Fair Treatment of Existing Levees Act of 2011 - Prohibits the Administrator of the Federal Emergency Management Agency (FEMA) from using the assumption that an existing levee or flood control structure does not exist to designate an area as having new flood hazards pursuant to issuance of, or any process to implement changes in, flood insurance maps used under the national flood insurance program under the National Flood Insurance Act of 1968, except in cases where no affected community objects to the Administrator's hazard modeling processes within 90 days of this Act's enactment and provided that prior to implementation of this provision the affected community notifies affected residents that the level of protection provided by such levee or flood control structure is under review.