1. A computer-implemented method for simulating water, comprising: representing a three-dimensional model of a fluid volume as a two-dimensional grid of columns, wherein each column within the two-dimensional grid includes a single tall cell and one or more regular cubic cells, wherein each column comprises a constant number of the regular cubic cells; computing, via a processor, one or more velocities of a fluid velocity field; for each single tall cell included in the two-dimensional grid of columns, storing, in the single tall cell, only one velocity component of the one or more computed velocities for each neighboring tall cell directly adjacent to the single tall cell in order to maintain a constant data size for the one or more computed velocities; and for each column in the two-dimensional grid of columns, updating a height of the single tall cell associated with the column based on one or more velocities stored in the single tall cell.