The competition-winning design will join the three banks where the rivers meet near Hurst Green, Lancashire.
Engineered by the Flint & Neill Partnership, each of the structure's three legs will be 43.5m long and will help to connect the Ribble Way - a favourite path for ramblers.
The bridge will be made from fibre-reinforced plastic - a light, advanced polymer composite - and will weigh just 9.5 tonnes.
Because the site is only accessible by foot, the bridge's lightweight construction will allow it to be lifted into place by helicopter. Concrete will be piped into the tripod-arch structure to reinforce it.
Work on site is expected to start later this year.