Mapping Flood Defense Infrastructure

Mapping Flood Defense Infrastructure in Tribeca, SoHo, Civic Center and Little Italy

Planning Methods | Graduate School of Architecture, Planning and Preservation Camila Botero (cb3785), Lance Mikhail Punay (lrp2143), Inneke Rizky Rachmawati (ir2453), & Catharina Utami (cku2103)

December 2022

Contents History and Background Research Question Methodological approach Data Collection and Analysis Results and Findings Final Recommendations

History and Background Research Question Methodological approach Data Collection and Analysis Results and Findings Final Recommendations

Located in Lower Manhattan, Tribeca, Soho, Civic Center and Little Italy is a neighborhood whose name is an acronym for “Triangle Below Canal” Bounded by Canal Street in the north and Lower Manhattan in the south, the neighborhood consists of over 80% of commercial activities.

The waterfront development area is part of the Hudson River Park which includes Pier 25, 26, 34, and Tribeca Upland.

Figure 1 (left) . Tribeca, SoHo, Civic Center and Little Italy Neighborhood Boundaries by Neighborhood Tabulation Area (NTA)

History and Background Research Question Methodological approach Data Collection and Analysis Results and Findings

In 2020, the total population in the study area neighborhood had increased by nearly 5%. This neighborhood has a density of 49.2 people per square mile, which indicates a high-density and populous area.

Compared to New York City’s Median Household Income in 2020 ($66.907), Tribeca's Median Household Income is almost three times higher ($ 200.000).

Final Recommendations

The neighborhood has 11.342 housing units with an average household size of 2,26 people per square mile.

The population of 30-34 years and 35-39 years together had the highest percentage of 33%. This percentage is also higher than the citywide.

Compared to Citywide data, the study area neighborhood has a significantly low rate of residents below the poverty level. Citywide and Tribeca percentage of residents below the poverty level is 17,3% and 2% respectively.

The most dominant race in the study area is White, which accounted for two-thirds of its population and doubled the Citywide percentage. The Asian, Hispanic, and Black percentages, are 12%, 11%, and 6%, respectively, lower than the Citywide percentage.

Figure 2. Study Area Neighborhood Zoning District

Research Question Methodological approach Data Collection and Analysis Results and Findings Final Recommendations

Purpose: understand the current level of preparedness of the study area Neighborhood (Tribeca, SoHo, Civic Center and Little Italy) against the risk of projected midterm sea level rise and flood induced by climate change.

The preparedness against climate-related hazards such as sea level rise and flood is defined from the state of current infrastructure relevant to climate resilience, planning policies in place, and mitigation plans in the study area.

What are the available flood defense infrastructures that can prevent direct damage to the study area?

Methodological Approach Data Collection and Analysis Results and Findings

Literature Review Taking into account a report written by Rebuild by Design and One Architecture & Urbanism: Toward a Rainproof New York City: Turning the Concrete Jungle into a Sponge.

Final Recommendations

Conveyance systems: Drainage pipes, streets, and blue belts that direct the water flow to be retained or detained by permeable surfaces

Detention systems: Approach to store water temporarily during a high precipitation event, such as green roofs, park space, bioswales, berms, sunken courts, and sunken green space.

Retention systems: An area that stores water on a more permanent basis, like ponds, reservoirs, and streams

Building protection: Structures or elements to protect the built environment such as seawalls, revetments, bulkheads, breakwaters, subway protection, tunnel protection, power plant protection, and floodproofing.

