How to Protect Your Rainwater System Before a Hard Freeze

Hill Country winters are mostly mild, which is exactly why a freeze catches rainwater systems off guard. A few nights in the low 20s, or a week like February 2021, can crack a filter housing or split a pipe that has been fine for years. The good news is that a full tank almost never freezes solid. The damage happens in the small stuff, where water sits in thin pipe and plastic housings with nothing to keep it warm.

What freezes first

• Exposed pipe between the tank and the pump house, and any above-ground runs to the house.
• Filter housings. Clear and blue plastic housings crack when the water inside expands.
• The pump and pressure tank, especially in an unheated shed or on an open pad.
• The UV unit. The quartz sleeve inside is glass, and ice can crack it.
• Wet conveyance risers. If your downspouts feed an underground pipe that stays full between storms, the buried run is usually safe, but the vertical risers coming down from the gutters are not.

Before the first hard freeze

• Insulate exposed pipe. Foam insulation on every above-ground run, including short stubs and valves. Add thermostatically controlled heat tape on runs that take the wind.
• Put a heat source in the pump house. A small thermostatically controlled heater rated for well houses keeps the pump, pressure tank, filters and UV above freezing. Keep it clear of anything that can burn, and skip open heat lamps.
• Close up the pump house. Gaps around the door and pipe penetrations let cold wind straight in. Weatherstrip them.
• Drain wet risers. If you have a wet conveyance, find the low-point drain and open it when the forecast calls for a hard freeze, so the risers aren't holding water.
• Know where your shutoffs are. If a pipe does split, you want to kill the pump and close the tank outlet quickly, before a few thousand gallons end up on the ground.

If the power goes out

A freeze and a power outage often arrive together. With the power off, the pump and heater stop, and so does the UV lamp.

• Water that passes through an unpowered UV unit is not disinfected. If you draw water by gravity or on a generator while the UV is off, boil it before drinking. If you run a generator, put the UV on it along with the pump.
• When power comes back, give the UV lamp a few minutes to warm up, then run each tap for a minute or two to flush out water that sat in the lines untreated.

After the freeze

Walk the system once temperatures are back above freezing. Look for water around the filter housings, drips at fittings and wet ground along pipe runs. A cracked housing can hold while frozen and only start leaking once it thaws. If the pump runs or cycles when nobody is using water, there's a leak somewhere.

We're happy to walk your system before winter and flag anything exposed. Call Dripping Rainwater at (512) 829-5800 or request service online. For the year-round schedule, see how often a rainwater system needs service.