Pollutants originating sources such as combined sewer overflows and wastewater treatment works are known to have a significant detrimental impact on the quality of water resources. Turbulent shear layers have been previously shown to significantly affect mixing in free surface flows, and therefore may facilitate rapid decreases in peak pollution levels. To date, few studies have considered situations where multiple shear layers interact or the associated effects on flow structure and mixing processes. This paper presents an extensive new high resolution laboratory dataset utilising bank arrays of artificial vegetation within free surface flow to form both single and interacting shear layers systems. The data is used to form and test new analytical relationships between vegetation properties and resulting profiles of primary velocity and mixing characteristics. The results demonstrate that interacting shear layers can significantly enhance transverse mixing processes in open channel flow, and expressions based on vegetated characteristics can give a good approximation of experimentally observed velocities and depth averaged solute concentrations.