The seasonal deposit in Clash of Clans it is a kind of warehouse where you store the resources you earn during a season, unlike the normal elixir and gold warehouses. Here we tell you a little more about what it is.
Where the resources of the season deposit go when the season is over
The resources at the end of the month go to your regular stores, so you don't have to worry. The problem is that you don't have enough space in your seasonal depot to hold all the resources you earn so they will be lost unless you buy the gold pass which will allow you to increase capacity.
It also happens that if your warehouses were filled with part of the contents of the deposit, and you have nowhere to put the rest, then as part of the benefits of the gold pass, you can convert your resources into gems so you don't lose them.