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Delaware: Risks & Trends

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Same standard as every other page on this site: every figure below is independently sourced, and figures that vary across sources, or measure genuinely different things, are flagged as such rather than collapsed into one number that looks more precise than the underlying data actually supports.

The Ash Wednesday Storm of 1962

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Dates March 5-9, 1962
Duration parked off coast 3 days, across 5 separate high tides
Deaths (6-state total) 40
Injuries (6-state total) 1,000+
Delaware residents sheltered ~6,000, per contemporary newspaper estimate
Damage (6-state total) Hundreds of millions of dollars (1962 dollars)

Why five high tides mattered more than one big surge

A typical coastal storm floods an area once and recedes. The Ash Wednesday Storm’s defining feature was that it barely moved for three days, so the same coastal areas flooded again and again across five separate high-tide cycles, compounding damage that a single surge, even a larger one, might not have caused.

Sea level rise: a standing risk projected to reshape the coastline

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Current rate vs. global average ~2x the global average rate of sea level rise
Rise over the past century Up to 15 in, per tide gauge records
Increase in tidal flooding since 2000 260%
Mid-century projection 1-1.5 additional feet of sea level rise
2100 projection (high-emissions scenario) 4-6 additional feet
Projected land mass loss to erosion ~11% of the state's total land, at current erosion rates of 3+ ft/year
At-risk properties, Bethany Beach 676 today, projected 814 by 2033
At-risk properties, South Bethany 534 today, projected 855 within 15 years

One of the most severe standing coastal risks on the site

Every coastal state covered on this site faces some degree of sea level rise, but Delaware’s combination of low elevation, flat terrain, and active land subsidence makes its rate of change, roughly double the global average, and its projected land loss among the most severe documented here. This isn’t a single event with a date attached; it’s a compounding, ongoing condition that raises the baseline risk for every future coastal storm.

Sources