Many people are not aware of the fact, that the Vistula flows into the sea through the ditch, made artificially in 1891-1985, which shortened the river by about 10 km. The ditch, 7.1 km long, 250 to 400 wide and encased with 10 meters high embankments, was made to protect Gdańsk, Elbląg and the Żuławy region from catastrophic floods and it fulfills this role perfectly. The estuary arms of the Vistula: Nogat, Martwa Wisła and Szkarpawa have been secured with locks. The Mewia Łacha nature reserve was established at the Vistula estuary.
