I had the same problem this winter. With all the snow and heavy rain I now have multiple bubbles and the liner pulled away from my steps. I had the pool company who installed it (it's only 2 years this summer) come out they gave me the same advice. They will empty the water out of the low end and fix the problem. The soil in my area is clay so I'm hoping this isn't a longer term problem with the drainage in my backyard. If so I'm sure it will be big bucks to install a drainage system. BTW the quote I got was under $500 for the fix. Not happy about it but what can you do with a winter like we had.