![\"The](\"https:\/\/www.bates.edu\/magazine\/files\/2012\/02\/popham-091203Popham-Beach_SEr_DICKSON-032.jpg\")
<\/a>The roiling sea in December 2009 threatens the picnic area at Popham Beach. Photography by Stephen Dickson.<\/p><\/div>\n
If Popham Beach is this story\u2019s protagonist, then the antagonist is the Morse River, which exits the coast just west of Popham Beach. In recent years, the river has migrated eastward, cutting away at Popham\u2019s beach, particularly the western part of the beach, though the center beach, which connects to Fox Island, has also been eroded significantly.<\/p>\n
\u201cWe\u2019ve been watching this river shift its course gradually for a long time,\u201d says Bates geology professor Mike Retelle. By 2005, he says, \u201cwe started noticing massive changes\u201d to the Morse River and Popham Beach.<\/p>\n
Two factors pushed the river toward the beach. \u201cA double whammy,\u201d Retelle says.<\/p>\n
One was the relentless growth of a sand spit just offshore from the Morse River outlet. The spit was created by a wave and sand mechanism called longshore sand transport, in which sand-carrying waves hit the shore at an angle and gradually deposit their sediments. Retelle and Dana Oster \u201909 dubbed the Morse River spit \u201cI-95\u201d for its great length and width, and it became an \u201cinsurmountable barrier\u201d that blocked the Morse from flowing directly into the ocean.<\/p>\n
<\/a>This aerial photograph of Popham Beach on March 10, 2010, shows key elements of erosion: (1) the new channel cut by the Morse River last winter, which should save the beach; (2) the old channel that for years had eroded the west side of Popham; (3) the tombolo that makes it possible to walk to rocky Fox Island at low tide. Photograph by John Picher.<\/p><\/div>\n
The sand spit deflected the river toward the beach, and the erosion just got worse and worse. \u201cIt was like a firehose,\u201d Retelle says. As kayakers and canoeists know, when a river curves, the fastest and most powerful flow is the outside of the curve. As the Morse curved into Popham Beach, the strongest part of the current was eating away at the beach.<\/p>\n
\u201cYou want to see natural processes play out,\u201d Retelle says.<\/p>\n
River outlets are always \u201cthe most dynamic places\u201d along the coast, says Retelle. Even so, the stunning changes at Popham had observers \u201cin a panic\u201d by this past winter, Retelle says. Erosion had carved deeply into the dunes and toppled hundreds of shoreline pine trees. The ocean was within feet of the parking lot, and it threatened the park\u2019s new bathhouses. State geologists say it\u2019s the beach\u2019s greatest retreat in a century.<\/p>\n
In its inexorable eastward march, the river had even cut through the sand bar, known as a tombolo, making it nearly impossible for visitors to walk from Popham to Fox Island.<\/p>\n
This past February, some local residents urged that a channel be cut through the sand spit to allow the river to return to a north-south orientation. But others said that the river, and nature, should take its course.<\/p>\n