Every faucet in Horseshoe Bay pours Lake LBJ, and the membranes at the city's Central and West plants were never designed to pull calcium out of it. So when someone looks up a water softener in Horseshoe Bay, TX, the useful starting figure is the one the city last printed: 167 mg/L of hardness in 2018, 175 in 2019, 195 in 2020. That works out to 10 to 11.4 grains per gallon, and the direction was up. Since 2021 the utility's reports have followed a state template that leaves hardness out entirely, so nobody outside the plant has a current number. We take one at your kitchen tap before recommending anything. (General softener mechanics, sizing and repair are covered on our water softeners page; this one is about what changes on the south shore of Lake LBJ.)
Sizing for a two-person house at 11 grains
The usual softener pitch assumes a family of four. Horseshoe Bay's median resident is 64.6 years old, and a lot of houses here run two people for part of the year. At 11.4 gpg, a couple using about 150 gallons a day asks the resin to remove roughly 1,700 grains daily, around 12,000 a week. A one-cubic-foot bed (nominally 32,000 grains) handles that on a moderate salt setting and regenerates every two weeks or so. Where we go bigger is not headcount but plumbing: a lakefront custom home in Escondido or Summit Rock with a tankless heater, a body-spray shower and a full house of guests every holiday needs flow rate more than capacity, and that usually means 1.5 cubic feet on a 1-inch valve.
Keep the softener off the sprinklers
Between 63 and 69 percent of what the city produces never reaches the sewer. It goes onto lawns, beds and landscaping along the fairways. The city has been in Stage 2 conservation continuously since June 2015 (twice-weekly watering by address, nothing between 10 a.m. and 7 p.m., no watering on Mondays), and every irrigation system carries a backflow preventer on a five-year test cycle. The practical point for a softener is that the tie-in has to sit downstream of the irrigation tee. Softened water on turf wastes salt, leaves sodium behind in thin granite soil, and in summer (when the city pumps 82 to 93 million gallons a month against about 32 in February) would force regenerations every few days. In older Horseshoe Bay Proper houses, where the irrigation line and hose bibs were sometimes teed off after the spot a retrofit loop went in, we trace the plumbing before cutting in.
Chloramine, the fall burn, and your resin
Both the city and Llano County MUD #1 in Blue Lake Estates disinfect with chloramine, averaging about 2 mg/L, and the city's residual reached 5.4 mg/L at points in 2025. Each fall the city switches to free chlorine for a month to scour its mains (September 28 to October 27 in 2026). Softener resin is a polymer, and a steady diet of oxidant slowly swells and softens the beads until they pack down and pressure drops. A catalytic carbon tank ahead of the softener takes that load off the resin all year, including the conversion month. The 2018 report also showed aluminum carryover from alum coagulation averaging 0.33 mg/L, and a sediment stage in front keeps that floc from coating the resin bed.
Drains on granite, brine on septic
Much of the city sits on thin soil over Llano Uplift granite, the same bedrock the original mains were laid on. A softener needs somewhere to send its regeneration water, and burying a new line across a rock yard is rarely practical. We plan for an air-gapped discharge into an existing laundry standpipe or floor drain inside the garage, which also keeps the equipment out of view in a community with POA architectural review. Bay Country is the in-town exception: its 1995 acreage lots are on septic, and state rules allow brine into an OSSF only from a demand-initiated unit, so those installs are always metered.
Where the work concentrates
- Horseshoe Bay Proper, West, Applehead and Pecan Creek (1971 through the late 1990s): original copper, water heaters that have carried decades of 10-grain scale, and garage loops that may still hold a timer unit well past its life.
- Summit Rock, Tres Vistas, The Parks and Siena Creek: builder pre-plumb loops that were never filled, usually the simplest installs in town.
- Resort condos and attached homes (about a third of the housing): shared risers usually rule out a whole-house unit, so the answer there is often not a softener at all.
- Deerhaven and Sandy Harbor: wholesale city water, smaller lake houses and manufactured homes where a compact cabinet softener fits the space.
Salt, sodium and a retirement-town kitchen
Softening trades each grain of hardness for about 8 mg/L of sodium, so 11-grain lake water leaves the softener carrying roughly 90 mg/L more sodium than the 22 to 32 the city reported at the plant. For households watching sodium, potassium chloride works in the same brine tank at a higher cost per bag, or a reverse osmosis faucet at the kitchen sink removes most of it from drinking and cooking water.
Timing a Horseshoe Bay install
Winter is the easiest season: irrigation is off, lake organics are at their lowest, and many seasonal owners are in town. We come out from Spicewood, about 40 minutes by TX-71 and RM 2147, Monday through Friday from 8 to 5, and group visits by neighborhood. The wider picture of the city's water (Llano River floods, disinfection byproducts, the wells on the ranch fringe) is on our Horseshoe Bay page. Absolute Water Solutions has installed with its own crews under TCEQ license WT001370 since 2003. Request a free estimate and we will start with the hardness number.