Town Hall Address 630 E Hopkins San Marcos, TX 78666 United States- Hays, Caldwell, Guadalupe County Website https://sanmarcostx.gov Fire District 512-805-2660 100 Carlson Circle San Marcos, TX 78666 United States Town Clerk 512-393-8000 630 E Hopkins San Marcos, TX 78666 United States Water 512-393-8383 636 E Hopkins San Marcos, TX 78666 United States Sewer 512-393-8383 636 E Hopkins San Marcos, TX 78666 United States Tax Collector 512-393-8170 630 E Hopkins San Marcos, TX 78666 United States County Hays, Caldwell, Guadalupe