Is the water coming from the T&P Valve or, the tank itself.
It makes a big difference as to wether or, not the water heater needs replacing.
If it does need replacing I would reccommend a Bradford-White or, Rheem/Ruud as a replacement.
Under no circumstances would I purchase a gas water heater from Lowes they sell Whirlpool which are absolutely without any doubt the worst of the worst. In their latest move to decieve their customers as the word about Whirlpool is spreading they are selling other brands of American Water Heater Company products in their stores. Don't let them fool you! It's the same junk with a different sticker on it!