Space available for creation of new bioswale

NYC sidewalk “rain garden” +/- 1000 SF on any given street

VS.

1.5 acres of continuous open space

PlaNYC Initiatives

- achieve 30% tree canopy citywide

- implement a multi-layered strategy for flood resilience

- maximize climate infrastructure on city-owned property

- create accessible, connected open public spaces

- reduce sewer overflows by up to 4 billion gallons citywide by 2045

City-wide Planning Context

Key public resilience projects shown in the map represent city-wide planning efforts to enhance the resilience of Lower Manhattan since Hurricane Sandy.

In Tribeca, the elevation is relatively low around Canal Street, at around EL 9.5ft. This contributes to the area-wide vulnerability to flooding.

Image source: Lower Manhattan Climate Resilience Study 2019

Green Infrastructure for Stormwater

Rotary Park Opportunities

Increased Vegetation in the park can provide aesthetic beauty and shade while also serving as natural filters, helping to reduce dust and improve air quality, and reduce urban heat island effects.

Sub-surface stormwater detention systems can be integrated beneath the park for storage and management of stormwater runoff.

Bioswales within the park design further enhances its visual appeal while promoting stormwater infiltration and evapotranspiration, contributing to the overall sustainability and resilience of the park’s ecosystem.

At the Rotary: approximately 400,000 gallons of water runoff can be avoided in a 4-inch rainfall/cloudburst event. Furthermore, any water present on site will be filtered of pollutants before moving into city infrastructure/river.

At the Rotary: 120 tons of soil organic carbon (representing 450 tons of carbon dioxide) can be created over time, converting auto emissions into biomass through photosynthesis and creating a “breathable zone” around the rotary

At the Rotary: shade and evapotranspiration from new trees can reduce temperatures by up to 9 degrees compared to the existing spaces, which can reduce energy usage in surrounding buildings

NYC Department of Design and Construction: Guidelines for High Performance Infrastructure

EDC Climate Adaptation Toolkit

Street improvement precedents in NYC: DOT + Parks NYC + BID

Responsibility areas

Rotary as Sponge in Three Phases

1: Sponge at Rotary Center
30% greenscape
70% hardscape
EASY

2: Sponge at Perimeter
60% greenscape
40% hardscape
MEDIUM

3: Permeable Pavement at Roadway
100% greenscape
0% hardscapae
HARD

Rotary as Public Space in Five Phases

Phase 1: Laight Street
Goal: Improve entry from NE (SoHo, Canal St.)
EASY

Phase 2: Hudson Street
Goal: Significant increase of greenery to offset heavy traffic; break up long block exposure to Rotary traffic; significant increase of public spaces and amenities
MEDIUM

Phase 3: Varick Street Part 1
Goal: Significant increase of greenery to offset heavy traffic; improve entrance to pedestrian bridge
MEDIUM

Phase 4: Varick Street Part 2
Goal: Replace NYPD parking with bioswale, plantings; increase public space and amenities
DIFFICULT

Phase 5: Ericsson Place
Goal: Replace NYPD parking with playground for nearby preschools
VERY DIFFICULT

The Goal

Transform the Rotary into an environmental asset, a public amenity, and a piece of vibrant green infrastructure

ENVIRONMENTAL RESILIENCE
Phased reduction/elimination of hardscape surfaces will:
- Reduce runoff
- Collect water in cloudburst or storm surge scenario
- Reduce heat island
- Improve carbon sequestration and improve dismal air quality of area

IMPROVED PEDESTRIAN EXPERIENCE
Improvements to streetscape:
- Redesign and/or relocate existing fence to increase public space
- Replace sidewalk parking with green/bioswale to mitigate sidewalk runoff
- Add public seating
- Add new trees
- Public art
- Playground spaces for local schools adjacent to property

Community engagement:
- Planting new trees
- Public art opportunities
- Sense of ownership and pride to a currenlty unloved and unfriendly space

Improved connectivity:
- Rethink existing pedestrian footbridge (non-ADA accessible) to connect Laight and Hudson to Varick, Canal and 6th Avenue