Boris Johnson’s administration decided to buy the £218,000 ($370,971) machines in case there are any repeats of the London riots of 2011, which caused millions of pounds worth of damage.
"Contract negotiations have been completed, and the water cannons will be dispatched to London next week," a spokesperson for the German federal police said on Friday.
A final decision on whether to use the cannons will be made by Theresa May, the Home Secretary. The Metropolitan Police have confirmed that they won’t use them until such permission is obtained.
“We stress that these will not be deployed until or unless the home secretary authorizes the use of water cannon in England and Wales,”said the Met in a statement.
Once they arrive in the UK, the machines will need to be fitted out to British specifications, which will take a few weeks, the Guardian reported.
"These are an operational police assets and their movement is subject to security considerations. Before they are ready to be deployed a number of modifications need to be made. These include the fitting of CCTV and adaptations to bring them into line with the standards used in Northern Ireland. This is expected to take a number of weeks," a spokesman for the mayor’s office said.