"I don't think any (previous water donations) have been quite this large," said Kelly Belcher, marketing manager for the Food Bank.
Cassie Ringsdorf, a FEMA spokeswoman, said the agency maintains commodity stockpiles at warehouses across the country and makes them available.
"These commodities are available for use, within hours, should an incident occur that requires support from FEMA," Ringsdorf said in an email to The Flint Journal.
"As a part of our normal commodities management process, FEMA periodically offers commodities nearing the end of their shelf-life to eligible non-profits for donation. These donations are not done, 'on-request,' but are a part of our normal strategy to maintain our stockpiles for use in emergencies," the statement said.
A news release from the Food Bank credited Michigan State Police Lt. Billie Jo Roach with having identified the availability of the water from FEMA.
Flint remains in a public health emergency, and officials have said residents should not drink unfiltered tap water because of rising lead levels while the city used the Flint River as its water source from April 2014 until October 2015.
Earlier this month, Virginia Tech professor Marc Edwards said even though the city no longer uses the river as a water source, water remains unsafe to drink unfiltered in some areas of the city.
Roach is the MSP Emergency Management and Homeland Security Division District 3 coordinator.
The Journal could not immediately reach a representative of the MSP Emergency Management and Homeland Security Division for further comment.
FEMA said the Food Bank claimed two truckloads of water and agreed to pay all transportation costs associated with the donation.
Belcher said the United Way of Genesee County paid that expense for the Food Bank.
The Food Bank's partner agencies that will receive the FEMA water include soup kitchens, homeless shelters and food pantries, the organization said in its news release.