Water treatment in Marble Falls, TX has to survive the city's own supply interruptions. On July 15, 2025, the City of Marble Falls told everyone on its water system to boil what came out of the tap. The July 4 flood had pushed a load of sediment down the Colorado River into Lake Marble Falls (the city manager's phrase for the lake that week was "chocolate milk"), and the downtown plant east of the US-281 bridge could not keep the finished water clear enough. One reading hit 1.65 NTU, only 94 percent of that month's readings stayed under the 0.3 NTU line, and the 2025 water quality report lists two July turbidity violations. The notice lifted on the 18th. Meadowlakes, which draws through a gravel bed beneath the same lake, stayed clear through the same week.
That is the thing about Marble Falls water: it follows the weather. A flood is a water-quality event here as surely as a drought is, because the 605 acres behind Max Starcke Dam pass the Colorado River through town with very little time to settle. Treatment for a Marble Falls home has to be built for the wet week, the dry year and the hot months between them.
What a flood does to a pass-through lake
Lake Marble Falls holds about 7,300 acre-feet at a near-constant 737 feet, with Wirtz Dam above and Lake Travis below. Whatever the upper Highland Lakes release arrives at the city's raw-water intake on Lakeshore Drive within hours, sediment included. The city rebuilt that intake in 2024 and raised it above the 100-year flood line, keeping once-a-week watering rules in place from mid-2024 until June 18, 2026 while the work went on, and the July 2025 event still produced a boil notice. October 2018 was harder on the system: that flood damaged the Starcke Dam intake and the wastewater plant near Johnson Park, and the lake was drawn down seven feet in February 2019 and again from October through December 2022 to repair the debris damage.
For a house on city water, the practical lesson is a point-of-entry sediment filter ahead of everything else and, for households that want a layer the city plant does not provide, ultraviolet disinfection right behind it. We install Viqua UV systems for exactly this purpose; our water purification page covers how UV works and when it is worth adding. The same logic applies twice over on the South Road and Lakeshore lots east of the bridge and on Lake LBJ, where owners pump raw lake water under LCRA domestic-use contracts. That water has no plant behind it at all, and a flood puts the river straight onto the intake screen.
What a drought does to the wells around town
Inside the city limits nearly every home is on the utility, roughly 3,200-plus connections against about 3,500 housing units. Outside the limits, on the two-to-eight-acre tracts of Summit Springs off TX-71, along FM-1431 toward Mormon Mill Road and down CR-401, water comes from private or shared wells in the Ellenburger-San Saba and Marble Falls limestone. Those aquifers are karstic: quick to recharge after a rain, quick to fall when it stops, and hard in any weather. West of US-281 along the lakes the rock turns to granite, and wells there yield under 25 gallons a minute; the groundwater district's own description is "suitable only for domestic use."
The 2022-23 drought showed what that means in practice. Burnet County's Palmer hydrological index reached -4, the most severe category; the Central Texas Groundwater Conservation District declared Stage 4 in June 2022 and asked for a 30 percent cut; and monitor wells in the Ellenburger-San Saba, Trinity, Hickory and granite-gravel aquifers hit all-time lows across the county, with one south-county well dropping twenty-four feet in a single year. The district was logging 40 to 50 new well applications a month at the same time. A well pulling from the bottom of its water column pumps sand, entrains air and concentrates minerals, so the treatment side has to include storage, sediment handling and a hardness plan sized to a low flow rate. Where a well reaches the Hickory sandstone, the state water board says plainly that iron above the drinking-water standard is common and that radium comes with it. Our iron and sulfur removal page explains the air-injection and oxidizing systems that handle the staining; we test for the rest before recommending anything.
