This doesn't make sense at all. High pressure water can be dangerous for sure, but water based energy storage doesn't use high pressure... It's all about pumping the water uphill and then letting the water flow back down through the pump to recover the energy. At worst your house gets flooded because the containment vessel failed.

Worst case with compressed air is a total disintegration of the tank, the room it's in, and the rest of the house along with the occupants.