State of Maine's Beaches in 2011

Introduction

The 2011 State of Maine's Beaches Report provides a follow up from the first report issued in 2007 (Slovinsky and Dickson, 2007), and a second report, issued in 2009 (Slovinsky and Dickson, 2009). The purpose of the report is to summarize major observed morphologic characteristics and changes of Maine beaches that are monitored as part of the State of Maine Beach Profiling Project (SMBPP; Maine Sea Grant Extension, 2003). The SMBPP utilizes trained volunteers to collect monthly beach profiles which start at a known point or benchmark (usually in the frontal dune or in a seawall) and continue shore-perpendicular to roughly the low water line. Fixed starting locations are used with the Emery Method of beach profiling (Emery, 1961). Data collected is entered by volunteers into an online database, where it is accessible for outside researchers (Maine Shore Stewards, 2007). The SMBPP is funded and managed by combined efforts of the Maine Geological Survey, University of Maine, Maine Sea Grant, and Maine Coastal Program.

The previous State of Maine's Beaches report discussed the data collection methodology used by the SMBPP program, and documented the changes that were observed in beach and dune topography at each beach profile on a year-by-year and seasonal (summer vs. winter) basis since the start of data collection (1999 for some beaches) and continuing through April 2006.

This report will build upon the last assessment, which reviewed the changes that occurred since the April Patriots' Day Storm of 2007. This report will document additional changes at beaches since 2009, during the winter and summer months, at each location.

Spatial and Temporal Extent of Data for 2011 Report: Beach Profile Data

Figure 1

The locations of beaches involved in the program as of May 2011 are shown in Figure 1. Note that Western Beach (Scarborough) and Fortunes Rocks Beach (Biddeford) are no longer part of the profiling program. Generally, there are 2-4 profiling locations along each beach. Along each collected profile, topographic (elevation) points are generally collected at approximately 3-meter (10-foot) intervals, from the starting point (usually a stake in the dune crest or mark on a seawall) seaward to the low-water line using the Emery Method of profiling.

This report will compare profile data from immediately post-Patriots' Day Storm (i.e., April or May 2007), and profile data from the subsequent closest months from 2008 through 2011, as available. Late spring is typically when the beach profile shape is lean, with little sand on the upper portion of the beach after a season of winter storms. The immediate, post-Patriots' Day storm beach profile is considered to be the starting point for recovery. Spring beach profiles that were used for this analysis are shown in Table 1. This kind of analysis builds on the work completed for the 2009 beaches report.

The report also analyzes the changes of the "summer" beach shape from 2007 through 2010, in order to investigate whether or not the typical recreational beach - usually defined by a wider, sand-rich beach profile, was able to recover each year. Summer beach shapes are typically fully developed by August or September, after a season of gentle waves and accretion. Summer beach profiles that were used for this analysis are shown in Table 2.

For this analysis, it is important to note that some locations have been discontinued from profiling, including Fortunes Rocks Beach in Biddeford, and Western Beach in Scarborough. Other sites, such as Ogunquit, only have limited data at several profile points. Many beach profile starting points were lost in the Patriots' Day Storm, which led to some post-storm data gaps, or problems in relating profiles taken from front stakes (lost in the storm) to profiles recorded from back-stake starting points.

The 2007 Patriots' Day Storm

The Patriots' Day Storm of 2007, which was detailed in depth the 2009 report, battered the Maine coastline for days with heavy winds and rain, large waves, and a high storm surge, and had a large impact on Maine's beaches. Offshore waves during the storm reached upwards of 8 meters (30 feet), and stayed above 3 meters (9 feet) for several days, while winds were measured at 60 mph in Portland, and gusts approaching 80 mph were reported in Cape Elizabeth.

Tide gauge recordings (NOAA COOPS, 2007; Slovinsky, 2007) of water levels in Portland Harbor indicated that the storm produced a surge (an extra elevation of the sea) driven by the wind and low barometer to levels of 0.7 meters (or 2.5 feet) above that predicted. The storm surge is the difference from the predicted tide and the storm tide as recorded by the tidal gauge. The surge peaked between 10 and 11 a.m. on April 16, 2007 and remained elevated for 6 more high tides before the storm's influence abated. As a result of the high winds, waves, and tides, extensive beach erosion occurred.

The Winter of 2010

The winter of 2010 was punctuated by a series of significant storm events that left many of Maine's beaches in relatively poor shape going into the 2010 summer season. The winter of 2010 started off relatively average, with three storm events with wave heights exceeding 2 m (6 feet) in early, mid, and late January. Winter waves of this height are not out of the ordinary. However, this was due to change.

Most of February was very quiet until the end of the month. Then, a larger northeaster which started on February 24 and lasted several days struck, with wave heights peaking over 6.1 m (20 feet) on February 26 (Figure 2). The storm produced a surge of 1-2 feet which lasted from February 24 to March 1, and peaked with a large storm surge of just over 4 feet on February 26 (Figure 3). The last time a surge of over 4 feet was recorded at the Portland tide gauge was in 1947. This pushed higher than normal "spring" high tides up to or over 12 feet above MLLW (mean lower low water) 5 times between February 26 and March 4.

Figure 2

Figure 3

Figure 4

Then two weeks later, another large multi-day northeast storm hit the coast. Starting on March 14, wave heights grew and peaked to 5.5 m (18 feet) on March 15, and stayed over 2 m (6 feet) until March 17. However, this event was not nearly as potent as the February storm, since it coincided with lower astronomical tides (around 8-9 feet above MLLW). Also, the surge was lower, running generally between 1 to 2 feet from March 13 to 17. Thus, total water levels remained below 11 ft MLLW for the duration of the event (Figure 4).

As a result of this "one-two punch," many southern Maine beaches experienced very high levels of beach erosion. This resulted in some beaches being eroded vertically to levels even lower than the 2007 Patriots' Day Storm event, and exposed old marsh surfaces in the surf zone that had not been seen in decades (e.g., Higgins Beach in Scarborough). This also led to a generally steeper beach face, and a very low low-tide terrace at some beaches. This enhanced rip-current formation during the later summer months, which was reported in the news throughout the summer of 2010. This phenomenon occurred at Old Orchard Beach for much of the summer, and resulted in above average lifeguard rescues.

Contents Introduction Beach Responses Discussion Conclusions References Appendix-Popham

Last updated on July 14, 2011