In the last several years, San Francisco has added underground cisterns for a citywide total of 222, many holding up to 75,000 gallons of water ... the city expand the supply with a target ...

These underground reservoirs of steam and hot water can be tapped to generate electricity or to heat and cool buildings directly. 4 min read Geothermal energy has been used for thousands of years ...

Workers are frantically trying to repair water-supply and sewerage systems, but damage to the intricate underground pipe networks has been extensive, particularly on the Noto Peninsula.