"The principles of disaster management assume a leadership role by the local and state governments with the federal government providing coordinated supplemental resources and assistance. A declaration of a major disaster or emergency must, in almost all cases, be requested by the governor, who at that point has declared that the situation is beyond the capacity of the state to respond. The governor also determines which parts of the state they will request assistance for and suggests the types of assistance programs that may be needed. The President considers the governor's request, in consultation with officials of the Federal Emergency Management Agency (FEMA), within the Department of Homeland Security (DHS), and makes the initial decisions on the areas to be included as well as the programs that are implemented. The immediate response to a disaster is guided by the National Response Framework (NRF), which details roles and responsibilities at various levels of government, along with cooperation from the private and non-profit sectors, for differing incidents and support functions. […] While the disaster response and recovery process is fundamentally a relationship between the federal government and the requesting state government, there are roles for congressional offices to play in providing information to the federal/state response and recovery teams in their respective states and districts. Congressional offices also serve as a valuable source of accurate and timely information to their constituents."
CRS Report for Congress, R41981