According to an April 29, 2013 article in The Washington Post, the federal government is spending more than previously thought on disaster relief.  The Post article cites a report released by the Center for American Progress, which found that:

the federal government--which means taxpayers--spent $136 billion total from fiscal year 2011 to fiscal year 2013 on disaster relief.  This adds up to an average of nearly $400 per household per year.

In an even more disconcerting portion of the report, the authors revealed that no one in government knew the exact amount that had been spent on disaster relief.  In order to make an estimate, the authors examined the relevant appropriations and supplemental bills that Congress enacted between fiscal year 2011 and fiscal year 2013.  When examining the years prior to 2011, the problem is becomes even more severe.  From the Center for American Progress Report:

As part of the Budget Control Act of 2011, the Office of Management and Budget was required to report to Congress on 'disaster relief spending … over the previous 10 years.' It determined that, 'The average funding provided for disaster relief over the previous 10 years (excluding the highest and lowest years) is $11.5 billion for fiscal year 2011.' OMB estimated that actual disaster-relief spending in 2011 was $2.5 billion. We estimate that the federal government spent $21 billion on disaster relief and recovery in fiscal year 2011.

As Citizens Against Government Waste has stated in the past, Congress should improve the transparency of its disaster spending by creating some sort of rainy day fund that would contain money for unpredictable disasters.  According to CAGW's Luke Gelber:

Ballparking an emergency budget during the appropriations process would lend transparency, stability, and quality to spending bills that are intended to help people in need.  It would prevent lawmakers from tacking frivolous projects onto emergency relief bills, thus removing the incentive to vote against otherwise well-intentioned legislation and preventing time-sensitive relief from being bogged down in Congress.

Creating a rainy day fund would also greatly hamper the ability of lawmakers to insert pork-barrel projects into emergency relief funding.  By subjecting this funding to the normal budgeting process, Congress will be able to better direct disaster relief funding to those most in need, and taxpayers will be able to rest assured that their money is not being spent on extraneous, wasteful projects.