The correspondence records mounting complaints by the public and elected officials, and growing irritation by state officials over the reluctance to accept their assurances.
The note - part of a cache of emails released Wednesday by Snyder and reviewed by NBC News - was sent on September 25, 2015, as it became clear that thousands of people in the city had been exposed to lead in their drinking water.
Lead exposure can cause learning disabilities and behavioural problems in children. He announced state budget officials had sought an additional $28.5 million in emergency appropriations which was approved by House committee on Wednesday.
The White House said the officials assured Weaver that the federal government would be a "constructive partner" in the city's response and recovery. If this poisoning had been done by some domestic or foreign terrorist organization, I'm sure the punishments for those responsible would have been considerable.
The issues have hit the presidential campaign to replace Obama, with the Democratic primary front-runner Hillary Clinton slamming Snyder and receiving Weaver's endorsement.
The governor said the state and city can not meet all the needs of Flint residents and painted a bleak picture of the city. "Because it doesn't take a scientist to tell us brown water is not good".
In his appeal letter, Snyder called it a "narrow reading" and likened the crisis to a flood, "given that qualities within the water, over a long term, flood and damaged the city's infrastructure in ways that were not immediately or easily detectable".
"You really don't want to think about it; you want to block it out of your mind", she said. "I had people working for me who contributed to that problem". You deserve to know that the buck stops here with me. "We know that, but if we want to start pointing fingers, there's enough blame to go all the way around".
"We saved hundreds of dollars, and all we had to do was poison an entire city with corrosive leaded water", said a caricature of Gov. Rick Snyder in a cartoon drawn by Brian McFadden in "The Strip" that appeared in last Sunday's New York Times. Obama, who visited Detroit on Wednesday but did not go to Flint, said, "I told her that we are going to have her back and all the people of Flint's back as they work their way through this bad tragedy".
The problems began in April 2014 when the state made a decision to switch Flint's water source temporarily to the Flint River as a cost-saving measure until a new supply line to Lake Huron was ready.
Snyder said in his State of the State address Tuesday night that he was asking state lawmakers for $28 million to pay for bottled water, filters, testing, and the treatment of children with high lead levels.
But even outside of Flint, Obama was unable to avoid witnessing another of Michigan's crises in close range: the widespread closure of Detroit schools after teachers staged a "sickout" to protest the lack of funding and substandard conditions. Residents carried jugs of brownish water to meetings.
States can act irresponsibly with wasteful spending, yes.
At points, the water was found to have bacterial contamination, and then disinfectant used to kill the bacteria caused a chemical contamination. As such, there is a continuing effort to provide residents with bottled water and water filters for their homes while a more long-term solution is investigated.
Still, officials seemed slow to respond.
"It's not 'nothing, ' " the memo said, adding that the water was not an imminent "threat to public health". He has apologized to the residents of Flint.
It's unclear if such carve-outs would be supported by Congress; Republican aides say the bipartisan legislation wasn't meant to provide such wide discretion to the executive branch.