Gowanus BID · Urban Design Strategies and Case Studies

GO-Wanus Green: Beyond Static Planning

A community-supported, agent-based urban forestry roadmap for the Gowanus BID.

Team 3: Liu, Wang, Zhang, Yin, Yao

00 · Introduction

What Can a Green Future Bring?

The gap

Ecological Pressure

Street trees in Gowanus are characterized as young, sparse, and low in diversity. Narrow sidewalk design not only limits tree growth, but also damages nearly 50% of tree-adjacent sidewalks.

Gowanus context map showing surrounding neighborhoods and block-level canopy pattern

35%

Trees under 6" DBH

36%

Native species only

~50%

Sidewalks under 10 ft

15%

Moderate flood risk zone

The Future

Resilient & Livable Streetscape

The intervention targets streets under the most ecological pressure by adding ~176 trees in areas with low canopy and highest stormwater flood risk, and widening high-conflict corridors to support tree growth.

The redesigned streetscape creates a safer, more comfortable pedestrian experience, encouraging longer dwell time and stronger local retail activity.

Narrowed roadways reduce vehicle accessibility within the community, lowering gas emissions and improving pedestrian friendliness.

48–172%

Retail range (lit. streetscape)

+83.1%

Pedestrian dwell (vs. S0)

+13.8%

Ecological benefit signal

−10.7%

Vehicle trips — explicit trade-off

Research spine

Motivation & context

Insights

As a former industrial community transitioning to residential mixed-use, creating a pedestrian and ecologically friendly environment is essential to attract new residents. However, Gowanus's industrial legacy, fragile ecological system, and budget limitations all make its green transformation challenging.

Click each card to view the problem breakdown.

Spatial transformation

Transformation

To transform current conditions into the proposed green corridors, we developed a 2-step tree planting strategy that prioritizes ecologically vulnerable streets.

02 · Intervention strategy

Intervention scenarios

Click a scenario to view the corresponding spatial intervention. Planned tree locations are predefined to maximize ecological benefits.

Legend

Original Trees· 0Newly Planted Trees· 0

Sidewalks Change (ft)

0 – 2 ft2 – 4 ft> 4 ft
Scenario 2
100%
Loading OSM + GAMA data...

S2 Full: all S1 trees plus wider sidewalk corridors (violet) and additional canopy coverage.

02b · Planting design

Species and Planting Strategies

Planting strategy

🌊

Prioritize flood-prone, low-canopy streets to improve shade, stormwater capture, and comfort.

📐

Match species to sidewalk width, soil volume, and street exposure for healthier growth.

🪨

Use expanded tree beds and permeable paving to support roots and reduce runoff.

⚠️

Avoid overrepresented species such as London Plane, Honey Locust, and Ginkgo to improve biodiversity.

Simulation methodology

Prediction

We use GAMA to run spatially-explicit agents on Gowanus streets. Commuters, random locals, scenic visitors, joggers, and drivers each carry distinct routing and dwell heuristics, feeding crowding, shade, and Linger-based retail exposure for scenario comparison.

Expand for detail

GAMA is an easy-to-use open source modeling and simulation environment for creating spatially explicit agent-based simulations. It allows us simulate how people and vehicles move through streets and public space. We use it here because the project must compare interventions under behaviorial and spatial constraints, where GAMA can provide scenario testing outputs with transparent, repeatable logic.

Live demo

Agent behavior

Behavioral Overflow

Where indirect behavioral effects accumulate — pedestrian rerouting toward shade and vehicle congestion from narrowed corridors.

Pedestrians' Logic Flow

Gowanus Trees: Simulation Overview and Process Chain

Vehicles' Logic Flow

Gowanus Vehicles simulation overview

Scenarios & impact

Outcome & Prediction

Prediction outputs are grouped into numbers first, charts second, and spatial impact last. This keeps the section readable and professional.

Interactive chart

S0 vs S2 — pollutant trajectories (line race)

Apache ECharts animation: O₃, NO₂, SO₂, and PM over the modeled horizon. Served from your exported line-race.html in public/.

