But as pressure starts to mount for lawmakers for an extraordinary relief package, local leaders in Texas and federal authorities in Washington are asking the same question: How much money will it cost?
President Donald Trump has already made a $7.9 billion request
to Congress for emergency funding, which the House passed Wednesday. It's just a starting point for total Harvey recovery spending; the White House says it plans to request an additional $6.7 billion soon.
Still, Texas Gov. Greg Abbott said he thinks the state will need "far in excess" of $125 billion in federal relief dollars. Houston Rep. Sheila Jackson Lee called for a record-breaking $150 billion aid package on CNN on Tuesday.
Trump promised last Monday "you're going to see very rapid action from Congress" about approving recovery dollars. "We're going to get your funding," he told Texans.
Here's a dive into past federal hurricane aid and how Congress might react to this storm.
The recent history of federal hurricane recovery aid
Federal hurricane assistance has spiked since Hurricane Katrina, with the federal government shelling out more than $200 billion -- half of which went to the recovery from Katrina and a quarter of which went to Hurricane Sandy relief efforts.
In the half dozen storms that caused at least $1 billion in damages immediately before Hurricane Katrina, the federal government contributed funds to cover only 17% of estimated damages in federal aid, on average. In storms including Katrina and afterward, federal spending averaged 62% of estimated damages, peaking at 72% of Katrina's damages and 80% of Sandy's damages.
The federal government responded to an estimated $160 billion in economic damage from Hurricane Katrina with roughly $114.5 billion in recovery efforts. And after the $70.2 billion in damage from Hurricane Sandy, the federal government spent $56 billion for relief.
Among the other most expensive hurricanes in the last dozen years: The US spent $12.8 billion after Hurricane Ike caused $34.8 billion in damage in 2008; it spent $9 billion after Rita caused $23.7 billion in damage in 2005; it spent $6.4 billion after Wilma caused $24.3 billion in damage in 2005; and it spent $4.5 billion after Irene caused $15 billion in damage in 2011.
But before Katrina hit, the federal government invested less. It spent only $4.1 billion responding to the major $27.1 billion in damage from Ivan in 2004 and only $2.2 billion responding to the $21.1 billion in damage from Charley.
What to expect for Hurricane Harvey recovery money
So how much federal help should Texas expect? Even Congress doesn't know how many dollars it'll dole out at the end of the day, but we can look at past hurricane recovery efforts for some hints.
Estimates of the damage from Harvey are still very fluid; organizations have been revising their damage estimates as Harvey continued to dump rainfall on Texas over recent days.
The lowest current estimates fall in the $40 to $50 billion range, easily making Harvey one of the most expensive hurricanes in American history. Using the 62% threshold from the past decade of hurricane relief, federal recovery money would fall between $25 billion and $32 billion.
The highest estimate from AccuWeather soars up to $190 billion -- more than both Katrina and Sandy combined -- which would put the 62% federal aid benchmark at $118 billion in support.
Methodology and sourcing
Total federal response spending includes dollars from Federal Emergency Management Agency's Disaster Relief Fund and National Flood Insurance Program, HUD's Community Development Block Grants, the Army Corps of Engineers, the Small Business Administration's disaster loans and money from various other federal agencies, as compiled by the Congressional Research Service.
Economic damage numbers in this article come from the National Oceanic and Atmospheric Administration in 2017 dollars. Total federal spending numbers come from the Congressional Research Service in 2015 dollars, which were converted to 2017 dollars using the Bureau of Labor Statistics CPI Inflation Calculator for this story.
This story includes all hurricanes since 2002 that caused at least $1 billion in damage except Hurricane Matthew, which caused $10.3 billion in damage, according to NOAA, but for which figures on federal response spending were not available.