Idaho Anadromous Fish Habitat Restoration Act - Authorizes the Secretary of the Interior acting through the Commissioner of Reclamation to undertake appraisal-level investigations of the water and related resources of the following river drainages lying wholly or partially within the State of Idaho: (1) the Lemhi River basin; (2) the Pahsimeroi River basin; (3) the Potlatch River basin; and (4) the Palouse River basin. Declares that the objective of each investigation shall be to: (1) identify where environmental improvements could be made or water storage facilities constructed within each basin to restore or improve the habitat of anadromous species of fish; and (2) identify secondary opportunities within each basin, including the improvement of agriculture, municipal, and industrial water supplies. Requires the Secretary to submit a report of the findings and recommendations from each investigation to the appropriate Congressional committees on or before September 30, 1983.