Ala. Code § 18-2-14

On making such payment, the applicant is vested with a qualified estate in fee to the acre of land located and circumscribed by the jury, such estate to become absolute on performance of the following conditions: (1) That the dam or mill, gin or factory be commenced within one year and finished within three years from the date of the grant. (2) That whenever the dam or mill, gin or factory is destroyed or materially impaired, the same must be rebuilt or repaired within three years thereafter. But if the owner of such dam is an infant or person of unsound mind, he is allowed the same length of time, after the removal of such disability, to commence, finish, repair or rebuild.