There is no zakaah on money that is being held as compensation for taking land

You do not have to pay zakaah on this money until you take
possession of it; when you take possession of it you should count one
(hijri) year from the day you took possession of it, then pay zakaah on it
after one year. 

Shaykh Ibn Baaz (may Allaah have mercy on him) was asked a
similar question, and he replied: If property has been seized and its value
estimated, but the owner has not been able to take possession of it due to
reasons beyond his control, no zakaah is due on it until he takes possession
of its price and a full year has passed. End quote. 

Majmoo’ Fataawa Ibn Baaz
(14/41) 

And Allaah knows best.