Said County Commissioners shall not lay any main as part of any water system to be supplied with water under Sections <cite data-path="25|§25-22">25-22</cite> to <cite data-path="25|§25-30">25-30</cite>, unless said main be of a size sufficient in the opinion of the Roads and Sanitary Engineer of Baltimore County to supply for the following forty years the territory into which said main and extension thereof may be projected. P.L.L., 1927, §909 1938, §1189 1949, §785 1969, §25-24 1922, ch. 289