Rainwater tanks and the water supply

SA Health says rainwater from a roof is generally safe to drink: if it is clear, tastes and smells of little, and comes from a well-kept system, it is unlikely to make most people ill. Beyond the tank, Yorke Peninsula Council runs small water schemes, a desalination plant and two water dispensers, set out below.

Where the water can come from

The roof and a tank

The guidance in the rest of this page. SA Health notes that rainwater holds no fluoride, and that where it is a household’s main drinking water, a dentist, school or community dental service, or the Australian Dental Association, can advise on other sources of fluoride.

A council scheme fed from the mains

At Balgowan, Black Point and Hardwicke Bay, water comes from the SA Water mains into a distribution scheme the council runs. Supplies are metered and charged at the current SA Water usage rate, with an annual service charge on each assessment the service reaches.

Desalinated seawater at Marion Bay

The council owns a seawater desalination plant at Marion Bay that supplies the local community and several businesses, with its own caravan park the largest user. Seawater comes from a beach well in the dunes, and the plant’s outlet sits under the Marion Bay Jetty. To buy from it, a swipe card comes from the caravan park manager’s office for a one-off $30, and water is $14.11 a kilolitre, as at October 2026.

Water dispensers

Two credit-card dispensers sell water at $3.15 a kilolitre, as at October 2026: one just off St Vincent Highway at Pine Point, across from First Street, and one on Yorke Highway about 6 km west of Warooka, before the Marion Bay Road turn-off. The council points to its Fees and Charges Register for current rates.

A bore

SA Health says a permit is needed before a bore is built, applied for through the Department for Environment and Water, and that a licensed water bore driller must install it. Water from a deep bore should have a chemical analysis before use, then be checked every two years; shallow bores are not generally recommended for drinking. Keep septic waste at least 50 metres from the bore.

Keeping tank water good to drink

SA Health’s rainwater page sets out the checks that keep a tank and its roof clean. As a list, they run like this.

• The tank is covered, and every opening except the inlet and the overflow is sealed. The inlet has a mesh cover and a strainer; the overflow has an insect-proof screen.
• Gutters are clean, with no ponding, and branches no longer hang over the roof.
• A first-flush diverter, which SA Health recommends, keeps the first rain after a dry spell, with its dust, leaves and bird droppings, out of the tank.
• No chemically treated timber or lead flashing in the roof catchment, and no overflow from an evaporative air conditioner or hot water system running onto it.
• No mosquitoes breeding in the tank. If you find them, find and close the gap they came through.
• Sludge on the tank floor is checked at least every two years and removed if it covers the bottom.

For people with weaker immune systems, such as the very young or very old, people with cancer or diabetes, organ transplant recipients and people who are HIV positive, SA Health suggests disinfecting drinking water first, by bringing it to the boil or fitting an ultraviolet light.

If the water is suspect

Regular disinfection should not be needed, SA Health says. When contamination is suspected, it gives a dose per 1,000 litres held: 40 mL of liquid sodium hypochlorite at 12.5% available chlorine, or 7 grams of granular calcium hypochlorite. Stabilised chlorine should not be used, and a chlorine taste may linger for a few days.

SA Health says routine testing of a household tank is not necessary in most cases. Any testing must be done by an approved provider against the Australian Drinking Water Guidelines, and if E. coli turns up, the tank should be chlorinated before the water is used again. If chlorinating is not an immediate option, SA Health says to use another source for drinking and food preparation, or to boil the rainwater before use.

Rainwater used for a commercial purpose, SA Health’s example being a food business, or for a community supply such as a caravan park, needs routine testing under a documented risk management plan. If you plan to let the house to guests, the council’s Environmental Health Officer can tell you whether that reaches your tank.

Building or adding a tank

SA Health notes a mandatory rainwater tank policy for new homes, and some extensions, built after July 2006, and suggests checking local health, building and planning rules before buying a tank. How big a tank a household needs depends on the rainfall and its pattern, the roof area and how much water is used, and SA Health points to published guidance for working it out. PlanSA lists water tanks among projects that usually need no development approval, except in protected areas where every project needs one. The council’s rules for the other end of the plumbing are in Septic systems and the CWMS.