John Smith was one of IWA's early members and was, in the 1950s, a member of The National Trust's Finance & General Purposes Committee. As such, he played a leading part in the National Trust taking over control of the southern Stratford-upon-Avon Canal, and was deputy chairman of The National Trust for many years. He was a member of the IWA Advisory Committee from 1959 and an IWA Vice-President from 1969. He made substantial donations to waterways restorations, including £50,000 to the Kennet & Avon Canal and £558,500 over several years to support restoration of the Lichfield & Hatherton Canals.
Sir John was the first winner of IWA's most prestigious award, the Cyril Styring Trophy, and held many other public offices including membership of the Museums & Galleries Standing Commission.