please help, my dogs a wuss and its making her unheatly

My dog Elvira is a 12 year old black labrador and ever since she was a 
little puppy she's been really scared of water and guns..and loud 
nosies, and cats, and another animals and probably a million other 
things too, but shes really a sweet dog and anyway even though she's 
getting old now I've noticed shes groaning a lot and looks depressed 
sometimes and I think it's because, well she's pretty fat, and I believe 
it's because she doesn't drink enough water. If I take the water bowl 
over to her she always looks away.  Can someone please tell me how to 
get her to drink more water and not be afraid of it? I take her for 
walks as much as possible but she still doesnt drink much. Is there any 
other ideas? any food I can feed that will make her drink?

Thanks,
Anton.