Storm Effects on Dauphin Island
Tropical hurricanes and winter storms have devastated the island over
time. Historic data indicate that 2005 was the most active year of
record for the Atlantic Basin. A total of 28 named storms occurred in
that year, with five making landfall along the northern Gulf Coast.
Of these Katrina and Rita were the most noteworthy since they were
classified as Category 5 storms during a part of their life and were
extremely powerful events when they struck the coast, affecting
extensive coastline areas well to the east of the actual landfall point.
Hurricane Katrina resulted in the loss of an average of 2.3 feet in elevation on the
south beach at Dauphin Island’s west end, with the island shifting
between 87 to 492 feet to the north during this single catastrophic
Tide Lines with Lot Line Overlays
Pre-Isadore (2002) & Post-Katrina (2006)
(click photo to enlarge)
Other storms which have exacted severe damage to the island:
Hurricane Frederick (Category 3) caused major damage
to the island in September 1979, being the “signature” storm event
for many years.
Hurricane Elena (weak Category 3) came close enough
to the island to have a significant impact in August 1985.
The decade between 2000 and 2010 saw a large number
of tropical systems impact Dauphin Island. Hurricane Ivan (Category
3) and Hurricane Katrina (Category 3) in September 2004 and August
2005, respectively, are the most recent hurricanes to have severely
altered the shoreline configuration of and elevations on Dauphin
Tropical Storm Isidore in September 2002 destroyed
the FEMA berm along the island’s western south shore.
Although Hurricane Ike (strong Category 2) made
landfall in Galveston, Texas, in September 2008, the immense size of
that storm generated considerable wave action at Dauphin Island that
aggravated coastal erosion problems.
Each year since Hurricane Katrina, small but more frequently occurring
storm events are having increasingly adverse effects on the morphology
of Dauphin Island. The heightened tropical storm activity between 2000
and 2010 has lowered the elevation of the West End of Dauphin Island and
greatly eroded the shoreline.
As a result, small storm events that would previously not have had much
effect on Dauphin Island are now causing significant overwash events
that carry increasing quantities of sand to the northern shoreline. The
frequency of these events hinders the establishment of vegetation
necessary to hold the sand, which allows further losses due to wind
between storm events.
(click photo to enlarge)
The effects of the smaller storms began to be especially apparent during
the winter and spring of 2008-2009 and are continuing to impact Dauphin
Island beginning in November 2009. The only tropical system to affect
Dauphin Island made landfall on November 9. Ida barely met the wind
strength as a weak Category 1 hurricane and was downgraded to a tropical
storm before it made landfall. But while Ida only produced maximum
sustained winds of 45 mph, the extremely weakened state of the western
end of Dauphin Island made it susceptible to considerable shoreline
erosion. Examination of the hourly wind speeds and maximum gusts created
by this 3-day (November 8-10) storm event on Dauphin Island show that
sustained winds during Ida generally ranged between 20 and 30 mph during
There is no question that naturally-occurring storms effect damage to
Dauphin Island and contribute to erosion.
Yet even with heavy storm activity, the island was able to reestablish
itself in the past. This reestablishment pattern has been all but
lost since the interruption in the natural littoral drift system caused
by maintenance dredging in the Mobile Outer Bar Channel.
More factors contributing to erosion