A perennial stream or perennial river is a stream or river (channel) that has continuous flow in parts of its stream bed all year round during years of normal rainfall. "Perennial" streams are contrasted with "intermittent" streams which normally cease flowing for weeks or months each year, and with "ephemeral" channels that flow only for hours or days following rainfall.

The Criminal Grand Jury of Los Angeles County attends hearings brought by the District Attorney’s Office . The objective of this jury is to determine, on the basis of evidence presented by the District Attorney’s Office, whether certain persons should be charged with crimes an d required to stand trial in Superior Court. The Criminal Grand Jury is an accusatory body and not a trial jury; therefore, the burden of proof is much lower. Specifically, the Criminal Grand Jury must decide if there is a strong suspicion the individual committed the alleged crime.

The programs and resources developed by the Education Department of the Los Angeles County Museum of Art are designed to extend the museum experience in the fullest possible way to the widest possible audience, both present and future. These programs provide visitors of all ages with the opportunity to expand their experience with works of art in both the museum's permanent collection an d its special exhibitions.

The Los Angeles County Tobacco Control Program (TCP) is part of the Division of Chronic Disease Prevention and Health Promotion in the Department of Health Services. It was established as a result of the tobacco tax initiative of 1988, Proposition 99/AB75, in December of 1989. The goal of TCP is to establish policies, health services, public education, and media conditions that support the reduction of tobacco use in Los Angeles County and the associated disease, disability, and mortality.

Water polo, or water ball, is a team water sport. The playing team consists of six field players and one goalkeeper. The winner of the game is the team that scores the most goals. Game play involves swimming, treading water (using a sort of kicking motion known as "eggbeater kick"), players passing the ball while being defended by opponents, and scoring by throwing the ball into a net defended by a goalie. "Man-up" (or "power play") situations occur frequently. Water polo, therefore, has strong similarities to the land-based game of team handball.