Permanent Wet Area in Backyard

So I know this isn't probably the app for this type of question, but you ladies are so knowledgeable that I thought I might try. I've googled for answers but nothing useful appears. I moved into my rent house in April. It is a very old house...built in the 1930s... I know the girl who lived here before me, and she said that the landlord doesn't fix anything... she had hounded him for two years about fixing part of the roof but he never did. Well, when I moved in I noticed that there was a small wet area in the backyard, because the grass was green there and it wasn't anywhere else. It doesn't smell like sewage. My SO thought he had heard of people letting their water line open to the backyard to keep it watered. Idk. It didn't smell like sewage so I wasn't too worried about it. Last month, my water bill was about $170. Before then it had only been $60ish. The next bill I got after the $170 one was $70ish. In the last month I have also noticed that that water spot has gotten bigger and now there is actually standing water in the yard where my dogs have dug holes into the wet area. Do you think I have a burst water line? If so, would I need to call the town and let them know, or should I just dig it up on my own and see if my dad can help me fix it? (He is a very handy man and has done plumbing before.) I know I should just ask my dad what he thinks, but he is busy and I don't want to bother him if I don't have to. I can't pay for a company to fix it for me, and I don't think my landlord will care. I could just use some advice, thanks!!