Plumbing in Princeton, TX: Water Providers, Leaks and Permits

Three water providers: check your bill

Princeton has grown very fast: 6,807 residents in 2010, 17,027 in 2020, and an estimated 25,229 in the 2020 to 2024 American Community Survey. The median Princeton home was built in 2014, and about two in three were built in 2010 or later (Census data).

Water service in the area is split between three utilities, and the name on your bill decides who you call:

• City of Princeton: the city's Water Division keeps staff on call around the clock; after hours, call 972-736-2711. The Water Division's main line is 972-734-2416, extension 8 (Water Division).
• Culleoka Water Supply Corporation: (972) 736-2592, 3388 FM 982. It buys its water from the North Texas Municipal Water District (Culleoka WSC).
• Milligan Water Supply Corporation: main line 972-542-1143, after-hours emergencies 972-837-6840 (Milligan WSC).

The city's utility billing page tells Culleoka and Milligan customers to contact their own supplier (utility billing). The City of Princeton treats sewage for many Culleoka and Milligan customers too, and since October 1, 2025 those customers have been billed for sewer by usage through their water provider (water and wastewater rates).

Culleoka WSC had posted Stage 2 water conservation as of August 2026 (Culleoka FAQ). If you're a Culleoka customer, check its site for the current stage before running irrigation.

Who fixes which leak

The City of Princeton says property owners are responsible for private water systems from the outside water meter into the home. The shutoff valve between the meter and the street belongs to the city and is for city staff only; to have water shut off at the meter, call 972-734-2416, extension 8 (city winter guidance). Your own shutoff, usually near where the line enters the house, is the one to know. See how to shut off your water.

Repairs to lines on your property are typically not covered by the city. The city offers an optional service line warranty through a third-party company (service line warranty program). It's a private product, so read what it covers before buying.

Leak adjustments

Because the calculation uses the two months after the repair, the leak has to be fixed promptly for the average to reflect normal use. The city also lends free leak detection tools from Public Works, 255 E. Monte Carlo Blvd. (water). Our high water bill guide walks through the meter test.

Permits in Princeton

Most construction and remodeling work in Princeton needs a permit, and the city's FAQ names sewer and water line repairs specifically. Two local rules are worth knowing (permit FAQ):

• A plumbing permit can only be pulled by the homeowner or a licensed master plumber.
• A plumbing permit is needed before the city will release gas service to Atmos Energy, which matters for new gas water heaters and gas lines.

Water heater replacements appear in the city's permit records as plumbing permits. Contractors must register with the city. Apply through the city's EnerGov self-service portal; Building Inspections is on 972-736-6169, option 4 (building inspections). Princeton has adopted the 2021 International Plumbing Code with local amendments (adopted codes).

If a plumber offers to do permitted work without a permit, or to pull it under someone else's license, that's a reason to look elsewhere. See choosing a plumber.

Water quality

City of Princeton water is surface water from NTMWD, mostly from Lavon Lake. The city's 2025 report shows lead and copper results well under their limits, with no violations (2025 water quality report). NTMWD's 2025 report lists total hardness of 96 to 200 ppm for its Wylie plant, roughly 6 to 12 grains per gallon, with chloramine disinfection (NTMWD 2025 report). Expect scale on fixtures and sediment in water heaters; see our hard water guide. The city publishes its lead service line inventory online.

Growth and capacity

Princeton's growth has strained its water, wastewater and road systems. The city adopted a temporary moratorium on new residential development in September 2024, citing that capacity (city news), later extended into 2025, and a 2026 water and wastewater master plan update went to council in August 2026. For existing homeowners, the practical effect is mostly on the city side, but it's one more reason to fix leaks and irrigation problems quickly.

Watering rules

From April 1 to October 31, City of Princeton customers may run spray irrigation no more than twice a week, and controllers must not run between 10 a.m. and 6 p.m. From November 1 to March 31, it's once a week at most. No spray irrigation in the rain (water). Culleoka and Milligan customers should follow their own provider's rules.

Useful Princeton numbers

• City of Princeton water, after hours: 972-736-2711
• City Water Division: 972-734-2416, ext. 8
• Culleoka WSC: (972) 736-2592
• Milligan WSC after-hours emergencies: 972-837-6840
• Building Inspections: 972-736-6169, option 4
• Gas smell: leave the building and call 911 or your gas utility from outside

These are official city and utility lines, not plumbing referrals. We're not affiliated with the City of Princeton or either water supply corporation.

Getting a plumber in Princeton

Princeton's city addresses use the 75407 ZIP code, and the city is about 8 miles east of McKinney on US 380. We accept requests from Princeton addresses. Each plumbing business sets its own travel area, so whether a particular plumber covers your street depends on the business, and we'll tell you if we can't find a match. For McKinney's own rules, see our McKinney service area page.