Hi looks like Epilobium sp. (willowherb), not sure of the species though, maybe great willowherb? hoary willowherb?. I'm sure someone here will be able to give a specific i.d. for you
I can see it must be wet there, as there is an alder tree growing next to it.
yes it's one of the Epilobium's mentioned - these are distinct in the 4-lobed stigma and the hairier leaves. I suspect that it's Great Willowherb (E. hirsutum) which has bigger brighter flowers than the Hoary willowherb (E. parviflorum) ....petals >10mm rather than 5-9mm.
It is Epilobium hirsutum. It not only have larger flowers than parviflorum, but also much wider petals that are deeper coloured.
E. parviflorum http://linnaeus.nrm.se/flora/di/onagra/epilo/epilpar2.jpg