Nashville sits in the USDA's Nashville Basin, where Central Tennessee soils are clayey with slowly permeable layers - which is why pool excavations here need drainage and backfill attention. The towns around it spread across five counties, each with its own water utility and its own codes office, so requests are routed town by town instead of treating the metro as one market.
Davidson County · water from Metro Water Services
Williamson County · water from City of Franklin Water Management Department
Williamson County · water from City of Brentwood Water Services
Rutherford County · water from Murfreesboro Water Resources Department
Sumner County · water from Hendersonville Utility District
Sumner County · water from Gallatin Public Utilities
Rutherford County · water from Smyrna Utilities
Wilson County · water from West Wilson Utility District
Water here is not one utility. Metro Water Services covers Nashville and Davidson County, while Franklin, Brentwood, Murfreesboro, Hendersonville, Gallatin, Smyrna and Mount Juliet each sit on their own city system or independent utility district, so drain and refill rules differ town to town. Metro Water's latest published guidance asks customers to water on a voluntary odd/even schedule between 7 p.m. and 4 a.m.