The catastrophic decision by Flint, Michigan, to switch to a water supply that brought toxic lead into thousands of homes is routinely portrayed as part of a long-term move to a new pipeline intended to save a destitute city millions of dollars each year.

The reality is much more complicated. The Detroit water system, which had supplied Flint for a half-century, fought fiercely until 2013 to keep the city as a customer. It ultimately offered rates that it claimed would cost 20 percent less than the Flint’s share of the $600 million plan to build the pipeline from Lake Huron.

Had Flint officials stuck with Detroit’s water, they would not have had to rely on the Flint River as an interim water source and lead would not have leached from the city’s aging pipes into the taps of some of its 100,000 residents.

“At a minimum, one would have to ask some pretty tough questions about whether it made sense to build new water infrastructure for a mature and declining population,” Eric Scorsone, director of the Center for Local Government, Finance and Policy at Michigan State University, said Tuesday.

The saga, many years in the making, is a classic political and policy dilemma, one that features difficult decisions over short-term versus long-term savings, as well as a community’s desire for control of its water supply. The decision over a project that will cost hundreds of millions of borrowed dollars went all the way to Republican Gov. Rick Snyder’s office.

Snyder, a former accountant and venture capitalist whose Twitter handle is onetoughnerd, took office in 2011 promising to fix the state’s many financial problems by applying the expertise of outsiders who could reinvent the way government works. In Flint, where poverty had deepened after the departure of much of the auto industry, he appointed a series of emergency managers whose authority superseded even that of the elected city council.

Flint officials had long chafed at purchasing water from Detroit, which, they alleged, overcharged them and sometimes raised rates by large amounts in a single year.

In 2010, they established the Karegnondi Water Authority with the city of Lapeer and three counties to build their own 63-mile pipeline from Lake Huron, as well as treatment and other facilities to go with it. One planning report estimated the cost of the project at $600 million, according to a 2009 story in the Flint Journal.

The Bond Buyer, a trade magazine, would later call the plan to finance construction its 2014 “deal of the year” in the Midwest.

But the Detroit Water and Sewer District wasn’t about to lose a major customer – and a revenue source of $22 million, about 6 percent of its total – without a fight. Emails posted Friday by Bill Johnson, who at the time served as a media consultant for the water district, revealed a series of proposals to keep Flint aboard.

The offers culminated with one that Sue McCormick, then head of the water district, contended would save Flint 48 percent immediately and 20 percent over the long haul.

Flint’s City Council was not swayed. It voted 7 to 1 to approve the new pipeline. Mayor Dayne Walling also approved the plan, and emergency manager Ed Kurtz signed off. Four days earlier, Flint had received approval from state Treasurer Andy Dillon to proceed with the pipeline project.

Detroit served notice that it would stop shipping water to Flint, so Flint tapped its river as an interim source until the new pipeline could be completed. But the state neglected to add the chemicals that would have prevented corrosion in the pipes, and thousands of people drank the contaminated water.

Eighteen months later, on Snyder’s orders, the city was forced to acquire a new water supply: Lake Huron water, furnished by Detroit.