP funding up to $5M for construction of 10 G.I. playgrounds per year over 4 yrs At P.S. 261, Trust for Public Land engaged 4 th graders on conceptual design Completed project manages 23,000 square feet of impervious area & 500,000 gal stormwater per year

21 G.I. Grant Program DEP initiated grant program in 2011 to strengthen public-private partnerships & public engagement Online application process Extensive public outreach to interested stakeholders Consent Order requires commitment of additional $3M in G.I. grants by 2015 By end of 2013, DEP had committed $11.5M to 29 private property owners for G.I. projects

22 Implementation: Tracking Compliance Annual report describes completed projects and action plan for following year DEP also launching web-based GIS Project Map to track all projects, public & private Stormwater performance standard tracked through sewer connection certifications Total area managed through G.I. as of 2013: 28.9 acres Total area planned through the end of 2014: acres 1.5% target requires estimated 1180 acres

23 Lessons Learned Implementation challenges Existing urban street conditions Geologic and soil conditions (e.g. high bedrock, clay soils) High groundwater tables Utility conflicts Contaminated soils Importance of design standards Interagency coordination strategy is effective G.I. is generally popular

24 Emerging Issues Translation to LTCP volume goals & long-term monitoring Contingency plan process Documentation of G.I. cobenefits Application in MS4 areas O&M

25 Paerdegat Detention Facility Staten Island Bluebelt Catch Basins Enhanced Tree Pit

26 Questions? The NYC Green Infrastructure Plan and other documents referenced today can be viewed at and downloaded from :

27 Carrie Noteboom, Senior Counsel Environmental Law Division New York City Law Department 100 Church Street New York, NY