Whole House Water Softeners in Lewisville

Of the towns around Lewisville Lake, Lewisville alone treats the lake's water itself. The federal facility list for the city system (TX0610004) shows two raw water intakes on Lewisville Lake feeding the city's surface water treatment plant, with 2 million gallon clearwells, alongside three connections carrying Dallas Water Utilities water and one carrying Upper Trinity's. From there the water moves through the Eastside, Southside, Midway and Castle Hills pump stations, each with ground storage, and up into elevated tanks on Windhaven Parkway, Moccasin Trail, South Valley Parkway, Bellaire and at Castle Hills. All three sources are reservoir water from the same river system: Dallas's Elm Fork and Bachman plants take Ray Roberts, Lewisville and Grapevine lake water, and Upper Trinity's Thomas E. Taylor plant, also in Lewisville, runs Lewisville and Ray Roberts water through ozone and chloramine.

The figure on this page, 141 mg/L of total hardness, is the average the city reports in its 2025 water quality report rather than a single sample. On the USGS scale 121 to 180 is hard, so Lewisville sits squarely in the hard band, at about 8.2 grains per gallon. It also sits inside the range Dallas published for its own system in a December 2023 memorandum, 120 to 155 mg/L, and that is what you would expect: the Dallas water entering Lewisville's mains and the water the city treats itself come out of the same lakes. Upper Trinity's 2025 report prints no hardness value, so the third source carries no number of its own, but it is the same Lewisville Lake water through a different plant. Hardness here is the calcium and magnesium the reservoir takes on from the ground it drains; it is a mineral characteristic, not a contaminant, and the reports in this chain treat it as one.

Because Lewisville blends three deliveries of the same kind of water, the variation across town is smaller than in a well-and-lake district but not zero: a Castle Hills tap served through its own pump station and 1.5 million gallon elevated tank and a tap near the Eastside station can see different proportions of Dallas and city-plant water, and the lake itself changes with rain and drought through the year. At 141 mg/L the signs listed above, white scale on fixtures, film on glassware, soap that will not lather, are the expected result rather than a fault, and they will show up in every part of the city. A softener for Lewisville should be sized for the upper part of the Dallas range, 155 mg/L, about 9 grains, rather than for the 141 average, so it keeps up in a dry summer; a free water test gives the exact grains at your tap on the day you ask.

Sources: City of Lewisville 2025 Water Quality Report · U.S. EPA Envirofacts SDWIS: water system facilities for TX0610004 · City of Dallas memorandum, December 1, 2023: Community Water Fluoridation Follow Up · Upper Trinity Regional Water District: Water Treatment and Delivery · Upper Trinity Regional Water District 2025 Consumer Confidence Report