Post-Hurricane Sandy: Old Inlet Breach on Fire Island

Monitoring the Breach

Charts & Graphics

Results to Date

 

View of Old Inlet on Fire Island, as seen from a 2010 overflight. Note the boardwalk trail across a narrow portion of the Fire Island Wilderness, ending in a T-shaped dock across from Pelican Island.

 

View of Old Inlet on Fire Island as seen on November 4, 2012, after the arrival of Hurricane Sandy on October 29, 2012. Note the breach (where water is exchanged freely between the Atlantic Ocean and Great South Bay)  at the location of the Old Inlet boardwalk, leaving the Old Inlet dock standing and no longer connected to the island. This view also shows some of the overwash fans that were formed by the movement of sand across the island during the storm.

 

You can see the breach at Old Inlet by walking west 1½ miles from the Wilderness Visitor Center.  Strong currents in the breach are hazardous, therefore boating of any kind, swimming, and wading in the breach is not allowed.

Fire Island Breaches

The force of the wind and storm surge caused by Hurricane Sandy on Monday, October 29, 2012, caused numerous overwashes and resulted in three breaches (where water freely flows between the ocean and the bay) on barrier islands along the south shore of Long Island. Two of those three breaches were on Fire Island and within the boundaries of Fire Island National Seashore: one at Old Inlet (within the Otis Pike Fire Island High Dune Wilderness) and another in Smith Point County Park.

Within 48 hours of the storm the Breach Contingency Plan (BCP), put in place in 1997 to address any breaches that impact coastal Long Island from Fire Island Inlet east to Montauk Point, was implemented by a multi-agency group including the National Park Service (NPS), U.S. Army Corps of Engineers (USACE), and New York State Department of Environmental Conservation.

The BCP calls for filling breaches which do not occur in the federally designated wilderness area. For the breach at Smith Point County Park, which is within Fire Island National Seashore boundaries but is not within the wilderness area, BCP actions were implemented immediately to close the breach by mechanical means. Closure was completed in November 2012.

For a breach within Fire Island National Seashore's wilderness area, the BCP calls for the NPS to monitor and evaluate the breach for a period of 45 to 60 days to determine if the breach will close naturally. That initial monitoring period passed at the end of December 2012. Since the breach was relatively stable, the BCP team decided to continue monitoring at that time.

Between January and mid-March 2013, when a series of winter storms affected the island, the new inlet migrated to the west and its channel deepened. BCP partners began preliminary steps to prepare for the implementation of a closure of the breach. (See March 27, 2013 update.)

Currently, monitoring data indicates that the breach is dynamic but there is a likelihood that closure by natural processes may occur in the future. Based on this evaluation, the NPS is continuing to monitor the wilderness breach.

 

Aerial view of the breach at Old Inlet, 1½ miles west of the Wilderness Visitor Center, as seen from the Atlantic Ocean to the bay on November 2, 2012.

NPS Photo/Dunphy

 

Monitoring the Wilderness Breach at Old Inlet

While storm events and breaches are part of a barrier island's natural processes and breaches can provide ecological benefits, decisions about the breach must be balanced by concerns that the breach may exacerbate flooding in adjacent communities of Long Island's south shore. Monitoring of the breach at Old Inlet began within 48 hours of Hurricane Sandy. The State University of New York at Stony Brook, U. S. Geological Survey (USGS), National Park Service (NPS), USACE, and other coastal experts have been regularly monitoring the wilderness breach conditions (breach position, depth, and tidal exchange), and water levels and water quality in Great South Bay.

Breach Shoreline Position

The location of the breach has been monitored at least weekly since the breach opened to determine if the breach is migrating or widening. Mapping-grade GPS shoreline position data is collected by walking the east and west boundaries of the breach within 2 hours of ocean low tide. Paired measurement of the east and west breach boundaries (generally collected on consecutive dates) identify the location as well as the width of the breach.

During the first 60 days after Sandy, NPS staff evaluated the position of the breach on an almost daily basis. Monitoring has continued on at least a weekly basis. Shoreline position data from selected dates is presented in the table (below).

Old Inlet Breach: Shoreline Position
NPS Measurements (west side/east side)		Breach Length	Width at North End (bay side)	Width at South End (ocean side)
November 3-6, 2012		908 ft (277 m)	276 ft (84 m)	108 ft (33 m)
November 7-8, 2012		853 ft (260 m)	236 ft (72 m)	144 ft (44 m)
November 19-20, 2012		899 ft (274 m)	328 ft (100 m)	170 ft (52 m)
November 26-27, 2012		945 ft (288 m)	328 ft (100 m)	623 ft (190 m)
December 3-6, 2012		984 ft (300 m)	328 ft (100 m)	347 ft (106 m)
December 9-10, 2012		810 ft (247 m)	328 ft (100 m)	334 ft (102 m)
December 12-13, 2012		1030 ft (314 m)	328 ft (100 m)	427 ft (130 m)
December 17-20, 2012		716 ft (218 m)	331 ft (101 m)	564 ft (172 m)
January 4-3, 2013		721 ft (220 m)	272 ft (83 m)	521 ft (159 m)
January 10-12, 2013		859 ft (262 m)	436 ft (133 m)	475 ft (145 m)
January 17-15 and 24-23, 2013 breach shoreline positions
February 13-14, 2013		702 ft (214 m)	607 ft (185 m)	827 ft (252 m)
February 21-20, 2013		682 ft (208 m)	623 ft (190 m)	613 ft (187 m)
February 26-28, 2013		682 ft (208 m)	616 ft (188 m)	1171 ft (357 m)a
February 7 - March 5, 2013 breach shoreline positions
March 13-11, 2013		702 ft (214 m)	696 ft (212 m)	732 ft (223 m)
March 21-22, 2013		705 ft (215 m)	856 ft (261 m)	745 ft (227 m)
March 5 - April 4, 2013 breach shoreline positions
April 11-10, 2013		728 ft (222 m)	656 ft (200 m)	991 ft (302 m)
April 24-23, 2013		728 ft (222 m)	620 ft (189 m)	974 ft (297 m)
April 10 - April 24, 2013 breach shoreline positions

^a High water levels and wide runnel prevented field crew from safely walking breach shoreline on south (ocean) end on this date

Breach Depth and Tidal Exchange

Physical surveys have been conducted in the breach to determine the depth and cross-sectional area of the breach as well as tidal exchange through the breach.

