Natural or Not?

If man flooded it, can it still be considered natural?

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“Why don’t we just let the Salton Sea dry up and return to its natural state?”

“The California Development Company flooded it. Why don’t they pay to fix it?”

Have you heard any of these questions, or even thought them yourself? You are not alone. Many people who begin to learn about the Salton Sea arrive at these inquisitive conclusions shortly after learning about the “Great Diversion” of 1905. But let us revisit together some historical facts and observations, and ask ourselves, “Is the Salton Sea natural or not?”

Located near the mouth of the Colorado River, the Salton Sea sits well below sea level. It has naturally been filled by the Colorado River many times due to the dynamic nature of the river delta. [1] Formed where the river meets relatively still water, the delta evolves as the Colorado River carries and deposits large amounts of sediment from its 1,450 mile journey when it reaches the Gulf of California. The Gulf is too calm, relatively, to carry that sediment away, so it builds up over time. When the silt is sufficiently deposited, it creates a barrier to the Gulf. The Colorado River must find a new path, and logic dictates water will find its way downhill. This also occurred during years of heavy rainfall, when the Colorado would overflow its banks and flow wherever gravity led it. And when the same thing happens to the Salton Sea, when the carried sediment builds up sufficiently, the Colorado River heads back to the Gulf of California. When this happens, and the Salton Sea no longer has an inflow of water, it slowly but surely evaporates away and is left a dry lake bed.

Colorado River Basin; Salton Sea is in the lower left-hand corner. (Source US Bureau of Reclamation,

This is how early settlers found it in the late 1800s; dry. People quickly recognized, as they did throughout California, that this basin (current day Imperial Valley and Coachella Valley) was an ideal place for farming. With seemingly endless sunshine year round, fertile soil, and moderate winter temperatures, all they needed was an irrigation source. With the Colorado River running so close, it was an obvious choice to tap into.

Pretend with me, that in 1905 the California Development Company had constructed a sufficient canal to siphon off Colorado River water without it failing. Most of the river would continue towards the Gulf, and the farmers would have an enormous supply of fresh water for their fields. Since the valley rested below the altitude of the river, gravity would do the work of moving the water. All the farmers had to do was construct their fields in such a way to keep the water moving downhill.

Remember, we’re pretending the Great Diversion of 1905 never happened.

As the farmers irrigated their fields via flooding, it was obvious that the agricultural runoff had to flow somewhere. Continuing with the easy mechanism of gravity transport, that runoff would have found the lowest point in the valley. That lowest point was, and still is, the dry lake bed of the Salton Sea.

With around 500,000 acres of land to be used for farming, this meant an enormous amount of runoff would be flowing downhill into the dry lake bed, slowly filling it, but still faster than evaporation would take it away.[2] This runoff contained large amounts of salts from the soil, and also fertilizers and pesticides being used by the farmers.


Had the Great Diversion never happened, and had the Salton Sea not been filled up by 2 years of uncontrolled Colorado River inflows, it still would have been eventually filled with agricultural runoff. It would not have been as massive as it was between 1907 and 1960, and it would probably have never been the tourist destination it once was. It probably would not have been able to support as much diverse wildlife for as long as it has. But it would still be there, smaller, and much saltier than current day. This means there would be more emissive playa today, and a vastly different ecosystem.

When one thinks about it that way, I conclude that it is easy to see that we should be thankful for the California Development Company’s failure that resulted in 2 years of freshwater for the Salton Sea. Otherwise, we would not be able to enjoy it as much as we have and as much as we still do.

What this does not change, is the fact that the Sea is in trouble. The flood simply delayed the time before action was needed. We must now focus our efforts on keeping the playa covered with water, and supporting the ecosystems. Projects like the Red Hill Bay Restoration Project are an excellent start. We need more of that kind of deliberate action. Action that will show results quickly, and without high costs.

Thankfully, the CA Natural Resources Agency is under great leadership and is actively working on reporting to the State Legislature additional shovel-ready projects. Governor Brown’s latest proposed budget included an $80M increase of funds for Dept. of Water Resources “to design and implement projects that expand habitat and suppress dust at the Salton Sea…” [3] Some will say that’s not enough money to fix the problems at the Sea, and that the State isn’t serious about restoration. And while their negativity is toxic to the communities involved, they are correct by saying $80M will not make the Sea’s issues disappear. But it’s certainly better than nothing, and those who truly care about the Sea won’t look a gift horse in the mouth.

So “Yes,” the Salton Sea is a natural phenomenon. Its current rendition has been affected heavily by man, for better or worse, but that has no bearing on the fact that action must be taken soon to avoid public health and ecological disasters.


[1] Brothers, Daniel, Debi Kilb, Karen Luttrell, Neal Driscoll, and Graham Kent. “Loading of the San Andreas Fault by Flood-induced Rupture of Faults beneath the Salton Sea.” Nature Geoscience 4, no. 7 (2011): 486-92. Accessed January 12, 2016. doi:10.1038/ngeo1184.
(Thank you to Jenny Ross for the reference)

[2] Connie L. Valenzuela, “2014 Imperial County Agricultural Crop and Livestock Report,” Imperial County, accessed December 31, 2015,

[3] “Natural Resources.” Governor’s Budget Summary. January 7, 2016. Accessed January 13, 2016.


2 thoughts on “Natural or Not?”

  1. the other side of the coin is if no one ever interfered with any of the of the Colorado river water. Or the lower river channels. there is a good chance that the Colorado river would have changed course and filled the old lake bed anyway. there was a weather event called the little ice age that caused a drought in the south western areas. this was ending in the late 1800’s at about the same times floods from the Colorado were occasionally reported entering the basin. Human interference has kept the river in one “Main” channel when prior to such interference the river bed changed channels frequently, The story of Hardy’s Colorado is an example of how the flow used to change riverbeds.


    1. Hi Luann,
      Thanks for your input! I definitely agree with you that it is quite possible that the Colorado River would have flooded the basin again were it not for man “taming” the river with canals and dams. That is, quite simply, the impetus of my article. If agricultural settlers had arrived while the basin was currently filled, how do you think the area would be different today, if at all? I suspect farmers would still have tried to divert surface water, and would still need a sump for runoff, so I imagine we would be in a similar predicament. Except for the fact, maybe, that people would more easily understand that the Salton Sea is natural.

      Thanks for reading,
      Drew Story


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