AUSTIN, Texas (AP) — Residents of the Texas state capital are being ordered to boil their tap water before drinking after flooding in recent weeks filled the lakes that supply Austin with silt, mud and debris.

The city of Austin said in a statement Monday that the water needs extended filtration and treatment before it will be safe to consume.

Austin Water's more than 1 million customers have been told to boil water intended for drinking, cooking and making ice, and avoid drinking fountains. The San Antonio Water Service, which depends on artesian wells, is sending more than 5,000 gallons of drinking water in tankers to Austin.

There is no indication of bacterial infiltration. However, Austin Water warned that insufficiently treated water could contain bacteria, viruses, and parasites that can cause diarrhea, cramps, nausea, headaches and other illness. It said infants, young children, some of the elderly and people with severely compromised immune systems also would be at risk.

The boil-water notice prompted a rush on bottled water at grocery stores such as H-E-B, where shelves were emptied of supplies.

Starbucks shops suspended service of any coffee and espresso until the boil-water notice is lifted. It would continue to serve bottled and packaged products.

Mayor Stever Adler says that "the unprecedented rain and runoff through our entire lake system has simply overwhelmed our treatment capacity."

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