The board shall from time to time examine the properties within and without said district, and if it finds tentatively that property, including improvements thereon, has been omitted from the existing roll, or conditions have changed so that there are new properties or additional properties receiving benefit and service from the facilities of the district without charge, it shall cause from time to time an additional roll of such property to be filed with it and shall proceed in the same manner as provided in this chapter where the board causes property roll to be filed with it.