A.   Defined In Statute: The board's duties and powers shall be as defined in the state laws.
   B.   Assistance Of Other Departments: The board shall have power to call on any of the other municipal departments for assistance in the performance of its duties, and it shall be the duty of such other departments to render such assistance as may be reasonably required.
   C.   Practical Difficulties Or Unnecessary Hardships: Where there are practical difficulties or unnecessary hardships in the way of carrying out the strict letter of title 13 of this code, the board of adjustment shall have the power, after public notice and hearing in a specific case, to vary or modify any of the regulations or provisions related to the construction, structural changes in equipment or alterations of buildings or structures in harmony with their fundamental purpose and intent, so that the public health, safety and general welfare may be conserved and substantial justice done.
   D.   Granting Or Denial Of Permit: In every case, however, where a permit is either granted or revoked by the board of adjustment, it must be affirmatively shown that an unnecessary hardship or practical difficulty exists, and the records of such board shall clearly indicate in what particular and specific respects an unnecessary hardship or practical difficulty would be created. (1975 Code § 2.16.010)