Practical experience and common sense fitted Petrie for laying the sound foundations of municipal administration in Brisbane and for guiding the council in providing public works and services. Closely associated with the Enoggera Dam while it was planned by the council, he later saw it constructed as a member of the Board of Water Works; as its chairman in 1875 he was a leader in implementing the Gold Creek Dam and planning of the Mount Crosby Weir. After serving as mayor, he had difficulty in 'playing second fiddle' and was prone to indulge in such manoeuvres as walking out of council meetings.