The decision to switch the city of Flint’s drinking water source to the Flint River was pegged as a cost-cutting maneuver aimed at saving $5m over a two-year period. But almost two years and a massive lead contamination crisis later, that move and subsequent decisions not to treat the water supply already carry a financial price tag of $45m and climbing.

Since early October, when Michigan governor Rick Snyder first conceded that lead contamination in the Rust Belt community of 100,000 was far more serious than he initially understood, state and federal agencies have pledged at least $45m to address the ongoing crisis, including:

In October, Snyder announced a $12m plan to transfer Flint back to the city of Detroit’s water system. The state covered half the cost, while Flint kicked in $2m and the Charles Stewart Mott Foundation contributed $4m.

Last week, Barack Obama approved Snyder’s request to declare a federal emergency in Flint, providing $5m in financial assistance through the Federal Emergency Management Agency for additional water, water filters and water test kits.

On Tuesday, during his state of the state address, Snyder promised a $28m aid package for the city of Flint that includes $17.2m for bottled water and filters; $3m for city utilities for loss of revenue; and nearly $4m for behavioral health care for children with elevated blood lead levels. The plan has since been approved by the Michigan house of representatives, and is pending in the state senate.

That number is expected to climb, and doesn’t include the cost of infrastructure improvements Snyder is now seeking. Snyder has said his upcoming budget proposal will likely include a request for additional funds. But with estimates suggesting the price tag to overhaul Flint’s water infrastructure is between $750m and $1.5bn, officials have said the assistance isn’t nearly enough.

At the US conference of mayors in Washington DC this week, Flint mayor Karen Weaver said the city “needs to be made a priority” by the state and federal government.

“This is bigger than the city can handle financially … so we need some federal assistance,” Weaver said. What [Snyder] talked about is a very good start, but we deserve more resources, and more finances as a result of this.”

For decades, the city relied on the Detroit water system to provide water. But in the face of financial calamity, in early 2014, a state-appointed emergency manager running the city green-lighted the switch to a local source.

By last February, the costs to address water quality issues in the city started to accumulate. As tensions in Flint started to grow over the city’s water quality, the state government provided a $2m grant for “water system enhancements” in Flint.

It was also confirmed this week that Michigan will receive $80m in funds from the federal government for water infrastructure improvements. The state will decide how much is appropriate to Flint, but Snyder previously asked the Federal Emergency Management Agency to provide upwards of $54m for infrastructure upgrades as part of Snyder’s $96m request for Obama to declare Flint a disaster zone.

The governor has since appealed the decision, which said Flint’s crisis didn’t meet the legal definition of a “major disaster”, as it was not the result of a natural catastrophe.

The least quantifiable financial costs likely to face the city will be those of monitoring and treating the current and future health problems of Flint residents from their lead contamination.

It could be months, if ever, before it’s determined how many residents have experienced elevated blood lead levels. State officials have said all children in the city should be treated as if they were exposed.