Depending on the version the character chose, the control water spell raises or lowers water.

Lower Water: This causes water (or similar liquid) to sink away to a minimum depth of 1 inch. The depth can be lowered by up to 2 feet per caster level. The water is lowered within a squarish depression whose sides are up to 10 feet long per caster level. In extremely large and deep bodies of water, such as deep ocean, the spell creates a whirlpool that sweeps ships and similar craft downward, putting them at risk and rendering them unable to leave by normal movement for the duration of the spell. When cast on water elementals and other water-based creatures, this spell acts as a slow spell. The spell has no effect on other creatures.

Raise Water: This causes water (or similar liquid) to rise in height, just as the lower water version causes it to lower. Boats raised in this way slide down the sides of the hump that the spell creates. If the area affected by the spell includes riverbanks, a beach, or other land near the raised water, the water can spill over onto dry land.

For either version, the character may reduce one horizontal dimension by half and double the other horizontal dimension.