According to the first variant of the proposed route of a new highway through Prenj, valleys of the Konjička Bijela and the Mostarska Bijela should be heavily affected, where not much of its natural environment would remained. Beautiful karst phenomenons of deep canyons, underground waterfalls and caves in Mostarska Bijela valley will be destroyed, or at least covered by the asphalt, concrete or stone fill from the tunnels.