Abstract: Large diameter pipes or culverts carrying water or other corrosion producing liquids are cathodically protected by securing, spaced-apart, segment-like elements along the bottom inner (invert) surface of the pipe to effect a partial damming of the liquid therein, causing such surface to remain wet during periods in which the input of liquid is substantially decreased or halted. The achievement of such a continuously wet invert surface provides continuous electrolyte conduction, resulting in both (a) enhanced corrosion protection and (b) greater efficiency in use of the protective anodes.