There shall be in the Department a Federal Housing Commissioner, who shall be one of the Assistant Secretaries, who shall head a Federal Housing Administration within the Department, who shall have such duties and powers as may be prescribed by the Secretary, and who shall administer, under the supervision and direction of the Secretary, departmental programs relating to the private mortgage market. The Secretary shall ensure, to the extent practicable, that managers of Federal Housing Administration programs, at each level of the Department, shall be accountable for program operation, risk management, management of cash and other Federal assets, and program financing related to activities over which such managers have responsibility.