U. S. Geological Survey (USGS) Water Resources Division staff conducted a physical survey of the Old Inlet breach on November 6, 2012, and a follow-up survey on November 20, 2012.

• Evaluation of a barrier-island breach created by Hurricane Sandy at Fire Island National Seashore, NY (USGS)

Stony Brook University's School of Marine and Atmospheric Sciences has also completed physical surveys of the breach on December 7 and 20, 2012, and February 3 and 22, 2013.

Water Levels and Water Quality in the Great South Bay

Stony Brook University's School of Atmospheric Sciences (SoMas) has been collecting water level, salinity and water temperature data throughout the Great South Bay as part of its Great South Bay Project. This monitoring network includes a station at Bellport, New York, approximately 2.7 miles northwest of the Old Inlet breach. The Bellport station, which was established in 2004, is being used to evaluate the effects of the breach at Old Inlet. Monitoring so far shows that since Hurricane Sandy, tide levels recorded at Bellport have returned to pre-Sandy conditions.

• Stony Brook University School of Marine and Atmospheric Sciences Helps the Region Understand and Learn from Superstorm Sandy (SoMAS)
• SoMAS Superstorm Sandy 2012 Reports
• SoMAS Great South Bay (Buoy #1)
• The Impact on the Great South Bay of the Breach at Old Inlet (SoMAS/Flagg, March 15, 2013)

 

Aerial view of the breach at Old Inlet, looking from the Atlantic Ocean to the bay, on Saturday, November 10, 2012.

NPS Photo/Abell

 

View across the west side of the breach at Old Inlet from its northern shoreline. The small house is a Pattersquash Gun Club building on Pelican Island, across from the dock at Old Inlet.

NPS Photo on 1-4-2013

 

National Park Service staff continue to monitor the breach at Old Inlet, measuring its shoreline at low tide.

NPS Photo on 1-4-2013

 

Old Inlet Breach - Shoreline Position Graphics

 

NOAA aerial photo taken on Nov. 4, 2012 shows location of the breach on Fire Island one week after Hurricane Sandy's arrival. National Park Service measurements of breach shoreline position are shown in overlays. Shoreline position data is collected within 2 hours of ocean low tide by walking the breach shoreline with mapping-grade GPS equipment on consecutive days. Paired shoreline position data is used to calculate breach width and determine if the breach has migrated.

 

Following the November 7-8, 2012 nor'easter, the breach channel shifted west and extensive shoaling occurred north of the breach. For about a week after that nor'easter, Fire Island and Pelican Island were connected.

 

The breach at Old Inlet moved west following storms in December 2012.

 

 

NOAA photo/NPS-data

 

 

 

 

Monitoring Results for the Old Inlet Breach

To date, breach monitoring data indicates that:

1. The breach, although not static, is relatively stable and there is a likelihood that closure by natural processes may occur in the future.
2. Water levels and tidal amplitude in eastern Great South Bay returned to normal soon after Hurricane Sandy and have remained in the normal range.
3. Water exchange between the ocean and bay has increased in eastern Great South Bay.
4. Extensive shoaling has occurred within the Great South Bay just north of the breach.

The National Park Service will continue to work with its partners to monitor the breach, ensuring that data is available to inform management decisions.

 

Additional information and updates will be provided when available.

• Facebook/FireIslandNPS
• Twitter.com/FireIslandNPS
• NPS Superstorm Sandy Response on Facebook
• SandyResponseNPS on Twitter
  Hurricane Sandy impacted three National Park Service regions and nearly 70 parks. Follow updates as each comes back on line.
• USGS: Hurricane Sandy

 

Additional Information about the Breach Contingency Plan and Breach Management

The National Park Service is one of several agencies involved in an interagency breach management response for the south shore of Long Island, as part of the U. S. Army Corps of Engineers Fire Island to Montauk Point Reformulation Study. After Hurricane Sandy's arrival, the 1997 Breach Contingency Plan for Fire Island was implemented.

• Fire Island National Seashore Finding of No Significant Impact (FONSI), April 9, 1996 for the Draft Fire Island to Montauk Point, Long Island, New York, Breach Contingency Plan (U. S. Army Corps of Engineers) 582 pages
  August 1995, Revised January 1996

• Recommendations for a Barrier Island Breach Management Plan for Fire Island National Seashore, including the Otis Pike High Dune Wilderness Area, Long Island, New York
  Technical Report NPS/NER/NRTR-2007/075
  Abstract
  by S. J. Williams and M. K. Foley
  National Park Service
  February 2007

 

Fire Island National Seashore's enabling legislation (Public Law 88-587, September 11, 1964) allows for shore erosion control or beach protection measures within park boundaries, under certain criteria. (See Sec 8)

The Otis Pike Fire Island High Dune Wilderness Act (Public Law 96-585, December 23, 1980) designated approximately 1,363 acres as wilderness in Fire Island National Seashore. This wilderness designation does not preclude the repair of breaches that occur in the wilderness, under specific circumstances. See (d)

A 1983 Wilderness Management Plan (WMP) for Fire Island National Seashore also addresses breaches in the wilderness area. (See page 18 of the WMP.)