SAN FRANCISCO (KRON) — The East Bay Municipal Utility District announced Tuesday, following Monday’s 4.0 earthquake in Piedmont, that nine water main lines were broken.

Most have already been repaired, but questions are being asked about what would happen if an even more powerful quake were to strike the Bay Area. KRON4’s Charles Clifford spent the afternoon looking into the potential problems.

Across the Bay Area, there are thousands of miles of water pipes connecting homes, businesses, and schools. These pipes often cross over fault lines, the most dangerous of which are the Hayward, Calaveras and San Andres faults.

And in an earthquake, any one of those lines could potentially fail, including the line inside your home.

When a big quake does hits, repair crews will start by checking the dams, reservoirs and canals that hold the water supply, and then they’ll work their way through the system ending with the pipes that connect to individual buildings.

In case of a big earthquake, experts said to make sure that you have one gallon of water per person per day, for up to three days. and don’t forget your pets.