Common stream restoration methods, such as the addition of riparian vegetation and in-stream habitat, often fail to subsequently restore macroinvertebrate communities. This suggests there are unaddressed limitations to the re-colonization of desired taxa that physical restoration alone doesn’t overcome. To investigate if the sustained presence of a tolerant macroinvertebrate species was a limiting factor in the re-colonization success of Ephemeroptera, Plecoptera and Trichoptera taxa (EPT), I manipulated densities of Potamopyrgus antipodarum in artificial stream mesocosms and in-stream channels, and measured effectiveness of EPT colonization over time. I found that P. antipodarum density had a significant negative effect on final EPT colonization, where higher P. antipodarum densities resulted in lower EPT colonization, suggesting a density-dependant limitation of P. antipodarum on EPT colonization success. Higher P. antipodarum densities strongly prevented EPT colonization in the first 24 hours of a mesocosm experiment, by driving more EPT to drift out of the systems. Yet, from 24-hours the cumulative colonization of EPT over time was consistent across all P. antipodarum starting densities. This consistent colonization, despite a decline in high P. antipodarum densities, suggests that there may have been a persistent legacy effect of previously high P. antipodarum densities. Therefore, reducing P. antipodarum densities in recovering waterways to facilitate EPT colonization could be successful if the reduction of P. antipodarum to a target density consequently weakened these possible legacy effects. Overall, my results highlight that biotic interactions are likely an important limitation to the re-colonization of EPT taxa, and the application of an ecological baseline or density target could be used for future restoration projects to help overcome legacy effects limiting EPT colonization, thus facilitate ecological recovery.