State of Maine's Beaches in 2007

Ogunquit Beach, Ogunquit

Background geology and characteristics

Figure 143	Ogunquit Beach, located just south and contiguous with Moody Beach, extends southwards from the boundary with Moody Beach for approximately 2.2 km and terminates at the Ogunquit River as a barrier spit that abuts a bedrock headland. The Ogunquit spit most likely formed with transgression of the sea over a low-lying coastal plain of glacial outwash (Heinze, 2001). The spit is prograding into the inlet as a result of a net southerly longshore transport of sand. Once sand reaches the inlet, it circulates in a counterclockwise gyre, and is deposited both in the ebb and flood-tidal deltas.
	Dunes along this beach are primarily artificial and were built in 1974 and 1975 by the Department of Agriculture's Soil Conservation Service (Dickson, 2005). The dunes are cored with gravel and sand imported from an upland source. The top elevation of the dune exceeds the floodplain height and the seaward slope of the dunes is unnaturally steep. Behind the dunes is an extensive back barrier salt marsh system. Erosion has removed part of the frontal dune in the last decade, although there are periods of dune accretion as a result of a relatively successful dune management plan by the Town of Ogunquit. Nelson (1979) found no significant erosional or accretional trend, although the data are strongly influenced by the dike construction in the 1970s. More recent analysis by MGS shows that the dune is relatively stable though the seaward edge may recede rapidly 3 to 6 meters (10 to 20 feet) in response to large storm events (such as the series of northeasters the week of Memorial Day 2005 or the Patriots' Day Storm in 2007). All of Ogunquit Beach is part of the Coastal Barrier Resources System (Dickson, 2006a).
	Ogunquit Beach has 4 measured beach profiles, OG1-OG4. The overall beach is shown in Figure 143. The starting marks have not yet been surveyed by MGS.

Annual and seasonal beach profile changes

The beach profiles along Ogunquit Beach all start within or behind the frontal dune crest. Data at OG1 were available between 2001 and 2006. From 2001-2002, the profile underwent accretion, especially from the berm seaward (Figure 144). Erosion occurred in 2003, removing sediment from the upper portion of the profile, while areas of the profile below about -4 m below the pin (at the 120 m mark) accreted. 2004 data indicate that the profile continued to erode along its entire length, most notably in the offshore area where storage occurred in 2003. Profile lowering and erosion continued in 2005 and 2006, with 2005 being the most erosive. Between 2001 and 2006, the profile lost up to 0.5 m of sediment vertically along its length. Seasonal data at OG1 (Figure 145) show that the beach profile undergoes typical seasonal changes, with accretion in the berm and upper portions of the profile (out to 130 m from the mark) during the summer, and erosion and offshore sediment storage in the winter. The maximum envelope for the summer profile reaches a much higher elevation than the winter one. Standard deviation data (Figure 146a) show large summer berm variation, between 40 and 60 cm, over a large portion of the profile (out to 130 m). The variable berm crest appears to be located at about 40-50 m from the mark. Winter variability appears to be 30 cm or less.

Data at OG2 were available for 2001-2007. The beach at OG2 underwent similar changes as OG1, with substantial accretion between 2001-2002, recession in 2003 (back to near 2001 conditions, Figure 147). The 2004 mean profile shows little change from 2003, with some accretion in the offshore portion of the profile. Slight erosion along the profile occurred in 2005, with fairly dramatic erosion into 2006. 2007 saw slight berm growth and recovery, but loss of sand in the offshore. Seasonal data (Figure 148) indicate little difference between the summer and winter profile shapes, with a slightly better developed berm during the summer. The standard deviation data (Figure 146b) show that the berm and beach for both summer and winter are quite variable, with winter changes on the order of up to 60 cm vertically, and 40-50 cm vertically during the summer.

Similar to OG1 and OG2, the profile at OG3 underwent accretion from 2001-2002, followed by erosion to near 2001 conditions in 2003 (Figure 149). Additional erosion occurred in 2004, with substantial berm loss in 2005 and 2006. 2007 saw slight berm recovery, though the dune appears to have been eroded and the profile lowered in the offshore. Seasonal data show typical winter vs. summer profile shapes (Figure 150), with an inflection point at 110 m offshore. The calculated standard deviation data show summer berm variability up to about 40 cm, concentrated at about the 60 m mark (Figure 146c). Winter data show variability of 30 cm or less.

Unlike the others, OG4 demonstrated very similar profiles between 2001-2002, with only slight accretion at the berm at the 40 m mark in 2002 (Figure 151). No data were available from 2003. In 2004, the profile eroded at the berm and upper portions, but stayed the same farther offshore. 2005 saw additional berm lowering and the entire profile's elevation lowered. The dune and berm continued to recede in 2006. In 2007, the dune lowered further, though a small berm developed at about 20 m from the pin. Erosion continued farther offshore on the profile. Seasonal data (Figure 152) show a slightly more prominent summer berm, with more sediment offshore in the winter. The highest variability was in the berm, which fluctuated during the summer up to 60 cm, at about the 40-50 m mark. Winter variability was about 20 cm along the entire profile (Figure 146d).

The beach profiles at Ogunquit indicate that the beach is undergoing erosion during the time period that data were collected. Significant erosion seems to accompany larger storm events, like the May 2005 northeasters and the Patriots' Day Storm of 2007. Profiles also appear to undergo expected seasonal changes - with summer berm development (albeit highly variable), and winter offshore sediment storage.

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Last updated on January 3, 2008