The city of Poznań encourages small retention: 'The creation of a rainwater retention system is one of the key activities aimed at improving environmental conditions in Poznań. (...) However, the challenges also rest on the residents themselves. That is why we want to encourage Poznań residents from Poznań to collect and manage rainwater, ' said Jacek Jaśkowiak, Mayor of Poznań.

The amount of the subsidy is:
-80% of eligible expenses, but not more than PLN 5,000 for natural and legal persons,
-80% of eligible expenses, but not more than PLN 50,000 for housing associations and housing cooperatives.