Methodological Approach Data Collection and Analysis Results and Findings Final Recommendations

Quantitative Method

Qualitative Method

Geospatial Analysis: Multiple Criteria Decision Analysis

Interviews

Methodological Approach Data Collection and Analysis

Quantitative Method Geospatial Analysis: Multiple Criteria Decision Analysis

Results and Findings Final Recommendations

Decision Layers

Conveyance systems • NYC Sewer system Detention systems • NYC Open space • Street tree Census Retention systems • NYC Hydrography Building protection • NYC Hazard Mitigation plans Flood Hazard • Sea-Level rise and Floodplain Projection • Waterfront access Map New York City Spatial Data • US Census Bureau by NTAs • NYC Census Blocks • Borough Boundaries

Qualitative Method

Methodological Approach Data Collection and Analysis

Interviews

Results and Findings Final Recommendations

Interviewees

Conor Allerton • Director of Land Use and Housing - New York City Council (District 1 ) Thaddeus Pawlowski • Managing Director at the Center for Resilient Cities and Landscape • Adjunct Associate Professor at Columbia University Graduate School of Architecture, Planning and Preservation Zoe M. Kim • Environmental Educator of Hudson River Park

Data Collection and Analysis Results and Findings

An example of weighted strategies sourced from Conor Allerton

Euclidian distance

Conveyance systems NYC Sewer system

x3

Euclidian distance Kernel density

Detention systems Green open space Street tree Census

x2

x1

Euclidian distance

Retention systems NYC Hydrography

Euclidian distance

Building protection NYC Hazard Mitigation

x4

Flood Hazard NYC Flood plain Sea level rise

x4

+

+

+ -

x1

Ranked and Weighted Maps for 2020 and 2050

Multiple Criteria Decision Analysis

Final Recommendations

Data Collection and Analysis

Decision Layers & Map Algebra (2020)

x3

x2

+ Conveyance Systems NYC Sewer system

x2

+ Detention Systems NYC Green Open Space

+ Detention Systems NYC Street Tree Density

x4

+

x4

Building Protection NYC Hazard Mitigation

Retention Systems NYC Hydrography

1 2 3 4 5

Flood Hazard Stormwater (2020)

Flood Hazard Sea Level Rise (2020)

Data Collection and Analysis

Decision Layers & Map Algebra (2050)

x3

x2

+ Conveyance Systems NYC Sewer system

x2

+ Detention Systems NYC Green Open Space

+ Detention Systems NYC Street Tree Density

x4

+

x4

Building Protection NYC Hazard Mitigation

Retention Systems NYC Hydrography

1 2 3 4 5

Flood Hazard Stormwater (2050)

Flood Hazard Sea Level Rise (2050)

GIS (Map Results)

Results and Findings Final Recommendations

2020 Multicriteria decision map

-3

19

35

2050 Multicriteria decision map

Results and Findings Final Recommendations

The qualitative study conducted provide insights of other initiatives which contributed in reducing the risk of flood to the study area.

The Tribeca Habitat Enhancement Project works on the restoration of the Eastern oysters (Crassostrea virginica) to the Hudson River Estuary.

Oyster reefs naturally perform storm surge attenuation, the process by which complex structures catch and reduce wave energy during storms to reduce wave energy that can prevent flood waters from entering the city’s streets.

The City officials also facilitated Zoning Amendment for Coastal Flood Resilience which aims to incentivize retrofitting through zoning bonuses and grants, while making sure property owners can financially implement resiliency measures to their buildings.

Community engagement and participation is key to achieving better outcome to the resiliency initiatives.

Figure 3. Oyster Gabion Installment, Hudson River Park (2021)

Final Recommendations

The findings of the study provide further insight about flood-defense infrastructure into the surrounding areas that will be impacted by the sea level rise and storm surge in long-term projections from 2020 and 2050. The spatial model resulting from this research could also be replicated in other neighborhoods across the city.

Control and mitigation planning as well as advance and preventative planning should go hand in hand with participatory planning .

The map results add as a point of consideration for future tenants and property owners in the decision-making process occurring during determining the flood insurance.

Conveyance and Building Protection infrastructures play a significant role in mitigating the flood. Other than that, flood prone areas could also adopt the nature-based flood preventive measures such as putting oysters in water ecosystem as the breakwaters.