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From Climate Hazards to Resilience: Flood Risk in Broad Channel, Jamaica Bay

HIRES Interns: Amy Salinas, Jeremy Lora

Mentors: Niloofar Nejatian, Tasnim Islam, Vasu Mittal

Faculty Advisor: Reza Khanbilvardi

CUNY CREST High School Initiative in Remote Sensing of Earth System Engineering and Sciences (HIRES)

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INTRODUCTION

• Broad Channel is Jamaica Bay’s only inhabited island, home to about 2,370 residents on filled marshland.
• Nearly the entire island lies within FEMA’s 1% annual-chance flood zone, with frequent high-tide flooding and limited drainage.
• Hurricane Sandy damaged approximately 97% of households and temporarily isolated the community.

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DATA & METHODS

Datasets

• Rainfall: gridMET, Broad Channel (1979–2026; 17,365 days).
• Water levels: NOAA CO-OPS, The Battery Station 8518750.
• Flood scenarios: NYC DEP (2024).
• Climate projections: CMRA, Queens County.
• Exposure: NOAA Coastal County Snapshots.

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SOCIAL VULNERABILITY

Table 1. Social and flood-risk indicators for Broad Channel.

FLOOD SCENARIOS

Table 2. NYC DEP stormwater flood scenarios and modelled extent.

IS THE RAINFALL CHANGING?

Figure 2. Annual rainfall and frequency of heavy-rain days, Broad Channel, 1979–2025.

Mean 44.9 in/yr. Totals show no significant trend (+0.78 in/decade, p = 0.31). But heavy-rain days (≥ 1.9 in) are rising: +0.32 days/decade (p = 0.014). Totals are flat; extremes are climbing.

FLOODING AS THE SEA RISES

Figure 3. NYC DEP stormwater flood maps under two  rainfall and sea-level scenarios.

• Under current sea levels, moderate rainfall produces localized flooding in low-lying coastal areas.

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• With higher sea levels and more intense rainfall, flooding becomes deeper, more extensive, and more continuous across Broad Channel and surrounding communities.

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• Sea-level rise alone increases the flooded area by approximately 11% by 2050, even without additional rainfall, because higher tides reduce storm-sewer drainage capacity. Although rainfall intensity increases by 1.7×, the flooded area expands at a much greater rate (Table 2).

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Coastal Flood Exposure

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Figure 4. NOAA Coastal Flood Exposure Mapper: coastal flood hazard composite and wetland potential, Jamaica Bay.

• Nearly all of Broad Channel lies within the 1% annual-chance flood zone, and high tides already reach the ends of some streets.
• The observed mean annual rainfall (44.9 in) closely matches the CMRA baseline.
• The 99th-percentile daily rainfall (~1.9 in) matches the Queens extreme-rainfall threshold, indicating that rainfall intensities projected for late-century conditions are already occurring.

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WHO IS EXPOSED?

10.8%

of Queens land in the

100-year floodplain

~85,000

Queens residents

inside it (3.7%)

>700

Broad Channel buildings

flooding by 2050

$663M

in claims

(11,937 · 1991–2020)

Residents in poverty are over-represented: 4.7% of the county's poor live in the floodplain, against 3.7% of all residents. Two feet of rise arrives ~2055–2080, but 68.6% of the land it floods is natural wetland, a major restoration opportunity.

RESILIENCE PLANS

Grey — >$100M street elevation, drainage upgrades and bulkheads.�Nature-based — marsh restoration at Sunset Cove and living shorelines rebuild buffers.�Policy — CR-1 zoning limits density; Coastal Flood Resiliency zoning enables retrofits.�Community — FloodNet sensors map street-level flooding.�Three paradigms at once:

engineering (streets, bulkheads), social-ecological (marsh, shorelines), and transformative (CR-1 zoning) — yet all assume continued occupation.�Key Trade-Off 

Hard infrastructure dominates and defending in place locks in exposure.

CONCLUSION

• Annual rainfall totals show no significant trend, but heavy-rain days are increasing at +0.32 days per decade (p = 0.014).
• Sea-level rise alone is projected to increase the flooded area by approximately 11% by 2050, even without additional rainfall.
• Higher tides reduce storm-sewer drainage capacity, causing the flooded area to expand faster than rainfall intensity alone.

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REFERENCES & Acknowledgment

• Flood exposure is nearly universal across Broad Channel, with older and lower-income residents disproportionately vulnerable.
• Integrating grey infrastructure, wetland restoration, and living shorelines provides the most durable pathway to long-term resilience.

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A)  Moderate Flood (2.13 in/hr) with Current Sea Levels

B)  Extreme Flood (3.66 in/hr) with 2080 Sea-Level Rise

• Climate Engine/gridMET (1979–2026). Daily precipitation, Broad Channel.
• NOAA CO-OPS. Water levels, The Battery Station 8518750.
• NYC DEP (2024). Stormwater Flood Maps.
• NOAA Coastal Flood Exposure Mapper.
• NOAA Sea Level Rise Viewer.
• NOAA Coastal County Snapshots.
• FEMA National Flood Hazard Layer.
• CMRA Climate Resilience Assessment Tool.

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Methods

• Data collected from Climate Engine, NOAA, NYC Open Data, and CMRA.
• Python and pandas used for cleaning, gap checks, and annual aggregation.
• Trends and correlations evaluated using SciPy; extreme rainfall defined as ≥1.9 in/day.
• DEP scenarios were compared under equal rainfall conditions.
• Observed statistics were validated against the CMRA baseline.

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Figure 1. Location of Broad Channel within New York City and basic street network on Rulers Bar Hassock, Jamaica Bay.

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Acknowledgment: This research project was supported by Pinkerton Foundation, CREST Summer Bridge Program and NSF Grant REU-2447604. The statements contained within this poster are those of the authors and do not reflect the views of the funding agency or the U.S. government.