The Robert T. Stafford Disaster Relief and Emergency Assistance Act, 42 U.S.C §§ 5121-5207 (the Stafford Act) states that requests for a Presidential disaster declaration be made from the governor of the affected state.
If it is apparent that a Presidential disaster declaration may be necessary to help in the recovery of a certain impacted area, the state contacts the FEMA regional office to do a preliminary damage assessment (PDA). The assessment includes the extent of the disaster, its impact on individuals and public facilities, and the types of federal assistance that may be needed. Once the PDA is complete and the State determines that the damage exceeds its resources, the Governor can submit a declaration request through the FEMA Regional Office.
Usually, the PDA is completed prior to the Governor's request for a major disaster declaration. However, when a severe or catastrophic event occurs, the Governor can submit the request prior to the completion of the PDA. The PDA has information about the nature and the number of resources that the State commits to the disaster, an estimate of the amount of severity of the damage, and an estimate of the type and amount of assistance needed under the Stafford Act.