FLINT, MI -- The problems started after the push of a button, a toast with Flint River water and a budget forecast of saving $5 million that had to be tempting for a city in the midst of a financial emergency.

It was only nine months ago that Flint officials turned off the flow of already-treated Lake Huron water from the city of Detroit and started treating their own raw water from the Flint River instead, calculating that the switch could save roughly $5 million in less than two years.

But what started as a cost-cutting move for a city in financial turmoil has turned into a growing demonstration of public unrest, as customers are rebelling against the most troubled and expensive public water system in Genesee County.

Well-known environmental activist Erin Brockovich has weighed in on the saga, and now some City Council members say they're ready to abandon the use of river water -- regardless of the short-term savings tied to using it.

Even Mayor Dayne Walling, who pushed the ceremonial button that changed Flint's water source in late April, said that in hindsight, he now believes the challenges of treating river water were "underestimated" by those who made the decision.

He said this week that the city is paying the price for not having been prepared to take on the job of turning river water into drinking water.

"The outside assistance -- (contracting with a water quality consultant) with experience in river water management -- should have been (done) months ago in retrospect," Walling said. "It should have been part of the plan from the beginning."

The most vocal outcry against Flint water problems began earlier this month, when the city told customers it was in violation of the federal Safe Drinking Water Act because of the high level of total trihalomethanes (TTHM), a byproduct of the large amount of chlorine needed to kill off bacteria in the river water.

The notice -- sent to customers throughout the city -- has prompted street protests, meetings, bottled water drives and talk of a class action lawsuit. Some residents have presented city officials at public meetings with jugs of yellow, cloudy water from their faucets, saying the water is causing health issues.

"A lot of people are moving away. They are fed up, and the ones that can afford it will leave the city," said Florlisa Fowler, a Flint resident who started a Facebook page -- Flint Water Class Action Group, which now has more than 1,300 members.

"This should never have been allowed to happen," Fowler said. "I feel like they knew what was going to happen."

Initially, city documents show Flint officials planned to use that $5 million short-term savings to make upgrades at the Flint Water Treatment Plant and to start something that had been ignored for decades -- replacing some aging water transmission pipes and valves before connecting to the Karegnondi Water Authority pipeline sometime in 2016.

Flint's capital improvement plan estimates $50 million in water infrastructure spending is needed during the next six years -- money the city doesn't have.

Documents posted recently on Flint's Web site say the city believed it was prepared to deal with the challenges of treating river water because of its licensed staff, the experience of its contract engineering company, help from the state Department of Environmental Quality, and the past investments in equipment at the city's treatment plant.

At the time of the switch, city and state officials assured residents they wouldn't notice a difference in the smell or taste of tap water once the river was tapped.

Instead, citizens began complaining almost immediately about the smell, color and taste of river water, and within four months, boil water advisories were issued for parts of the city after tests showed bacteria, including E.coli, in the water system. The city cleared up the bacteria problem by upping the level of disinfectant and implementing other changes.

The city was forced to open fire hydrants in the summer and fall to keep water from growing stagnant in a system that's twice as big as it should be for the number of customers using it.

Then in October, the city was dealt another blow when General Motors said it would no longer use Flint water in one of its plants here because high chloride levels were causing corrosion in engine parts.

State and local officials have said Flint's water is safe to drink for most people, but the notices mailed to customers about TTHM levels this year caused worries.

The notices warn those with "a severely compromised immune system, (who) have an infant or are elderly" that they "may be at increased risk and should seek advice about drinking water from your health care provider."

The same notice says the disinfection byproduct in city water could -- over many years -- cause liver, kidney or central nervous system problems and an increased risk of cancer.

At protests, public meetings and on social media, some residents have blamed the water on ailments ranging from rashes to cancer. But the county Health Department's chief officer has said he drinks it and said customers don't have much to be worried about -- partly because people won't be drinking large amounts of the water for decades.

Earlier this week, Dr. Joan Rose of Michigan State University, told residents that TTHM isn't the cause of cloudy, discolored water she saw at a town hall meeting but is more likely related to Flint's old transmission pipes.

Skin problems could be related to the hardness of Flint's treated water, Rose said.

Amid the city's water issues, Flint's colleges told employees and students they would be independently testing the water to try to allay concerns. Flint's hospitals also have made adjustments ranging from offering bottled water to specially treating equipment that requires softer water.

Flint resident Cindy Marshall, who attended a protest Jan. 21, said all she wants is "clean, safe water."

"I am paying over $130 in water bills, plus $150 in store-bought water," she said. "I won't let my dog drink it or my fish swim in it.

"I wish Flint officials would give us our Detroit water back," she added.

The city's water problems have caught the attention of Brockovich, an environmental activist who says officials from Flint to Washington, D.C., need to fix the water and stop making excuses.

"Now is not the time for the blame game...Detroit has failed and Flint jumped ship. So much for local control... everyone is responsible from the top down," she said on her Facebook page.

MLive-The Flint Journal could not reach emergency manager Jerry Ambrose or Department of Public Works Director Howard Croft for comment on whether they believe the savings tied to using river water has been worth the resulting fallout.

Walling said the decision to use river water last year was made by emergency manager Darnell Earley, but the mayor said he was involved in the decision for the city to join the Karegnondi Water Authority in 2013.

"The governor and the (state) treasurer to their credit recognized it was important for the city's elected representatives to be included in the decision about the long-term source (of water) because we would be living with it," he said. "But once the decision was made in April 2013, it become an operational issue ... and I wasn't directly involved."

"I wasn't directly involved in the city's (decision) to use the Flint River as a source," he said. "It's now clear that the challenge was underestimated."

Walling blamed the Detroit Water and Sewerage Department for terminating Flint's contract to purchase Lake Huron water while the KWA pipeline is under construction.

"I do think it bears repeating that it was DWSD that terminated the contract with the city of Flint," he said. "DWSD put the city of Flint in a difficult position when they terminated that contract we had for decades and decades ... My goal had always been to have a cooperative relationship with DWSD but every opportunity that was looked at ended with a barrier."

A return to purchasing water from Detroit while the KWA project is completed is something that City Council President Josh Freeman said he's willing to consider, but Earley and Ambrose have said it's too expensive of an option and said a short-term deal might not even be possible.

DWSD made an offer for a "long-term" deal for water in a Jan. 12 letter to Flint's mayor and emergency manager, but it wasn't immediately clear whether the arrangement offered by Detroit was also available for a relatively short-term period.

Flint officials claim the use of Detroit water this year alone would cost Flint an additional $12 million.

"I'm open to explore going back to Detroit, but it's not as easy as going and switching a switch," Freeman said. "I drink the water. I shower in it, but I get the smell (issues). I taste the difference."

The combination of discoloration, strong smells from water and boil water and Safe Drinking Water notices from the city have combined to create both legitimate problems and a crisis in confidence, Freeman and Walling said.

GM retiree Dale Radford said he doesn't see the difference in his water with the naked eye but he's recently started buying his drinking water in 5-gallon jugs.

"I know they say it's safe to drink but I think everybody is kind of worried about it," Radford said. "I don't think the water tastes the same. I think the coffee in the morning tastes different.

"I think they should have worked it so we kept the same water, but after all is said and done, we're stuck with what we've got," Radford said.

Staff writer Kurt Nagl contributed to this report.