The New Hampshire Department of Environmental Services (NHDES) is leading the New Hampshire King Tides initiative to document the effect that extreme tide events have on our state’s beaches, coastal waterways, private property, and public infrastructure.

The term “King Tide” is a non-scientific term used to describe the highest seasonal tides that occur each year. These tides occur naturally and are typically caused when a spring tide (when the sun, moon, and earth align during a new and full moon, increasing tide ranges) takes place when the moon is closest to Earth during the 28-day elliptical orbit (known as a perigee).

The effect of individual King Tides may vary considerably. In some cases, they may barely even be noticed. In other cases, a King Tide may cause coastal erosion, flooding of low-lying areas and disruption to normal daily routines. This is particularly true when a King Tide event coincides with significant precipitation because water drainage and runoff is impeded. Over time, the frequency and effect of King Tide events may increase due to gradual mean sea level rise.

NHDES Needs Your Help

NHDES needs your help to capture photographs of King Tide events. DEEP will evaluate your photographs and include them in its long-term analysis of coastal vulnerability and planning initiatives with municipalities. NHDES may also use your photographs in presentations, publications, and on its website.

Tips for Effective King Tides Photos

  • Take pictures at or near peak high tide.
  • Take pictures where the impact of the tide can be gauged against familiar landmarks like buildings, roads, sidewalks, parking lots, jetties, bridges, sea walls, shorelines, or bulkheads.
  • Taking contrasting shots of peak high and peak low tides helps to show the tidal variability.
  • Be Safe! Use good judgment when you are taking your photos. Stay away from dangerous situations particularly in stormy conditions and avoid taking risks.