Lets see some lakes.

A small lake in the residential area. Poured several coats Enviorotex Epoxy for water after painting the bottom of the lake with different blues and greens.

Larry

From a modular group I used to belong to around the turn of the century:

Rusty

just kidding,  good luck with your layout build.......

a river scene on friend Clem's layout.....

the start of my lake attempt.....

Trainman your pond looks great.

I've just added and in the process of finishing this new section of my layout. I've named it the Little Horseshoe Curve Park. It has a water feature/pond with a small beach on the left, a boat dock and is surrounded by six (6) Lionel animated playground accessories. The track is elevated 2 inches after leaving the main line and is in the shape of a horseshoe...so I think it adds interest to the layout. Will also be adding some coach style lights for additional ambiance. Can't wait to see how the youngsters react to all of the animations...

Not exactly a lake.  In fact, I'm not quite sure what it is. But I needed to justify the bascule bridge in a very small space (and against a wall). Done with a piece of plate glass, spray painted underneath and with the waves painted on top with Mod Podge. Doubled in size with a mirror.

First rate work, men. 

This is on  friend's layout.