Abstract: A mop bucket system includes a liquid-retaining portion and an energy-dissipation device. The liquid-retaining portion is configured to retain liquid. It has a bottom wall portion, a first sidewall portion, a second sidewall portion facing the first sidewall portion, a third sidewall portion, and a fourth sidewall portion facing the third sidewall portion. The liquid-retaining portion permits retained liquid to move in a liquid-movement direction extending from the first sidewall portion toward the second sidewall portion within a higher-momentum region having a width that is approximately 70% of a distance between the third sidewall portion and the fourth sidewall portion. The energy-dissipation device is disposed within the liquid-retaining portion and extends into the higher-momentum region.