Abstract: A water emitter is provided for drip irrigation systems which can be modified at the irrigation site to accommodate variations in pressure in differing areas in the specific configuration or layout of system used, and the typography of the land to be irrigated. The emitter includes a flexible, collapsible thermoplastic or elastomeric emitter tube, having a plurality of spaced-apart crimps imparted thereto. The crimps serve to close the emitter tube when no water is supplied thereto, and to provide a sinuous path for water supplied to the emitter, thus increasing friction and controlling pressure at each emitter in the system. The length of each emitter and, therefore, the number of crimps can be selected according to the desired pressure at each emitter site along the system. Also included with each emitter is an elongated, relatively rigid protective tube to prevent soil compaction of the emitter in its collapsed non-functioning state.