The poor conditions that allowed the 2008 cholera epidemic to flourish still persist in the capital's townships, said the report titled "Troubled Water: Burst Pipes, Contaminated Wells and Open Defecation in Zimbabwe's Capital."
Piped water throughout Harare is erratic and sometimes as little as a few hours every two weeks.
In one township house, there was one toilet for 21 people, but no water to flush it, said the report. When there is no water at all, people have no alternative but to defecate outside, the report said.
"Having to defecate openly jeopardizes people's health, dignity . and safety," it said.
"Poor sanitation practices, including open defecation . leads to outbreaks of waterborne diseases such as cholera and typhoid in communities," the report said.
Garbage containing human waste such as dirty diapers is allowed to pile up on township streets and raw sewage flows freely along streets and up to doorsteps, putting residents at risk of diseases. People must wait at a well for up to five hours a day and violence frequently erupts when lines are especially long.
Harare's township water system is broken down and long-time President Robert Mugabe's government "isn't fixing it," Human Rights Watch said. Corruption and mismanagement at the local and national level worsen the problem, it said.
Fees paid by residents for water services are not being ploughed back into the water system and money is diverted to other uses, creating shortages of chemicals to produce potable water.
"People are being made to pay huge bills for water that is rarely available and when it's available it's dirty leading them to fall sick," Dewa Mavhinga, a researcher with the group said Tuesday. He said two-thirds of the revenue collected from residents is used to pay top city council officials' salaries, allowances and to buy luxury cars.
Harare's water pipes and sanitation facilities have not been upgraded since the country gained independence from Britain in 1980 when the city catered for 600,000 people and now it has a population of nearly 4 million, Mavhinga said.