Trip report for visit to Acadia National Park, September 15 - 16, 2010

Smillie, Gary; Ellsworth, Alan

Field work: September 15-16, 2010. Trip report for visit to Acadia National Park; Sieur de Monts and The Tarn, flooding and filling respectively. This report summarizes a trip to ANP to investigate the flooding occurring in the Great Meadow area and the filling in of the open water area at The Tarn. The Great Meadow area is reportedly flooding due to an undersized culvert that does not have the capacity for handling the volume of water during storm events. The Tarn is experiencing rapid filling with aquatic vegetation due to long term sedimentation build up and reached a point that the depth is adequate for vegetation to become established; however, now that the vegetation is established its presence exacerbates the build up of more sediment. Research and/or Management Recommendations: For the Sieur de Monts/Great Meadow area, it is recommended that an engineering study is needed to quantitatively analyze the factors that cause the flooding. A list of different factors important for the full assessment is provided. For the Tarn: Essentially there are two immediate recommendations for The Tarn. One is to raise the water level in the pond by raising the height of the dam and the other is to remove the sediment. Both are noted to be only short term fixes. An investigation of sediment source is recommended, but sedimentation to a certain extent is a natural process and the only long term management option is regular removal of sediment build up. However, “Given the environmental issues associated with sediment removal and the need for repetitive action, it would seem that maintaining open water in The Tarn should only be considered if the area is managed primarily for a cultural or historic appearance.”