Overheating and water coming out of exhaust

On the way to our farm we hit a terrible corregated section of gravel road.
The following day the engine started to overheat and now when we start up it is initially rough and after three minutes settles down. The radiator needed 1.5 liters of water but the reservoir was still full. Then we picked up water dripping from the manifold flange. My first thought was head gasket but there is no water to be seen or felt.

Appreciate your thoughts/views