William Thwaites (1853–1907) was a civil engineer working in Melbourne, Australia in the late nineteenth and early twentieth centuries.

This, as part of a total of £330 in scholarships and exhibition prizes, helped greatly to fund his education, otherwise unobtainable through his family's limited means.

[2] Under an agreement between Melbourne University and the Victorian government, Thwaites undertook 12 months experience under supervision of an engineer, Arthur Wells, as pupil draftsman in the railway department.

[4] Following this he moved on to the Port Wakefield and Kadina railway, although he was subsequently without work during 1878 and returned to Melbourne, where he joined the Harbour Branch of the Victorian Public Works Department (PWD) in 1879 to survey the Portland Harbour, Gippsland Lakes entrance and Sale navigation canal, as part of preparatory plans for their development under John Coode's designs.

However, a major failure in this period was the cracking of the new water main over Merri Creek on the Yan Yean supply, which was shown by WC Kernot to have been caused by errors in Thwaites' and Davidson's design.

[8] Thwaites' greatest achievement was in the design and supervision of the construction of Melbourne's underground sewerage scheme, which was at the time the largest civil engineering project in the history of Victoria.

[3] The large main sewers proposed by Mansergh would not have created sufficient velocity to scour the solids, particularly in the early stages before many properties were connected, and so Thwaites believed they would require manual cleaning.