Open full page

Pedestrian Vitality (S2 vs S0)

Pass-through flow

Adding trees and space increases overall pedestrian movement drastically compared to baseline.

+41.5%

Average dwell time

Time spent lingering rises from ~74s to ~135s.

+83.1%

Vehicle Trade-offs (S2 vs S0)

Completed trips

Completion rate drops from 90.8% to 81.1% due to narrowed road bottlenecks.

-10.7%

Emissions

Reduced vehicle miles traveled naturally reduces localized gas and PM emissions.

-14.9%

Ecological ROI

Up to 21.4% increase in 20-year eco-benefit under S2 vs. baseline—driven by combined hardscape and planting interventions.

Figures are indicative of coupled green–infrastructure benefits; calibrate to your i-Tree runs and BID geodata.

Economic data

NYC DOT complete-street and corridor redesigns have been associated with roughly 48–172% potential retail sales lift in published streetscape studies—context and lease mix apply.

Use with local sales tax / POS panels where available to localize the range for the BID.

Stakeholders & delivery

Consensus & Action

A 9-month approval pipeline aligning GCC, BID, and DOT authority with on-the-ground stewardship.

Simulation as a Negotiation Platform

Our GAMA model is not just a tool; it is a common language. By identifying gap sites, we achieve canopy goals while respecting local parking needs and avoiding rigid DOT/Parks friction points.

Estimated Budget

Tree Planting$580,800
Sidewalk Widening$250K – $420K
Total Capital Required~$830,000

GCC Technical Review

↗ open

9-Month Approval Pipeline

Click any timeline card

1
2
3
4
5

Sources & citation

Reference

Websites, tools, and local datasets used across this portfolio.

Organizations

Gowanus Canal Conservancy (GCC)

Stakeholder reference used in the approval timeline.

Gowanus Improvement District (BID)

BID participation and engagement reference.

NYC Department of Transportation (DOT)

Pilot permitting and streetscape policy context.

New York City Department of Parks & Recreation

Urban forestry coordination and tree stewardship context.

NYC Department of Environmental Protection (DEP)

Stormwater and environmental infrastructure context.

Platforms & Tools

OpenStreetMap

Basemap tiles and OSM embed are used in map modules.

Apache ECharts

Line-race chart runtime for pollutant trajectories.

QGIS

Data processing and spatial analysis tool for preparing GIS layers.

GAMA Platform

Agent-based simulation framework referenced in methodology.

Datasets

BID boundary and geometry

Local dataset from public/data_from_gama.

Canal geometry

Local dataset from public/data_from_gama.

Tree inventory baseline

Local dataset for current tree distribution.

Scenario trees (full/new) and street change

Scenario datasets paired with bid_trees_new.geojson and street_change.geojson.

Academic Papers

Nowak, D. J., Crane, D. E., & Stevens, J. C. (2006). Air pollution removal by urban trees and shrubs in the United States. Urban Forestry & Urban Greening, 4(3-4), 115-123.

DOI

Shetty, N. H. (2023). Estimating stormwater infiltration and canopy interception for street tree pits in Manhattan, New York. Forests, 14(2), 216.

DOI

Westfall, J. A., Nowak, D. J., Henning, J. G., Lister, T. W., Edgar, C. B., Majewsky, M. A., & Sonti, N. F. (2020). Crown width models for woody plant species growing in urban areas of the U.S. Urban Ecosystems, 23(4), 905-917.

DOI

Mailloux, B. J., McGillis, C., Maenza-Gmelch, T., Culligan, P. J., He, M. Z., Kaspi, G., Miley, M., Komita-Moussa, E., Sanchez, T. R., Steiger, E., Zhao, H., & Cook, E. M. (2024). Large-scale determinants of street tree growth rates across an urban environment. PLoS ONE, 19(7), e0304447.

DOI

Rosenzweig, C., Solecki, W., & Slosberg, R. (2006). Mitigating New York City's heat island with urban forestry, living roofs, and light surfaces (Final Report 06-06). New York State Energy Research and Development Authority.

Report PDF

Nowak, D. J. (1996). Estimating leaf area and leaf biomass of open-grown deciduous urban trees. Forest Science, 42(4), 504-507.

DOI