A liquid dispensing chamber for use with a drainage system for gathering and dispensing liquids to the ground is disclosed, which includes an elongated wall body having a generally arch-shaped cross-sectional configuration with a top wall portion and a pair of side wall portions thereby defining an enlarged enclosure therein, the elongated wall body including a first end portion and a second end portion, at least one of the end portions defining therein an axial opening to allow axial flow of liquids there-through, a plurality of circumferential reinforcing members disposed along the circumference of the elongated wall body for reinforcing structural strength thereof, and at least one side desk member disposed at least a location in the side wall portions of the elongated wall body. The at least one side deck member selectively includes a lateral opening therein for connecting a connection conduct thereto. Liquid drainage systems utilizing the liquid dispensing chambers of the invention is also disclosed.