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Aug 23 2011

The Next New Orleans? (Part 1)

“Nature in California… is a smiling killer that can turn on you at any time.” – Carl Nolte (San Francisco Journalist quoted in “Battling the Inland Sea” by Robert Kelley)

Where is the next New Orleans, the next potential flooding disaster? Most people say that it is Sacramento, California. Between hydrographic surveys, mapping, hydraulic modeling, levee inspections, bank protection design, and gradient restoration facility design, Dusty, my co-author of this blog, and I have over 20 years combined experience in the Central Valley. The Central Valley is infamous for its flat and expansive inland extents. It’s also infamous for the elaborate system of levees that protect its population.

The Inland Sea

When settlers first came to this area in the 1800s, they called it “The Inland Sea.” Why did they give it this name? Let’s just say they experienced enough to know the area tends to fill up like a bathtub during a flood event! We’ll discuss this in more detail as we look at the history of the valley. The northern part of the valley is the Sacramento River basin while to the south is the San Joaquin River basin. The total population of the valley is roughly 6.5 million people.

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Below is a picture of the Sacramento Valley, the northern part of the system where about 2.5 million people live within a very intricate and complex system of levees (the pink lines). The larger body of water to the far right is Lake Tahoe.

Central Valley Map - Sacramento

The First Settlers and Flooding

When Sutter first settled in this area in the mid 1800s, he wisely did not establish himself right along the Sacramento or American rivers but took the high ground a few miles away. However, this is not the approach the future settlements took! In 1848, the gold rush took off and the City of Sacramento was established. Only 2 years later, the first major flood hit Sacramento. Had they actually talked to any of the local Native Americans, they would have been told about the flooding but few knew or talked to any. You would think they would learn the lesson and re-establish on higher ground but that’s not what happened…

As townspeople recovered from the inundation and looked about them at the waste of waters, they were not appalled and humbled by their experience but instead confident that the problem could be promptly mastered. – Robert Kelley, “Battling the Inland Sea”

You have to remember that these folks were pioneers who had survived the journey to California, enduring harsh conditions to do so. They were not one to give up easily, and thereby the first levee project began. Two years later the next round of flooding hit and the initial makeshift levees failed miserably. But levees nonetheless would stay as the primary means of fighting floods.

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Hydraulic Mining in 1860s

In 1861, the largest flood in California history (to date) would hammer the Central Valley and then massive hydraulic mining would take off in the Sierras. The hydraulic mining led to tons of sediment and debris washing through the system, causing river bed elevation increases around the Yuba and the Feather (north of Sacramento) and leading to even worse flooding around Marysville and Yuba City. On top of that, vast areas of farmland were inundated with sand and mining debris, essentially ruining huge tracts of agriculture.

Running into Roadblocks

In the late 1860s, the next round of levee building would begin with the formation of the first levee districts. The problem was that the districts were still largely independent and building their own levees to protect their own interests. When one district or landowner increased the height of their levee, folks around them would have to respond in kind. Either build your own levee higher or go smash someone else’s levee taking pressure off your own – which happened often, especially in topographic pinch points on the Sacramento River (i.e. near the Sutter Buttes). The system was a mess and they were no closer to dealing with the “Inland Sea” than before.

For some time an argument of great seriousness and wide implications had been building up in the Valley, and it would go on for forty more years. The issue was a fundamentally simple one: what kind of river control theory should people rely on as they thought about flood control in the Valley? – Robert Kelley, “Battling the Inland Sea”

This debate is still going on right now in the Missouri and Mississippi Rivers! Levees, natural floodways (with loss of farmland), or a combination? This is not a new issue. In the 1870s in the Central Valley, It was time for the system to become a federal debate and problem to solve. In my next post, I’ll look at the development of the system in place and the impact of the Central Valley floods of 1986 and 1997.

Reference: Battling the Inland Sea by Robert Kelley (a tremendously fun and informative read!)

Part 2: History of Central Valley flooding to 1940s, the 1986 Flood

Part 3: The 1997 Flood and its impact

Part 4: Hurricane Katrina and the resulting actions in the Central Valley

Part 5: The current status of the Central Valley System, the lurking dangers

3 pings

  1. » The Next New Orleans? (Part 2) Hydraulically Inclined

    […] Orleans? The “Inland Sea” definitely had its flooding problems early on in its development. The flooding and failed disjointed levees of the 1850s and 1860s left the Central Valley of California at an impasse in their flood control problems. The issue was […]

  2. » The Next New Orleans? (Part 3) Hydraulically Inclined

    […] the potential for the disaster that hit New Orleans? It’s the question we’ve been examining. In Part 1, we looked at the Central Valley and Sacramento’s history up to the late 1860s. In Part 2, we […]

  3. » The Next New Orleans? (Part 5) Hydraulically Inclined

    […] Part 1: History of Central Valley flooding to 1860s […]

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