Hi trishh
you are right to connect water to emotional issues and its one of the universal signs with same meaning from culture to culture. Stagnant water also means being "stuck" emotionally and that its time to "shift gears".
There is also meaning of "lake" - Egyptians associated lake dreams with inner realms and used to have special "lake ceremonies" and in Celtic traditions lake was "the land of the dead", - inner, mysterious realm, deep unknown place.
If it was me interpreting your husband's dream, in addition to emotional issues, I'd suggest for him to take time, be still and to explore and deal with them in dept.
Hope this will help
Love Lara