The San Antonio Water System is threatening to shut off water service to two apartment complexes because of unpaid debt. On Tuesday, SAWS alerted the tenants of six apartment complexes that their water may be shut off next week. Two of the complexes had more than 200 units. By Thursday, all but two of the complexes had paid the utility what they owed. SAWS cut off the water last month to four apartment complexes that were behind on their payments, and ultimately collected.