Tap or lake water is not very conductive. Here is a snip from Wiki:
In many cases, conductivity is linked directly to the total dissolved solids (T.D.S.). High quality deionized water has a conductivity of about 5.5 μS/m, typical drinking water in the range of 5–50 mS/m, while sea water about 5 S/m (i.e., sea water’s conductivity is one million times higher than that of deionized water).
So fresh water is about 100 to 1000 times less conductive than sea water.