LAKES: impassable bodies of water that do not touch the table edges. Rivers may flow into or out of them. Available to all but Dry Regions. Only one is allowed per battlefield. Cannot be crossed by roads (obviously). (Large bodies of water, such as Lake Trasimene, are already represented as waterways. Lakes represent smaller bodies of water, such as that behind the Polish forces at the Battle of Tannenberg in 1410)
Are your Lakes as per DBMM? Similr to Waterways but don't cover the entire base edge and not quite as deep? I think between 1/4 and 3/4 would be a good length.
I’ve never bothered to look at the DBMM terrain types. I envisage a Lake to be an impassable piece of Area Terrain that obeys all the Area Terrain rules.
Soooo...Minimum size = 1½ x 3 BW (i.e. twice as long as wide, because they are not a Gully). Maximun size = 4½ x 4½ or 3 x 6 BW. And with a 1 BW gap between them and other Area features or a table edge. But Linear Terrain features , such as Waterway, River or Roads, can actually touch a Lake. However, for road placement see fanaticus.boards.net/thread/731/road-placement