An integrated combustor nozzle for a turbomachine, comprising: a combustion liner extending along a radial direction between an inner liner segment and an outer liner segment, the combustion liner including a forward end portion, an aft end portion, a first side wall, and a second side wall, the aft end portion of the combustion liner defining a turbine nozzle, the combustion liner defining a cavity forward of the turbine nozzle, wherein the cavity extends between the first side wall and the second side wall; an impingement cooling apparatus positioned within the cavity, the impingement cooling apparatus comprising: a flange (310, 311); and a plurality of impingement members configured to direct coolant to impinge upon at least one of the first side wall and the second side wall, wherein each impingement member of the plurality of impingement members extends from a respective inlet defined within the flange (310, 311) to a respective closed end, and wherein a plurality of impingement apertures are defined on each impingement member of the plurality of impingement members, wherein the plurality of impingement members comprises a first row of impingement members disposed proximate the first side wall and a second row of impingement members disposed proximate the second side wall, and wherein the first row of impingement members and the second row of impingement members diverge away from each other from an aft end to a forward end of impingement cooling apparatus. a combustion liner extending along a radial direction between an inner liner segment and an outer liner segment, the combustion liner including a forward end portion, an aft end portion, a first side wall, and a second side wall, the aft end portion of the combustion liner defining a turbine nozzle, the combustion liner defining a cavity forward of the turbine nozzle, wherein the cavity extends between the first side wall and the second side wall; an impingement cooling apparatus positioned within the cavity, the impingement cooling apparatus comprising: a flange (310, 311); and a plurality of impingement members configured to direct coolant to impinge upon at least one of the first side wall and the second side wall, wherein each impingement member of the plurality of impingement members extends from a respective inlet defined within the flange (310, 311) to a respective closed end, and wherein a plurality of impingement apertures are defined on each impingement member of the plurality of impingement members, wherein the plurality of impingement members comprises a first row of impingement members disposed proximate the first side wall and a second row of impingement members disposed proximate the second side wall, and wherein the first row of impingement members and the second row of impingement members diverge away from each other from an aft end to a forward end of impingement cooling apparatus. a flange (310, 311); and a plurality of impingement members configured to direct coolant to impinge upon at least one of the first side wall and the second side wall, wherein each impingement member of the plurality of impingement members extends from a respective inlet defined within the flange (310, 311) to a respective closed end, and wherein a plurality of impingement apertures are defined on each impingement member of the plurality of impingement members, wherein the plurality of impingement members comprises a first row of impingement members disposed proximate the first side wall and a second row of impingement members disposed proximate the second side wall, and wherein the first row of impingement members and the second row of impingement members diverge away from each other from an aft end to a forward end of impingement cooling apparatus.