Shade Changes the Math
Why West Lake Hills Pools Need a Different Program Than the Rest of Austin
The water is the easy part. West Lake Hills proper is served by Travis County WCID 10, which buys its water from the City of Austin, and Rollingwood, Davenport Ranch, and Lost Creek are on Austin Water directly. Either way it is the same Colorado River water: moderately hard, 70 to 126 ppm total hardness, about 4 to 7 grains per gallon. It does not stay there. Evaporation leaves calcium behind every summer, cal-hypo shock adds more, and a pool that has never been partially drained commonly reads 300 to 500 ppm after two or three seasons. Shade slows that climb without stopping it.
What shade takes away in evaporation it gives back in algae. Chlorine survives longer under an oak than in open sun, so owners here often carry a decent residual and still get green film on the steps. The cause is circulation, not chemistry: a still, shaded corner with a weak return and a layer of leaf tannin is a nursery. So our 78746 program is built around brushing every wall, bench, and step every visit, keeping free chlorine at 1 to 3 ppm with cyanuric acid at 30 to 50 so it stays available, and aiming returns through the dead spots the original builder left behind.
Then the lots. Canyon sites off Camp Craft Road and Redbud Trail come with steep driveways, terraced yards, and equipment pads a terrace or two below the water. Many of these pools went in between the 1960s and the 1980s and have been remodeled at least once, so the plumbing is non-standard, the DE filter may be a model nobody makes parts for, and whoever understood the valves moved away years ago. Rollingwood is the flatter counterpoint: smaller lots, 1950s to 70s homes, updated pools, and the same live oaks overhead dropping catkins from March into April and leaves through the fall.
