State of Maine's Beaches in 2007

Goose Rocks Beach, Kennebunkport

Background geology and characteristics

Goose Rocks Beach is an approximately 3 km long sandy pocket beach that stretches southwest-northeast and is bound by two tidal inlets, the Little River to the northeast and the Batson River to the southwest. The shoreline along the beach is quite arcuate, mainly due to wave refraction around offshore islands and shoals. Dynamic beach spits are located at both ends of the beach, adjacent to the tidal inlets. Southwest of the sand beach is a headland with mixed sand and gravel beaches on Nessler and Marshall Points. According to Nelson (1979), the historical limit of erosion is landward of many homes within the dune system. Approximately 60% of the shoreline along Goose Rocks Beach is armored (Beach Stakeholder Group, 2006). There are no new significant sources of sand to replace sediment transported into the tidal inlets or eroded from the beach and carried to offshore sand bars (Dickson, 2006a).

Goose Rocks has 4 measured beach profiles, GR1-GR4. The overall beach is shown in Figure 89. The starting points have not yet been surveyed by MGS.

Annual and seasonal beach profile changes

Beach profiles at Goose Rocks Beach start behind the dune crest and also within seawalls. Profiles at Goose Rocks Beach tend to be very flat and long (out to about 500 m from the pin) and variable, mostly due to the sheltered area and influence of offshore islands and shoals. Continuous data were collected from 2002 through 2007. The beach at GR1 is adjacent to the Batson River ebb-tidal delta, and reflects this variability in the profile shapes (Figure 90). There is no contiguous pattern of either erosion or accretion, with changes being highly variable. There was general accretion along the profile from 2002-2003, with continued buildup of sediment adjacent to the seawall and berm into 2004, though some volume of sediment was lost on the middle portion (between 100 and 240 m from the pin). From 2004 to 2005 there was sediment loss along the entire profile. The beach fronting the dune/wall continued to recede into 2006, though more sediment appeared in the central portion of the profile. By 2007, the beach fronting the seawall stabilized, and additional accretion took place in the central portion of the profile. Seasonal mean data (Figure 91) show that there is generally little change from winter-summer, though the winter profile shows slightly more sediment nearer to the seawall. Profile envelope variability indicates that both seasons are somewhat variable, with values between the minimum and maximum envelopes on the order of 1 m. Standard deviation data (Figure 92a) show that the berm has more variability (55 cm) in the winter than the summer (45 cm). The berm's position appears to stay the same, around 20-35 m from the pin.

GR2 is much shorter in length than GR1. It appears that the profiles at GR2 collected in 2002-2003 may have started from a different location than the remaining years (Figure 93). If not, then the beach underwent accretion from 2002-2004. A berm, present in the 2002 profile at the 25 m from the pin mark (at an elevation of 1.5 m below the pin), was eroded by 2003. Data from 2003-2007 indicate that the beach changed little over this period of time and is relatively stable. On a seasonal basis (Figure 94), GR2 displays the typical sediment-rich summer berm, with sediment loss in the nearshore and growth of a sandbar farther offshore in the winter. Based on the mean seasonal shapes, berm fluctuation appears to be about the same for summer and winter. This is confirmed by standard deviation data (Figure 92b), which show changes on the order of about 40 cm for both seasons. The position of the berm appears to remain about the same.

The beach at GR3 appears to have been relatively stable between 2002-2004, then underwent a period of erosion in 2005 (this being the most erosive profile of the data, Figure 95). In 2006, the berm appears to have recovered, and this trend continued into 2007. Like GR2, GR3 shows a seasonal bias (Figure 96), with more sediment in the berm area during the summer, and more sediment in the bar area during winter. Profile envelope variability appears to be about the same for winter and summer, though the summer berm appears to reach a slightly higher elevation. Standard deviation values (Figure 92c) for the berm are greater in the summer profile. It seems the greater vertical variability is located farther from the mark at GR3 (around 40-50 m from the pin) than GR2 (25-30 m).

Profiles collected at GR4 are located near the Little River, and thus, are longer like the profiles from GR1. From 2002-2004, there was erosion of the berm area, with some growth offshore (Figure 97). From 2004-2005, the berm began recovery while the offshore portion of the profile remained stable. 2006-2007 saw continued berm growth, with little changes in the offshore. Seasonally, the summer profile (Figure 98) exhibits more sediment adjacent to the dune and berm than the winter profile. Standard deviation data (Figure 92d) indicate that the berm fluctuates vertically almost 70 cm in the summer, and 60 cm in the winter. Variability is greater than 40 cm along the majority of the profile, and increases to nearly 80 cm offshore, likely attributable to sandbar migration adjacent to the Little River.

Profiles along Goose Rocks Beach are influenced by the bounding rivers, and offshore, wave-sheltering outcrops and islands. The beach has been variable - with loss, especially in 2005, though it appears that the beach has the ability to recover from such loss. Seasonal variability is typical.

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Last updated on January 3, 2008