Whole House Water Softeners in University Park

University Park's supplier was built for a lake that did not yet exist. The Dallas County Park Cities Water Control and Improvement District No. 2 was created by the state in 1938 at the request of University Park and Highland Park, took water rights to a Denton Creek reservoir of 50,000 acre-feet in 1946, and in 1947 agreed with the Corps of Engineers to help pay for Grapevine Lake alongside the City of Dallas, with a district share of $607,000. The Corps built the dam between January 1948 and June 1952, and the district began taking Grapevine water in 1954; it became a municipal utility district in 1973. Today the Corps releases water at the district's request into Denton Creek, it runs down into the Elm Fork, and the district catches it at Ski Lake and pipes it to Regal Row. Treated water reaches the two cities through a 36-inch main along Denton Drive and Mockingbird Lane, and University Park holds it in two elevated tanks of 2 million gallons each for about 9,000 accounts.

The chemistry is what sets this water apart from its neighbors'. At Regal Row the district adds lime slurry and ferric sulfate, and it says it tracks hardness specifically to judge its lime softening process; the city's own supply page describes the lime and ferric step as softening the water. The city's 2025 report, published in June 2026, prints no hardness row and no other secondary constituents, so this page shows no figure for University Park. The nearest published number is Highland Park's, on the same plant's water: its 2025 report gives tap water hardness of 42 mg/L on average in a range of 28 to 93, which is soft to moderately hard on the USGS scale. That figure is Highland Park's, not University Park's, and this page does not borrow it. By contrast the city of Dallas, which treats Grapevine water too but at its Elm Fork plant, puts its own hardness at 120 to 155 mg/L.

At a University Park tap the water is lake water that has been through a softening plant, and the reasonable expectation is a figure well below Dallas's, but an expectation is not a measurement. The district's membranes, added in 2013, remove particles, not dissolved calcium and magnesium; that work is done by the lime, and the result at the faucet shifts with the lake, the season and the dose. A softener here, if one is wanted at all, should be sized to the top of whatever the free water test shows across the year, and that test is the only way to get University Park's own number, since nothing the city or the district publishes prints one.

Sources: Dallas County Park Cities Municipal Utility District, About · Texas Water Development Board, Grapevine Lake · City of University Park, Water Supply Information · City of University Park, Water Distribution · City of University Park 2025 Water Quality Report · Town of Highland Park 2025 Drinking Water Quality Report · City of Dallas memorandum, December 1, 2023