Why did the Imperial Canal break threaten the Imperial Valley in 1905?

In 1905, floodwaters caused a breach in the diversion controls of the Imperial Canal, located south of the California-Mexico border. This failure allowed the Colorado River to rush into the Salton Sink, creating the Salton Sea.1

The break posed a severe threat to the Imperial Valley because the uncontrolled flow of water risked inundating the region's agriculturally rich lands. Additionally, the flooding threatened to permanently block a major railroad route. To mitigate this imminent danger, the railroad company repaired the breach and subsequently constructed a system of protective levees by 1907.1