Impoundments refer to the act of confining or holding something, typically water, within a bounded area. The antonyms for this word would be terms that describe the opposite of containment, such as release, discharge, or freedom. Other antonyms could include words like liberation, emancipation, or deliverance, which all suggest a freeing from confinement or restriction. Negations of the word "impoundment" could also include words that describe the lack of boundaries, such as openness, unfettered, or unencumbered. Regardless of the exact antonym used, it is clear that the opposite of impoundment is freedom, release, and the ability to move or exist without restraints.