Hydrology of the Lake Champlain basin

Shanley, J. B. and Denner, J. C. (1999) The Hydrology of the Lake Champlain Basin, in Lake Champlain in Transition: From Research Toward Restoration (eds T. O. Manley and P. L. Manley), American Geophysical Union, Washington, D. C.. doi: 10.1029/WS001p0041

Lake Champlain lies in a broad valley between the Adirondack Mountains of New York and the Green Mountains of Vermont. Lake waters discharge to the north via the Richelieu River to the St. Lawrence River at Sorel, Québec. The lake itself occupies only 5.4% of the 21,150-km²basin. Most of the inlets are high-gradient streams which peak within 24 hours in response to precipitation or snowmelt. In most of the mountainous basin, a high percentage of the winter precipitation is stored in the snowpack. Therefore, the dominant hydrologic event of the year is spring snowmelt, when nearly one-half of the annual streamflow typically occurs in a six to eight-week period. Because of the geometry of the Lake Champlain outlet, lake outflow cannot keep pace with stream inflow during snowmelt. As a result, the peak lake level lags the peak inflow by several days. In all but 3 of the 128 years of record, the peak annual lake level has occurred during spring. Although the highest historical water level of 31.12 m (102.1 ft) occurred in 1869, near-record levels occurred in 1993 and 1998; those events are analyzed in this paper. Alterations to the outlet channel have caused a general rise in the lake level of about 0.15 m (0.5 ft) since the 1960’s.