The Numbers at a Glance
Key statistics from official sources paint a clear picture of Nantucket's coastal challenges.
Sources: NOAA Tide Gauge Station 8449130; Town of Nantucket Coastal Resilience Plan (2021); Massachusetts Coastal Zone Management
Sea Level Rise: Past, Present, Future
NOAA has tracked water levels at Steamboat Wharf since 1965. The data shows a clear trend - and the town has adopted NOAA's "high scenario" projections for all planning purposes.
NOAA Projections for Nantucket
| Year | Projected Rise | What It Means |
|---|---|---|
| 2024 | 8.7 inches | Current conditions |
| 2040 | 1.15 feet | Significantly more frequent flooding |
| 2060 | 2.36 feet | Daily high tide flooding in low areas |
| 2080 | 4.36 feet | Major infrastructure impacts |
| 2100 | 6.66 feet | Transformative change |
Source: NOAA 2022 High Sea Level Rise Scenario, adopted by Nantucket Select Board for all town planning
Downtown Flooding: Easy Street's Story
The cobblestones of Easy Street - the heart of Nantucket's downtown waterfront - tell the story of rising seas better than any chart. What was once a rare occurrence is now routine.
Flood Days Per Year at Easy Street
For Visitors
During high tides - especially during full and new moons or when combined with onshore winds - downtown areas around Easy Street, Straight Wharf, and Commercial Wharf may experience temporary flooding. Check NOAA tide predictions if you're planning waterfront activities. The flooding typically recedes within a few hours as the tide falls.
Coastal Erosion by Location
Nantucket has some of the highest erosion rates in Massachusetts, ranging from less than 1 foot to over 12 feet per year depending on location. The south shore and western beaches are most affected.
Annual Erosion Rates
Source: Massachusetts Coastal Zone Management; erosion rates measured since 1970 via MORIS
Madaket
The west end has Nantucket's highest erosion rate. Over the past three years, coastal banks have retreated 19 feet, threatening homes and Madaket Road.
Sconset Bluffs
Iconic shingled cottages sit atop bluffs under assault for 15+ years. Several homes have been relocated or lost to erosion.
Downtown/Easy Street
High tide flooding has become routine downtown. The town is investing $2.5M in flood mitigation for this area.
Cisco Beach
Popular with surfers, this south shore beach sees significant annual sand loss. 16-foot swells have removed up to 20 feet of shoreline at once.
The Four Challenges
The 2021 Coastal Resilience Plan identified four interconnected hazards facing Nantucket:
Sea Level Rise
8.7 inches since 1965, projected to reach 6.66 feet by 2100
High Tide Flooding
"Nuisance flooding" now occurs 75+ days per year downtown
Coastal Erosion
2-25 feet per year lost at various locations around the island
Groundwater Rise
Threatens septic systems and the island's sole drinking water aquifer
Infrastructure and Buildings at Risk
The 2020 Coastal Risk Assessment quantified what's at stake through 2070 if no action is taken:
A 2015 WPI study identified 24 critical infrastructure elements in the downtown flood zone, including the Sea Street Pump Station and Candle Street Substation, which were flagged as needing "immediate repair" due to flood vulnerability.
Economic Reality
The financial stakes are enormous - but so is the cost of inaction.
if no action is taken
over 15 years
Property Value Impacts
Climate risk is already affecting real estate. In recent years:
- A home valued at $1.9 million sold for $200,000 after severe erosion threatened the property
- Another property lost 70 feet of shoreline in just weeks, causing the price to drop from $2.3M to $600K
- Homes in high-erosion areas have sold for 74-90% below what comparable non-threatened properties would bring
Source: News reports from Fortune, Axios, Boston Globe (2024)
What Nantucket Is Doing
The town isn't waiting. A comprehensive 286-page Coastal Resilience Plan was finalized in 2021, and implementation is underway.
Key Initiatives
| Coastal Resilience Plan | 40 projects over 15 years |
| Easy Street Flood Mitigation | $2.5 million allocated; design completed 2025 |
| Washington Street Framework | Elevated coastal barrier, multi-use path, stormwater wetlands |
| Coastal Resilience Districts | Approved by voters May 2024 |
| Committed Funding | $14 million to date |
The town has hired a dedicated Coastal Resilience Coordinator (Leah Hill) and established the Coastal Resilience Advisory Committee, which meets twice monthly to guide adaptation efforts.
What This Means for Your Visit
- Check the tides before planning waterfront activities - especially during full/new moons
- Beach conditions change - erosion may have altered your favorite spots since your last visit
- Historic downtown flooding is temporary - it recedes with the tide, typically within hours
- The island is adapting - you may see construction related to resilience projects
- Nantucket remains beautiful - these challenges haven't diminished its charm or attractions
Sources & Further Reading
All statistics on this page are drawn from official sources:
- NOAA Tide Gauge Station 8449130 - Sea level measurements since 1965
- Town of Nantucket Sea Level Rise Page - Official projections and flood data
- Town Coastal Resilience Page - Plan overview and current projects
- WPI Storm Surge Study (2015) - Infrastructure risk assessment
- Coastal Resilience Library - Full reports and studies
- Inside Climate News Coverage - 2025 comprehensive article