Notwithstanding Section 60327, each producer shall pay the Water Replenishment District of Southern California a replenishment assessment, imposed pursuant to this act, in monthly installments due on the last day for filing the groundwater production statement required by Section 60326.1. The assessment amount shall be computed by multiplying the facility’s stated groundwater production, measured in acre-feet, by the replenishment assessment rate imposed by the district board for the fiscal year in which the production occurs.