Seattle Public Utilities Mami Hara, General Manager/CEO

Sea-Level Rise Map

Projections

11’NAVD88

  • 2 feet above MHHW
  • MHHW most likely by 2076; possibly as soon as 2056
  • Monthly high most likely by 2049; possibly soon as 2033
  • Annual extreme tide today

12’NAVD88

  • 3 feet above MHHW
  • MHHW most likely by 2099; possibly as soon as 2074
  • Monthly high most likely by 2076; possibly as soon as 2056
  • Annual extreme tide by 2049; possibly as soon as 2033

13’NAVD88

  • 4 feet above MHHW
  • MHHW most likely by 2116; possibly as soon as 2090
  • Monthly high by 2099; possibly as soon as 2074
  • Annual extreme tide most likely by 2076, possibly as soon as 2056

14’NAVD88

  • 5 feet above MHHW
  • MHHW most likely by 2131; possibly as soon as 2104
  • Monthly high most likely by 2116; possibly as soon as 2090
  • Annual extreme tide most likely by 2099; possibly as soon as 2074

Note: Probabilities have not been assigned to SLR estimates; however for the purposes of communicating time of emergence, “most likely by” refers to NRC 2012 projected mean, and “possibly as soon as” refers to NRC 2012 high range.

Map Notes

The projections and scenarios are based on a 2012 National Research Council report (“Sea-Level rise for the Coasts of California, Oregon, and Washington: Past Present and Future”). Water levels account for the National Tidal Datum Epoch 1983-2001 (NTDE 83-01). The base digital elevation model (DEM) used in the analysis was produced using data from the 2016 regional lidar project by King County & the Puget Sound LiDAR Consortium. The non-vegetated vertical accuracy for the project is calculated at 0.172 feet (0.052 meters).

Sea-Level Rise ("SLR") information is prepared for use by The City of Seattle for its internal purposes only, and is not designed or intended for use by members of the public. ALL SUCH SLR INFORMATION AND CONTENT IS PROVIDED ON AN "AS IS", "AS AVAILABLE" BASIS WITHOUT WARRANTIES OF ANY KIND EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, ACCURACY, AND NON-INFRINGEMENT. The City of Seattle makes no representations or warranty as to its accuracy, and in particular, its accuracy as to labeling, completeness, reliability, currency, dimensions, contours, property boundaries or placement of location of any map feature thereon. In no event will The City of Seattle be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from loss of data or profits arising out of, or in connection with, the use of any SLR information.