Taps were dry across a wide swath of Rio de Janeiro on Tuesday, some for nearly a week straight, prompting a flurry of criticism of the state water company and forcing some desperate residents of this Olympic city to fill plastic bottles with water from streams.

Rio's Cedae water utility cut off service to nearly a dozen Rio neighbourhoods Thursday as part of routine maintenance on a treatment plant on the Guandu River, the main water source for the city of six million.

The utility had said in a Thursday statement that it could take up to 72 hours for service to be restored. But long after that period passed, many parts of the city remained without water. Cedae later pledged that water would be restored to all households by the end of Tuesday.

The 11 neighbourhoods affected include beachfront Leme, chic Santa Teresa, stately Flamengo, as well as Maracana, home to the soccer stadium where next year's World Cup final will be played.

A recent cover of O Globo newspaper showed enterprising residents of the upscale Cosme Velho neighbourhood filling large plastic bottles from a fresh-water fountain. Many apartment buildings have relied on water delivery trucks to keep their storage tanks full.

Rio's consumer protection agency began investigating allegations of price gouging after O Globo reported some trucks were charging as much as 4,000 reais — about $1900 — for 20,000 litres of water. The companies, which normally charge around $430 per shipment, pay Cedae around $30 for the water, the report said.

Exasperated Rio residents took to Facebook and Twitter to bemoan how much time had passed since their last shower and criticize state officials.

The debacle, less than a year ahead of the World Cup and two-and-a-half years before the city hosts the 2016 Olympic games, underscores its problems with basic services such as water and sewage treatment.

Residents who can avoid drinking tap water for fear of contamination and nearly half of the city's households aren't hooked up to sewage lines, meaning that tons of raw sewage flow into the city's rivers, lagoons and onto its beaches daily.