Before revision: Culverts and pipelines can actually help to block flow and lead to the development of more extensive aufeis.Williams and Smith Aufeis can present an extreme danger to recreational boaters even during summer months, who can find themselves trapped between walls of ice or pulled under aufeis by the current of the river.
After revision: Aufeis can present an extreme danger to recreational boaters even during summer months, who can find themselves trapped between walls of ice or pulled under aufeis by the current of the river.