Dam Rehabilitation and Repair Act of 2015

Amends the National Dam Safety Program Act to require the Federal Emergency Management Agency (FEMA) to establish a program to provide grant assistance to states for use in rehabilitating publicly-owned dams that fail to meet minimum safety standards of the state or an Indian tribe and pose an unacceptable risk to the public (deficient dams).

Sets forth provisions regarding procedures for grant awards and fund allocation. Requires FEMA to: (1) require a state to provide an assurance that the owner of the dam to be rehabilitated has developed and will carry out a maintenance plan during the expected life of the dam, (2) require a recipient of a grant under this Act to comply with requirements applicable to contributions of federal funds under the Robert T. Stafford Disaster Relief and Emergency Assistance Act, and (3) develop a risk-based priority system for identifying deficient dams for which such grants may be made. Limits the federal share of rehabilitation costs to 75%.

Prohibits grant funds from being used to: (1) rehabilitate a federal dam, (2) perform routine operation or maintenance, (3) modify a dam to produce hydroelectric power, (4) increase water supply storage capacity, or (5) make any other modification that does not also improve dam safety.

Conditions the receipt of grants by a state upon the state following specified requirements applicable to contracts for architectural and engineering services when entering into contracts for services relating to dam rehabilitation. Provides that such contracts shall not be considered to confer a proprietary interest upon the United States.

Prohibits funds from being obligated for a project under this Act unless the steel, iron, and manufactured goods used for the project are produced in the United States. Authorizes waivers.