100. Every water utility, in accordance with Rule 4.115(2), shall prepare or cause to be prepared and shall keep on file permanent and adequate records in the form of maps or clearly descriptive tabular statements or both showing the size, kind and location of all of its underground mains or other hidden construction and shall define locations of all valves and shut-off cocks. For all new construction work done, the records shall show date of construction by year and month.