While modern technology ensures safety standards are maintained at the 80,000 dams across the US, extreme weather and maintenance issues have resulted in some serious dam failures over the past four decades. On Sunday, an urgent evacuation order was issued for 200,000 people living in northern California amid fears of an imminent collapse of the nearby Oroville Dam spillway. Oroville, America’s tallest dam, remains intact but the emergency spillway, which helps prevent water from overflowing when levels are high, is eroding. Heavy rainfall has filled the dam to the verge of overflow, posing a huge potential risk to downstream communities....