Keeping Flood Insurance Affordable Act of 2013

Keeping Flood Insurance Affordable Act of 2013 - Prohibits the Administrator of the Federal Emergency Management Agency (FEMA) from: (1) increasing flood insurance risk premium rates to reflect the current risk of flood for certain property located in specified areas subject to a certain mandatory premium adjustment, or (2) reducing such subsidies for any property not insured by the flood insurance program as of July 6, 2012, or any policy that has lapsed in coverage as a result of the policyholder's deliberate choice (Pre-Flood Insurance Rate Map or pre-FIRM properties). Sets forth expiration dates for such prohibitions.

Amends the National Flood Insurance Act of 1968 (NFIA) to prohibit FEMA from providing flood insurance to prospective insureds at rates less than those estimated for any property purchased after the expiration of such six-month period (currently, any property purchased after July 6, 2012).

Prohibits FEMA from reducing flood insurance risk premium rate subsidies for one non-primary residential property of an owner, with an appraised value that does not exceed $1 million.

Applies the same prohibition with respect to business properties, except that any single business may insure only a single property with such risk premium rate subsidies.

Makes such business property coverage available for an aggregate liability of $1 million with respect to any single building, with another $1 million for contents owned by the building owner, and another $1 million for each unit within the building for contents owned by the tenant.

Directs FEMA to: (1) restore during such six-month period specified estimated risk premium rate subsidies for flood insurance for pre-FIRM properties and properties purchased after such six-month period, and (2) submit to certain congressional committees a draft affordability framework addressing the affordability of flood insurance sold under the NFIA.

Prescribes procedures for expedited congressional consideration of legislation on FEMA affordability authorities.

Permits FEMA to enter into an agreement with another federal agency either to: (1) complete the affordability study, or (2) prepare the draft affordability framework.

Directs FEMA submit to certain congressional committees the affordability study and report.

Amends NFIA to authorize FEMA to reimburse homeowners for successful map appeals.

Makes any community that has made adequate progress on the construction (as under current law) or reconstruction (new) of a flood protection system which will afford flood protection for the one-hundred year frequency flood eligible for flood insurance at premium rates not exceeding those which would apply if such flood protection system had been completed.

Revises guidelines governing availability of flood insurance in communities restoring disaccredited flood protection systems to include riverine and coastal levees.

Requires FEMA to: (1) rate a covered structure using the elevation difference between the floodproofed elevation of the covered structure and the adjusted base flood elevation of the covered structure; and (2) designate a Flood Insurance Advocate to advocate for the fair treatment of policy holders under the National Flood Insurance Program and property owners in the mapping of flood hazards, the identification of risks from flood, and the implementation of measures to minimize the risk of flood.