What the summer heat adds
Between floods and droughts comes a Marble Falls July, and the lake responds like any warm, shallow Highland Lake: algae, an earthy geosmin taste, and since December 2019 zebra mussels. The city meets that at the intake with chlorine dioxide for taste and odor and a copper-based product, EarthTec QZ, to keep the mussels off the pipes, a change that triggered extra lead-and-copper sampling, which came back at a 90th-percentile copper reading of 0.12 ppm. Disinfection is chloramine, averaging 1.84 ppm in 2025 with a range of 0.5 to 4.5, and total trihalomethanes averaged 27.8 ppb. None of that is a health alarm; all of it is a taste-and-chemistry problem with a known fix. Chloramine is the reason a standard carbon block does little in this town (the chlorine-ammonia bond needs catalytic carbon), and the reason a reverse osmosis unit at the kitchen sink needs a chloramine-rated prefilter to protect its membrane. Our water filtration page walks through the cartridge, carbon and catalytic-carbon options for chloraminated city water, which is what Marble Falls, Meadowlakes and Cottonwood Shores all deliver.
Hardness is the constant underneath the seasons: 185 mg/L as calcium carbonate in the 2025 report, or 10.8 grains per gallon, from 41.8 mg/L of calcium and 19.6 of magnesium at a pH of 7.4. Since 2024 the city has been able to blend in Ellenburger groundwater from the two Capstone Ranch wells it bought south of town, and limestone well water does not make that blend any softer.
Two thousand new roofs, none of them softened
Thunder Rock, the 1,100-acre master-planned community northwest of the US-281/TX-71 junction, is platted for 1,966 single-family lots, with D.R. Horton and Lennar building from the low $290,000s. Gregg Ranch adds 707 lots south of TX-71; Roper Ranch East and Flatrock Crossing bring 555-plus more homes and an elevated water tank approved in August 2026. All of it is on city water and sewer, and, as production homes go, these close without a softener, so the first scale on a tankless heater shows up early on 10.8-grain water. Marble Falls is a working town rather than a lake-estate market: median household income is $57,925 and nearly six in ten households rent. What we bring to a Thunder Rock or Gregg Ranch garage is a right-sized softener and catalytic carbon, not the largest system on the truck, and property managers, restaurants and medical offices along the US-281 corridor get the same test-first approach at light-commercial scale.
Older stock needs a different read. Twenty-one percent of the city's homes predate 1980 (the downtown grid from Main Street to Avenue N and the 1960s-80s lake cabins on the south shore) with galvanized and copper lines, and the 2025 sampling found one site over the lead action level. There, an under-sink RO faucet earns its place before any whole-house unit does. On the acreage side, every septic lot needs a demand-initiated-regeneration softener or a brine bypass under Texas on-site sewage rules, and within LCRA's 2,200-foot band around Lake Marble Falls and Lake LBJ, LCRA is the agency that permits and inspects the septic system itself.
Softening city water and well water
A water softener in Marble Falls, TX has two different jobs depending on which side of the city line you live on. Inside the utility, the 2025 water quality report puts hardness at 185 mg/L, about 10.8 grains per gallon, which is the scale you see on shower glass and inside a tankless heater. On the acreage subdivisions outside the CCN, wells drilled into the Ellenburger and Marble Falls limestone usually test harder than that, and those homes are on septic, so we install water softeners that regenerate on demand rather than on a timer. Either way the install starts with a hardness test at your tap, not a guess from a map.
Up US-281 from Spicewood
We are based in Spicewood, about 25 road miles and 35 to 40 minutes from downtown Marble Falls (TX-71 west, then US-281 north across the Lake Marble Falls bridge), and the Thunder Rock, Gregg Ranch and Flatrock Crossing corridor at the junction is about five miles closer. Absolute Water Solutions has installed and serviced treatment systems since 2003, more than 1,000 of them, with every job done by our own crews; we hold TCEQ water treatment license WT001370 and are insured. Visits are scheduled Monday through Friday, 8am to 5pm, and each one starts with a test of your water at the tap or the wellhead. Request a free estimate or call (512) 587-8188, and tell us whether you are on the city system, a well or the lake.