On the 18th of August 2016 a small glacier flood started from the Grímsfjall volcano caldera lake. This is a tiny glacier flood according to the news, with the glacier on top of the lake only having dropped around 5 meters so far.
This glacier flood is going into Gígjukvísl glacier river, at the moment Iceland Met Office doesn’t think there is any major danger from this glacier flood. The biggest risk at the moment is from volcano gases that have dissolved into the water and get released when the pressure drops of the water. The glacier water is already in Gígukvísl glacier river, no major changes are expected in that river due to how small this glacier flood is.