Paper No. 6
Presentation Time: 9:20 AM

COASTAL LAND LOSS AND PROPOSED INTERACTIONS IN SACO BAY, SOUTHWEST MAINE, USA


POLLOCK, S.G., Dept. of Geosciences, University of Southern Maine, Gorham, ME 04038, pollock@usm.maine.edu

Camp Ellis, a largely summer community located towards the southern end of Saco Bay, has suffered significant property and coastal land loss for several decades, and has been the subject of numerous studies by various state and federal agencies. Currently, the U.S. Army Corps of Engineers accepts that the erosion is largely caused by a 6600 foot jetty at the mouth of the Saco River. The U.S. Army Corps of Engineers and others have accepted the theory that the jetty blocks the replenishment of sand to the beach system at Camp Ellis from the Saco River, and they also recognize that the normal sediment drift is from the south to the north, away from Camp Ellis.

The last major loss of homes occurred during a March 2007 storm. The total loss of homes over several decades is placed at 30, along with loss of roadways and public and private infrastructure. Mitigation efforts following the 2007 storm included reconstruction of houses, the installation of a sand filled geotube and limited beach replenishment.

An April 2013 mitigation plan by the U.S. Army Corps of Engineers recommends the construction of a 750 foot long spur jetty perpendicular to the existing jetty. Jetty construction, which recent media reports suggest will not begin until 2016, would be accompanied by beach nourishment for approximately 3250 feet north of the jetty and would initially involve 365,000 cubic yards of sand. Estimates call for continuing nourishment approximately once every 12 years. The current plan also calls for cost sharing by the City of Saco, which is unresolved at this time.

The trailing edge of Hurricane Sandy began the 2012 - 2013 winter storm season. While no homes were lost during the 2012 – 2013 winter, storms breached the previously installed geotube and caused extreme beach erosion. As a result of these storms, frontal dunes were significantly impacted, and in some locations frontal dunes effectively no longer exist for a distance up to approximately 7000 feet north of the jetty. Landward beach loss was estimated between 20 and 30 feet in some locations during the 2012 - 2013 winter. Current estimates for the interval between beach nourishment projects, the linear distance requiring nourishment and the volume of future nourishment projects may prove to be too conservative.