Friends of Sebago Lake Comments for Portland Water District Board of Trustees Workshop -February 9, 2009
Re: Impacts of Sebago Lake Water Level Regulation
Unlike 25 years ago, today’s scientific information about the impacts of unnatural lake level regulation is readily available. We have learned that unnatural lake regulation brings great harm to biodiversity, to health of lake and riparian biota, and to water quality. We have learned that when the reduction of the natural fluctuation range of lake water levels is reduced and interannual variability is lost, water quality degrades. A clear example of this is China Lake in Maine. In the early 1970’s, the seasonal 4 to 6 foot fluctuation of China Lake which mimicked the natural hydrological cycle was abruptly altered to a highly constant elevated lake level management. Within 5 years, shorelines began to erode and large lake wetlands began to disintegrate. The lake water quality catastrophically collapsed and soon after the term “China Lake Syndrome” was incorrectly coined to define a lake where uncontrolled watershed runoff rapidly destroyed the lake’s water quality. In the mid 1990’s the National Press and TV news generated numerous stories about this unprecedented and alarming phenomena. The significant water level management change was never mentioned. It is well known that uncontrolled watershed runoff can degrade a lake. However, if the natural resilience of the lake has been destroyed by unnatural water flowage, restoring water quality to its former clear state will be difficult if not impossible if the biological and physical mechanisms which protect the water quality are broken .
Sebago lake is the most resilient lake in Maine but the same unnatural regulation impacts responsible for the real “ China Lake Syndrome” are also attacking the resilience of Sebago Lake. Reduced fluctuation prevents wetlands from drying out in the growing season, and reestablishment of seeds banks that maintain biodiversity of plant and animal life. Wetland and lake bottom littoral sediments can not compact , consolidate or oxide nutrients. In the summer, beaches are submerged eliminating a powerful natural filter and diminishing the natural protection from upland erosion pollution. It is not surprising that Sebago Lake water quality is deteriorating. Like China Lake, Sebago’s storage capacity has been reduced to insure full lake levels each spring and thus increasing the chance for a catastrophic flood. Like China Lake, Sebago Lake has an outlet river which can not safely pass large flows due to anthropogenic changes along the river course. This combined with reduced storage capacity in the lake is dangerously irresponsible.
Last summer FOSL contacted Dr. Douglas Wilcox of SUNY-Brockport, because we had questions about the Normandeau 2003 Wetlands Report and impacts of the present water level regulation. Dr. Wilcox is considered by his colleagues to be one of the top lake wetland scientists in the United States. Because he could not answer our questions without actually visiting the study sites he agreed to travel to Sebago Lake last fall for a two day field study. We recently received his Sebago Lake report which we have made available to PWD and the public on the FERC elibrary docket p-2984 for Eel Weir Dam. Dr. Wilcox conclusions are derived from a lifetime of study and writings on the impacts of lake level regulation on northern lakes. His many collaborative studies published with the backing of the United States Geological Service are all peer reviewed by other accomplished lake biologists. FOSL believes that before water quality certification is issued for the relicensings of the Eel Weir Dam, the top lake wetland biologists in this nation should be brought into to study and evaluate the impacts of the present water level regulation on Sebago Lake’s ecosystem and water quality. Present studies for and conclusions of the FERC Environmental Assessment are very inadequate. We invite Portland Water District and all interested parties to become part of FOSL’s efforts to insure that Sebago Lake’s water management is based on the best science so that its water quality, ecosystem and physical environment can be restored and protected.
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President, Friends of Sebago Lake