@MichaelMulvaney this looks like a Terrestrial Amphipod to me aka Lawn Shrimp. Family Arcitalitridae, possibly in Genus Arcitalitrus. Are you able to Suggest and/or Verify it to that taxon (as I don’t have access to those categories). Thanks so much😊
It was a while ago so I can't be sure but I seem to remember them being something like 2-3 cm. I'd expected them to be much smaller and I was certainly suprised to see them in such an urban wetland!