Cats get dehydrated just as humans do. It’s important that your cat drink enough water throughout the day. Sometimes it seems a if my cats never drink water. There are some things that you could do to get them to drink more. The first thing that I would do is put several water bowls around the house. Vary the size and material of the bowls. and material of the bowls. Put the bowls in different places. Cats seem to get interested in anything that is “new” or “out of place.”  Try running water. My cats love to drink from the water faucet or the bathtub. They now make battery operated water bowls that actually run water.  You may try adding some food to the water. This does not work for my cats but it may for yours.  My younger cat ,Millie loves to drink the water that runs off of the plants after I water them. I don’t encourage this especially if you use plant food or bug repellent. It could actually make your cat sick.