• Merrymeeting Bay receives the combined flow of the Kennebec and Androscoggin watersheds, the 2nd and 3rd largest watersheds in Maine with areas of 15,200 km2 and 8,900 km 2, respectively.
• The Merrymeeting Bay watershed is equivalent to about a quarter of the are of Maine.
• The combined average annual freshwater discharge into Merrymeeting Bay is about 15,000 cubic feet per second (~9000 cfs for the Kennebec at North Sidney, ~6000 cfs for the Androscoggin at Auburn). This discharge represents the largest single freshwater outflow to the Gulf of Maine during most years (annual discharge through the Penobscot River averages about 14,000 cfs, but some years is slightly higher than the combined Kennebec-Androscoggin flow).
Most years, there is a distinct seasonality to the annual hydrograph , with high flow in late winter/spring related to snowmelt and spring rains, low flow during the dry summers and sub-freezing winter, and variable flow related to wet and dry periods during autumn