BMW 1989 water geting in control panel the air ducts

hi
i just been helping getting a old 1989 BMW back on the road i just about got it to start but there is a water leak i see and some of the water gets in throw the center control panel via the air ducts even into the back
also a bit at the back of the engine by the look of it by there is lots coming from inside.
if it is the heater is there a way to get round it as i don't need one as I'm used to driving cold cars
it is missing as it slows down ans stalls on tick over but i have not looked at that as i now it could be lots of things but common problems with this year when they been sitting for 6 months would help too thanks would be grate help