The interaction of lakes and groundwater is controlled in part by the configuration of the water table near a lake. Seepage from lakes does not occur if the water‐table mound between the lake and a regional groundwater discharge area is sufficiently high and the water‐table gradient between the mound and the discharge area sufficiently small. Water‐table configurations associated with two groundwater systems of different geometry were examined by digital simulation. For the first setting, there is no seepage from the lake if the water‐table gradient from the mound to the regional discharge area is ≲0.011; for the second, the critical gradient is about 0.009. Seepage from the lake occurs if water‐table gradients are greater than these two values. For various glacial terrains, in which most natural lakes occur, water‐table gradients of 0.010 or greater are most common in the more rugged end moraines consisting of silty till, and gradients of ≪0.010 are common in areas of ground moraine, outwash plains, and flood plains.