Just not drinking enough fluids can contribute to urinary tract infections. You need the constant flushing out of the bladder in order to prevent a urinary tract infection from taking hold. If you are dehydrated, you will fail to flush your bladder frequently, leading to frequent UTIs. You need to drink at least half your body weight (in pounds) in ounces of liquid (preferably water). For example, if you weigh 150 pounds, you should drink 75 ounces of water or other acceptable liquid in a given day. This keeps you voiding steadily throughout the day, flushing out any bacteria that might be lurking in the bladder.