Water gradually escapes by seepage through the ground.
水逐渐从地上渗走了。
《牛津词典》
2
If the former are greater, the lake is a surface-water-dominated lake; if the latter, it is a seepage-dominated lake.
如果前者较大，这个湖就是一个以表层水为主的湖泊；如果是后者，则是一个以渗漏为主的湖泊。
3
Note the word "net" measuring the actual amounts of groundwater seepage into the lake and out of the lake is a much more complicated matter than merely inferring their difference.