Current Water Level

Last update: 2017-08-15 02:46:34

What defines our water level?

Little Sebago Lake, as well as Big Sebago, have historically used the measurement “feet above mean low tide Portland harbor” to state our water level. The standard dates back to the days when S.D. Warren owned the lake and used a series of dams to control the flow of ice and logs to the Presumpscot, and out to the harbor.

The “Warren Standard”, for lack of a better name, was cited in the 1984 DEP agreement with the Little Sebago Lake Association as the measurement standard for maintaining the summer and winter level of Little Sebago Lake. The agreement document states that Little Sebago Lake will be maintained at 289.2 feet above mean low tide Portland harbor from April 15 through October 15, and lowered for the winter October 15 thru April 15th to a winter level of 18" to 21" lower. We hit -18" about a third of the time but a Winter level of -15" is the norm. The lake will drop 8" to 12" by Thanksgiving and 12" to 15" by New Years. The basic idea behind lowering the lake is keep the frozen lake from damaging the shoreline with an added benefit of increasing flush rate. It also helps to minimize flooding concerns in the spring when experiencing excess snow melt combined with heavy rains.

The Warren Standard is not the same measurement used by the US Geological Society. That measurement uses as its basis “feet above sea level”. The two standards have a difference of 3.48 feet.

The Collins Pond Dam is the first working dam downstream from Little Sebago Lake. This photo was taken during the 2012 spring flood when Little Sebago Lake was 15" above summer level. Please note the water going over the top of the dam, this is why we need to be careful when releasing water from Little Sebago.