This disclosure relates to a liquid delivery apparatus comprising: a base assembly (7)； a vessel (5) into which liquid may be introduced via an inlet to at least partially fill the vessel (5) and to pressurise the liquid in the vessel (5)； a nozzle (11) comprising a discharge tube (17) and a nozzle outlet (17'), wherein the nozzle (11) is rotatable with respect to the base assembly (7), and the nozzle outlet (17') is provided at a distal end of the nozzle (11) via which said liquid may be discharged from the vessel (5) under the pressure of the liquid in the vessel (5)； and a valve (9) between the vessel (5) and the nozzle (11) to control passage of liquid from the vessel (5) to the nozzle outlet (17')； wherein the valve (9) and nozzle discharge tube (17) are arranged so that they are substantially in line. A drive system (16) for a liquid delivery apparatus is also disclosed, wherein the drive system (16) is configured to drive rotation of the nozzle (11) with respect to the base assembly (7). The drive system (16) may be configured to propel the liquid delivery apparatus along the ground.
