As firefighters scrambled to extinguish the wildfires consuming neighborhoods across Los Angeles County this month, they often found that the hydrants outside the burning houses were not much help. It was hardly the first time in recent years that a wildfire had encroached on an American neighborhood, and hardly the first time that hydrants were unable to make a serious dent in stopping an unfolding disaster. In Colorado, Hawaii and other parts of California, hydrants have provided minimal relief as home after home has burned.  A combination of extreme conditions, poor planning and delayed evacuations contributed to the widespread devastation around Los Angeles. There were also specific limitations on the region’s network of fire hydrants, including a large reservoir that was offline for maintenance. But in most cases, experts say, a working hydrant system would be inadequate for fighting a large-scale wildfire.