The document discusses drainage sluices and locks along the Wadden Sea coast. Drainage sluices ensure drainage from rivers into the sea, opening when the sea level is lower and closing to prevent backflow during storms. The lock on Mandø drains water into the sea and closes automatically at high tide. The kammer lock at Ribe River uses two sets of gates to move ships between water levels, and was built in 1912 to allow passage into the Wadden Sea.

1. The general of the Wadden Sea
Drainage sluices built into the sea dikes ensure drainage of water from streams
and rivers to the sea. The rotary valve is open when the sea level is lower than in
the river, but closes when the sea level is higher than in the river. On coasts like
The Wadden Sea with high tide water and large waves during storms, the shutters
must be very strong to withstand the water pressure; it functions as high tide
shutter.

2. The lock on Mandø
 The lock will drain water into the sea from Mandø. The lock semi –
automatic and high tide closes the gates.
 Østerby, out by the lock, is the old fairway into Ribe, and at low tide,
you can see the tidal flats on the mainland side.

3. The kammer lock at the country of the Ribe River into the wadden sea is
one of the few passage locks in the country.
The Sluice, which consists of two sets of ports brings the ships from one
water level to another. The kammer lock was build in 1912

4. Højer old lock
 This was built in 1861. While now the lock is closed and used only as
extra security by floods, previously it was open to the boat with
masts that could sail to højer harbour port. The port was associated
with lock factory and was primarily used as cargo port for fuel,
fertilizers and building materials.