Amends the Robert T. Stafford Disaster Relief and Emergency Assistance Act to: (1) increase from 75 % to 90% the amount the President may contribute toward the cost of cost-effective hazard mitigation measures which substantially reduce the risk of future damage, hardship, loss, or suffering in any area affected by a major disaster; and (2) double from 7.5% to 15% of the estimated aggregate amount of federal disaster relief grants to be made with respect to a major disaster the limit on the total amount of contributions the President may make for cost-effective hazard mitigation measures in the disaster area.