Two kinds of ground
Limestone west of I-35, blackland clay to the east
The same pipe fails differently depending on which side of the interstate it is buried.
The Balcones Escarpment runs north to south through the middle of the county, from Jarrell through Georgetown to Round Rock. The Handbook of Texas describes hilly brushland west of that line and flat to rolling blackland farm country east of it. Plumbing in each half wears out in its own way.
On the west side, shallow limestone sits under thin soil. A yard water line or sewer lateral that would take a shovel elsewhere can need a rock saw here. The Texas Water Development Board calls Edwards groundwater hard but fresh, and that hardness shows up as scale in tank heaters, tankless units and toilet fill valves.
East of I-35 the dark clay swells after rain and shrinks in a dry August. Slabs ride that movement, and drain and supply lines under them crack at the joints. Most of the newer subdivisions from Hutto out to Taylor sit on this ground.
Then there is February 2021. Winter Storm Uri split attic lines, exterior-wall pipes and hose bibs across the county, and two of our Google reviewers describe that week from their side. Rural homes had a second problem, because a frozen pressure switch or exposed well line leaves the house dry even when the indoor pipes survive.
Outside city limits
Wells, septic tanks and rural water districts
Who supplies the water, and who handles the waste, changes from one road to the next.
Cities cover the middle of the map, but the fringes belong to water districts. Jarrell-Schwertner WSC serves the north end into Bell County. Manville WSC and Jonah Water SUD serve parts of the Hutto area, and plenty of acreage homes still pump from their own wells.
Septic is the other half of rural plumbing. The county's On-Site Sewage Facilities program, run by the County Engineer's Office under TCEQ authority, permits and inspects septic systems everywhere except inside the City of Austin. The county's own rule of thumb is that an unincorporated or ETJ address probably needs one.
Typical rural calls: a pressure tank that short-cycles, a septic line that backs up, a yard line leaking under pasture, a heater scaled solid by well water. Each nearby town has its own page: Jarrell, Liberty Hill, Weir, Serenada and Florence.
On the south end, Round Rock, Cedar Park, Leander and Brushy Creek are suburban, with MUD and city systems and their own repipe and slab-leak patterns.
