Alaska Water Resources Act of 2005 - Directs the Secretary of the Interior, acting through the Commissioner of Reclamation and the Director of the United States Geological Survey, to conduct a study that includes: (1) a survey of accessible water supplies, including aquifers, on the Kenai Peninsula and in the municipality of Anchorage, the Matanuska-Susitna borough, the city of Fairbanks, and the Fairbanks Northstar borough; (2) a survey of water treatment needs and technologies, including desalination, applicable to the water resources of Alaska; and (3) a review of the need for enhancement of the streamflow information collected by the Geological Survey in Alaska relating to critical water needs in areas such as infrastructure risks to state transportation, flood forecasting, resource extraction, and fire management. Directs the Secretary to submit a report to specified congressional committees on study results within two years. Authorizes appropriations.