For years, thousands of Opa-locka water customers have railed against irregular and inflated bills, accusing the city of running a deeply flawed utility system undermined by leaky pipes, inaccurate meters and corrupt management.

Now, they have some compelling proof: A consultant retained by Opa-locka to survey the city’s 5,800 water meters has found that only half can be read at all and just one-third with any accuracy. And that assessment excludes about 900 meters that could not be accessed or located, because of overgrown landscaping and other reasons.

Bottom line: Most of the city’s automatic meters don’t work — either because they are completely broken or fail to transmit reliable electronic data on water usage, according to a report by the Avanti Company, which has consulted Opa-locka’s government on its utility system over the past decade. That failure has forced the city to provide questionable estimates of some customers’ water consumption, while manually reading meters for others, leading to erratic and exorbitant bills for thousands of residents and businesses.

Avanti’s report has recommended that the city — placed last June under state oversight because of a financial emergency — spend up to $2.1 million on new automatic water meters to bring Opa-locka’s system up to industry standards. The city, which barely has enough money to pay its employees, would have to borrow those funds to replace more than half of the inoperable meters, some 3,000.

But that’s not all: The city also needs to invest a projected $57 million on improvements to the decaying infrastructure of its water, sewer and storm drain systems, according to an assessment by Merrett Stierheim, a former Miami-Dade County manager who has advised the state board overseeing Opa-locka’s finances. He called the city’s utility systems “critically deficient” in a scathing final report.

Outraged by what they see as Opa-locka’s failure to fix the long-standing problems, homeowners filed a class-action lawsuit on Friday, demanding millions of dollars in refunds on their water bills and customer deposits. Last year, the Miami Herald uncovered that Opa-locka officials not only gave preferential treatment to some water users, but also raided $1.7 million in customer deposits in 2014 to balance the city’s deficit-ridden budget. The individual deposits ranged from $170 for homeowners to thousands of dollars for business owners.

George Suarez and his wife, Tania, who bought a home for their family in Opa-locka in 2015, say the city’s leaders are always performing a “song and dance” while telling “bald-faced lies” about local services. Opa-locka residential and commercial property owners pay some of the highest tax and water rates in Miami-Dade County.

“When my 6-year-old daughter has to ask me if my water is going to be cut off, that’s embarrassing,” said Suarez, a catering chef, who has seen his water bills fluctuate wildly since last summer, from an average of $50 to $1,200, then back to $50. “They still want me to pay these ridiculously high bills that make no sense. I’m not going away without a fight.”

The Suarezes, parents of two children, are among nine class representatives in the class action, filed in Miami-Dade Circuit Court. The suit asserts breach of contract and civil theft by Opa-locka’s government.

When my 6-year-old daughter has to ask me if my water is going to be cut off, that’s embarrassing. George Suarez, catering chef

“The city of Opa-locka has trampled on the fundamental right of providing water to citizens by condoning a water supply system that is contaminated by inflated rates, overcharges, theft of deposits and corruption,” said their attorney, Michael Pizzi, former mayor of Miami Lakes, who is working on the case with Miami lawyer Ben Kuehne. “The citizens are now fighting back.”

His suit includes many of the questionable practices highlighted in a series of stories in the Miami Herald during the past year that detailed the plundering of the city’s water system by local officials. Among them: a former public works supervisor, Gregory Harris, who pleaded guilty in an ongoing FBI corruption investigation to shaking down customers for cash bribes while threatening to turn off their water. Former City Manager David Chiverton and City Commissioner Luis Santiago pleaded guilty to the same bribery charges, which also included extorting local business owners who needed city licenses.

Also significant, some customers get special treatment because of their political connections: For instance, Mayor Myra Taylor’s family, owners of a private elementary school, Vankara, have not paid nearly $120,000 in overdue water bills dating back several years. Much of her family’s debt for water services was erased from the city’s books, the Herald found.

Mayor Taylor has refused to comment about the matter, though her husband, John Taylor, a minister, once told the Herald that the family intended to pay its debt.

“There are so many people who have been complaining about their water bills for years, but the city commissioners never did anything about it,” said Steve Barrett, a former vice mayor in Opa-locka and a representative in the new class-action case. “Myra Taylor didn’t care because she never had to pay her water bills.”

The mayor’s school wasn’t the only customer to benefit from the city’s largesse. Opa-locka turned its utility department into an operation that let scores of businesses and residents with political connections tap into Opa-locka’s water system while the city was edging toward insolvency. Apartment landlords were allowed to skip payments for tens of thousands in water bills. Business owners opened new accounts without paying off the old ones.

Potentially dozens of water customs were also suspected of tapping into the city’s water supply without being connected to meters, enabling them to avoid billing.

When Stierheim, the former county manager who has assisted several troubled cities in turn-around efforts, became an adviser to the state oversight board in Opa-locka, he recommended last August that some of the top Miami-Dade water and sewer department employees help the city with its billing problems. The county eventually took over the city’s utility billing operation.

Some customers get special treatment because of their political connections: For instance, Mayor Myra Taylor’s family, owners of a private elementary school, Vankara, have not paid nearly $120,000 in overdue water bills dating back several years.

The city buys its water wholesale from Miami-Dade and resells to residents and businesses; the county also treats the city’s sewage. That relationship has been tested severely over the past two years, with Opa-locka running up a debt of $7 million.

Now the city plans to ask county officials to loan Opa-locka an additional $2 million to pay for the new water meters, mainly because state officials said recently they have no intention of loaning any money for that purpose.

City Manager Yvette Harrell, who made a surprising announcement during the past week that she plans to leave her position, said one of the last projects she wants to accomplish is replacing Opa-locka’s broken meters. She said if the county lends the city the money, the meters could be purchased and installed by summer.

“We don’t have the money,” Harrell told the Herald, “so I’m going to ask the county to purchase them for us and add it to our tab.”