A method is presented for estimating the performance of a counter/low cooling tower packed with a regular fill. The model utilized takes into account initial nonuniformity of irrigation and the redistribution of water flow during interaction with the structured fill, In this analysis a local, cellular model for the heat and mass transfer has been formulated, and a compulation scheme has been developed. Solutions for the nonuniform model have been compared to established models that employ the assumption of uniform flow across the plan area of the lower. Results show that regions of nonuniform flow persist for some depth into the flow and that performance of the tower can be degraded.