Rivers

A short history of the Los Angeles River:

The Los Angeles River has changed course many times over the last 150 years. First it was the burgeoning city's main source of water. In the late 1930s it was transformed into a flood control channel. In 2007, it was named an amenity of the city's master plan.

And soon, it will be changing course again. The Army Corps of Engineers is now supporting a plan to return it to something like its natural state. Of course, its natural state was a seasonally changing (if continuously running) flow of water that rarely had enough power to carve more than a shallow channel. This meant it also had a tendency to jump its banks, sometimes creating brand new channels miles from the old. After the Flood of 1938, the river channel was covered in concrete along most of its length - by the Army Corps of Engineers.

And all this is to note that the last major change was also during the Crisis - starting immediately after that flood,  nine years after the Crash, a few years before Pearl Harbor. While it was the worst flood ever in Los Angeles, it was not the first time the river had gotten out of control. There were significant floods in 1862, 1889, and 1914. Bonds for flood control were proposed to the electorate in 1917 and 1926 -  the former barely successful --  a margin of 51 votes out of almost seventy thousand cast -- the latter failing. Whereas in 1938, significant flood control projects were completed before the year was out, with more completed over the next few years. One of the largest projects, the Sepulveda Dam, was completed in December 1941.

It's as if there are points in time when a collective decision is made to take care of problems that have been allowed to continue for too long. And those points occur every 80-90 years.

(Thanks to Gumprecht's The Los Angeles River for additional background on the river, its flood history, and how the flood control plan was implemented.)