Whenever any tolls or charges for the use of water and other charges for services rendered by an irrigation district have been fixed by the board of directors it shall be lawful to make the same payable in advance, and in case such tolls or charges remain unpaid at the time specified in this chapter for levying the annual assessment, the amount due for such tolls and charges may be added to and become a part of the assessment levied upon the land upon which the water for which such toll or charges levied and remain unpaid was used.
NRS 539.685