Make up a chopped meat or fish based soup and freeze it in an ice cube tray. The resulting ice cubes will not only cool your pet's water, but flavor it too. This flavoring might entice kitty to drink more fluids because of the appealing smell and perhaps masking the odor of minerals and/or chlorine in your water source. A cup of either fish or chopped meat cooked in about a quart of water for about 30 minutes and strained to remove the meat or fish should be about right, but you can experiment for the combination that works for you and your pet. The meat or fish strained out can be mixed with the regular food over a period of two or three feedings.
Try changing the shape of the water bowl. Some pets like a deep bowl and others a wide one that does not touch their whiskers when they drink. A heavier bowl that will not move when kitty nudges it may be helpful. A little experimentation may pay off in increased water consumption.
Add a few ice cubes to the water dish, especially in the summer.
Remember to provide fresh water. Consider changing it three times a day.