An irrigation sprinkler is provided having a housing and a riser assembly for the distribution of irrigation water that includes a wiper seal to prevent bypass flow. The sprinkler includes a first flow path that delivers water to a nozzle for irrigation and a second flow path that delivers water to a cavity between the riser assembly and the housing. The water in the cavity is substantially prevented from exiting the cavity because of an annular wiper blade and a secondary sealing blade that substantially contact the riser assembly through the riser assembly's reciprocal movement between retracted and elevated positions. The water in the cavity is additionally prevented from exiting the cavity due to a primary sealing blade that substantially contacts the riser assembly for a limited period of time when the riser assembly is in the elevated position. By limiting the period of time in which the primary sealing blade contacts the riser assembly, the primary sealing blade experiences less friction and seal degradation during reciprocation.