US Army Corps of Engineers
North Atlantic Division

Projected Coastal Flood Increases (2018 to 2118)

Animated graphic showing graphs for Projected Coastal Flood Increases from 2018 to 2118Relative Sea  Level Change for USACE Intermediate Scenario graph

  1. 2018
  2. 2038
  3. 2058
  4. 2078
  5. 2098
  6. 2118

Extreme water levels chart

(Annual Exceedence Probability):

  1.  99 percent flood: with a 99 percent chance of being equaled or exceeded in nearly every year, often referred to as the annual storm. (Water level increases from less than four feet to nearly eight feet.)
  2. 10 percent flood: with a 10 percent chance of being equaled or exceeded in nearly every year, often referred to as the 10-year storm. (Water level increases from nearly eight feet to almost ten feet.)
  3. 2 percent flood: with a 2 percent chance of being equaled or exceeded in nearly every year, often referred to as the 50-year storm. (Water level increases from almost ten feet to more than twelve feet.)
  4. 1 percent flood: with a 1 percent chance of being equaled or exceeded in nearly every year, often referred to as the 100-year storm. (Water level increases from more than twelve feet to nearly sixteen feet.)
  5. 0.2 percent flood: with a 0.2 percent chance of being equaled or exceeded in nearly every year, often referred to as the 500-year storm. (Water level increases from more than fourteen feet to almost eighteen feet.)

Relative Sea Change: 2018

Shows 2018 levels

Relative Sea Change: 2038

Shows 2038 levels

Relative Sea Change: 2058

Shows 2058 levels

Relative Sea Change: 2078

Shows 2078 levels

Relative Sea Change: 2098

Shows 2098 levels

Relative Sea Change: 2118

Shows 2118 levels

Annual Exceedence Probability: 99% Flood

99% probability of flood

99 percent flood: with a 99 percent chance of being equaled or exceeded in nearly every year.

Often referred to as the annual storm. (Water level increases from less than four feet to nearly eight feet.)

Annual Exceedence Probability: 10% Flood

10% probability of flood

10 percent flood: with a 10 percent chance of being equaled or exceeded in nearly every year.

Often referred to as the 10-year storm. (Water level increases from nearly eight feet to almost ten feet.)

Annual Exceedence Probability: 2% Flood

2% probability of flood

2 percent flood: with a 2 percent chance of being equaled or exceeded in nearly every year.

Often referred to as the 50-year storm. (Water level increases from almost ten feet to more than twelve feet.)

Annual Exceedence Probability: 1% Flood

1% probability of flood

1 percent flood: with a 1 percent chance of being equaled or exceeded in nearly every year.

Often referred to as the 100-year storm. (Water level increases from more than twelve feet to nearly sixteen feet.)

Annual Exceedence Probability: 0.2% Flood

0.2% probability of flood

0.2 percent flood: with a 0.2 percent chance of being equaled or exceeded in nearly every year.

Often referred to as the 500-year storm. (Water level increases from more than fourteen feet to almost eighteen feet.)