A nozzle component (20, 120, 220) of a high-pressure waterjet cutting system that includes an end effector assembly configured to receive high-pressure water and generate a high-pressure waterjet for processing a workpiece, the nozzle component (20, 120, 220) comprising: a unitary body (21, 121, 221) having: a waterjet passage (44, 144, 244) extending through the unitary body (21, 121, 221) along an axis, the waterjet passage (44, 144, 244) including an inlet (46, 146, 246) at an upstream end thereof and an outlet (42, 142, 242) at a downstream end thereof; at least one jet alteration passage (50, 150, 255a, 255b) extending through the unitary body (21, 121, 221) and intersecting with the waterjet passage (44, 144, 244) between the inlet (46, 146, 246) and the outlet (42, 142, 242) thereof to enable selective alteration of the waterjet during operation as the waterjet travels through the waterjet passage (44, 144, 244) and is discharged through the outlet (42, 142, 242); characterized by at least one environment control passage (60, 160, 260) extending through the unitary body (21, 121, 221) and having at least a downstream portion aligned relative to the fluid jet passage (44, 144, 244) so that gas passed through the environment control passage (60, 160, 260) during operation is directed to impinge on the workpiece at or adjacent a waterjet impingement location. a unitary body (21, 121, 221) having: a waterjet passage (44, 144, 244) extending through the unitary body (21, 121, 221) along an axis, the waterjet passage (44, 144, 244) including an inlet (46, 146, 246) at an upstream end thereof and an outlet (42, 142, 242) at a downstream end thereof; at least one jet alteration passage (50, 150, 255a, 255b) extending through the unitary body (21, 121, 221) and intersecting with the waterjet passage (44, 144, 244) between the inlet (46, 146, 246) and the outlet (42, 142, 242) thereof to enable selective alteration of the waterjet during operation as the waterjet travels through the waterjet passage (44, 144, 244) and is discharged through the outlet (42, 142, 242); characterized by at least one environment control passage (60, 160, 260) extending through the unitary body (21, 121, 221) and having at least a downstream portion aligned relative to the fluid jet passage (44, 144, 244) so that gas passed through the environment control passage (60, 160, 260) during operation is directed to impinge on the workpiece at or adjacent a waterjet impingement location. a waterjet passage (44, 144, 244) extending through the unitary body (21, 121, 221) along an axis, the waterjet passage (44, 144, 244) including an inlet (46, 146, 246) at an upstream end thereof and an outlet (42, 142, 242) at a downstream end thereof; at least one jet alteration passage (50, 150, 255a, 255b) extending through the unitary body (21, 121, 221) and intersecting with the waterjet passage (44, 144, 244) between the inlet (46, 146, 246) and the outlet (42, 142, 242) thereof to enable selective alteration of the waterjet during operation as the waterjet travels through the waterjet passage (44, 144, 244) and is discharged through the outlet (42, 142, 242); characterized by at least one environment control passage (60, 160, 260) extending through the unitary body (21, 121, 221) and having at least a downstream portion aligned relative to the fluid jet passage (44, 144, 244) so that gas passed through the environment control passage (60, 160, 260) during operation is directed to impinge on the workpiece at or adjacent a waterjet impingement location.