I’ve covered the fate of the inland seas in my science-fictional alternate history in a previous post, but I assumed that the Salton Sea would just be replenished to its historical peak levels. But what “historical peak levels” are is subject to change in an alternate timeline that diverges in 1900…
The Salton Sink undergoes a natural cycle where the Colorado River is diverted into the region and the depression (the place is 279 feet below sea level, almost as deep down as Badwater Basin’s 282 feet) is filled, forming a lake, which geologists call Lake Cahuilla (after the native American nation that lives in the area), that in due course evaporates, leaving salty desert land behind. In 1905 an accidental breach of a canal being constructed for irrigation purposes replicated this natural cycle, the water flowing freely from the Colorado River for two years before the leak was plugged. This two years of flooding created the Salton Sea as it was at its 20th century height.
What if the leak from the irrigation canal wasn’t plugged by 1907? What if the water proved too much for the engineers, and the flow just kept running wild? It’s a plausible outcome, and the end result would have been replicating more or less the ancient boundaries of Lake Cahuilla: once it reached a water level of around 30 feet above sea level, it would have started to flow out toward the Gulf of California, near Cerro Prieto, and into the Rio Hardy toward the Colorado River Delta.
For reference, a water level of 30 feet above sea level is almost 300 feet higher than seen today, and would have inundated the Coachella Valley up through Indio (approaching Palm Desert), as well as the entire Imperial Valley, including the city of Mexicali. But that might not matter much. In the 1900s the region was only lightly developed: Mexicali had less than 1000 residents as late as the 1910s.
The real impact would be the loss of one of North America’s most fertile regions for agriculture (if not the most fertile: three-quarters (!) of the winter vegetables Americans eat come from there)…and the gain of a massive freshwater sea in the middle of the desert, drastically altering the geography of southern California’s interior.
How altered? The Salton Sea is already fairly large for a lake; in this scenario it reaches about the same size as Lake Erie. Pretty impressive. There were probably spots in what’s now the Imperial Valley where you couldn’t see any land at all: only water in all directions, from horizon to horizon. That puts the “Sea” in Salton Sea.
Though “Salton Sea” really is a godawful name; better to name it the Cahuilla Sea, after the Indian tribe. Let’s roll with it in this timeline.
So what would the Cahuilla Sea be like? With its fresh water and its vast shoreline, it would become a magnet for recreational development, such as boating, fishing, and beach activities. The climate is hot and dry year-round: Palm Desert, which is near the northern shoreline, currently sports 70-degree days during the winter, with a bit less than three inches of rain per year. The presence of the water, especially at this extent, would most likely moderate temperature extremes, and lead to more humidity, but it wouldn’t fundamentally alter the hot desert nature of the climate: just look at Abu Dhabi, for instance, directly on and downwind of the even larger Persian Gulf, or places like Broome, Australia (directly on and downwind of the open ocean!).
The lake is vast enough that I could envision bands of lake-effect rain (and even snow in extreme cold waves) forming downwind of the lake after strong cold fronts, but these are not common. Well…until an extreme climate event wreaks havoc in a story I have in mind set in the mid 21st century, where an arctic front delivers lake-effect snow to the region in the middle of summer. But volcanic winters are always weird like that.
More intriguingly, with a direct outlet to the Gulf of California, the state of California gets a second stretch of coast, one of freshwater, much like the Great Lakes, one perhaps well-used by yachters and recreational boaters. Palm Springs could absolutely boom, much more so than it did even in real life, as a resort city. A whole expanse of such developments could cluster around the Cahuilla Sea, ringing it and appearing at night from space like a pearl necklace around the waters.
Evaporation of the lake would be a challenge…unless the Colorado River changes course permanently to flow through the artificial irrigation canal and then through the Rio Hardy via the Salton Sink (which it did multiple times before in its history, albeit by natural means). In any case nuclear desalination is trivial in this timeline, so more water from the ocean could just be pumped in.
All of this infrastructure and the management of both the sea, its ring of resort cities, and the Colorado River Delta would be cross-border, spanning both the United States and Mexico…or would it? After all, as of the dawn of the 1910s in this timeline the United States has committed a major oopsie by inundating Mexican lands that were earmarked for farmers, forcing the expulsion of Mexican settlers from the area, even submerging entire townsites. Not to mention robbing the Colorado River Delta of its water for years on end as the Salton Sink filled.
It’s not hard to imagine that the United States would, either de facto or more intentionally, take complete control of the disaster response and thus acquire a much greater interest in the area’s governance, even as Mexico is incensed at the Americans’ error. A purchase of the area by the United States would be the obvious move: Mexico gets its compensation, the United States (the instigator of the error) gets to manage the entire area, and that’s the end of it. Well…except for how Mexico would now lack a direct land connection to the Baja California peninsula, but rights to access the area for the purposes of building and managing infrastructure could easily be provided to Mexico as part of such an agreement.
The end result: an expanded United States of America, one that encompasses the entirety of the Salton Sink, including the Mexicali Valley, and the Colorado River Delta.
It’s worth noting that such an agreement would be more feasible back then than it would be today, since the region was very sparsely populated by Mexicans (or Americans). Even today it isn’t much of a population center outside of Mexicali.
It’s possible the United States purchases just the Mexicali Valley and the Colorado River Delta itself, but since this would effectively extend Arizona southward to the Gulf of California, it’s possible that the United States might be interested in including some tracts of desert in the deal. This would give the United States more possibilities for a port on the Gulf of California coast, a key geostrategic interest. If Arizona’s southernmost straight-line border is just extended westward (rather than diverting a bit to the north as is the case today), then Puerto Peñasco becomes a part of Arizona, along with the desert regions to the north.
It’s a subtle change, but the northernmost coast of the Gulf of California has beautiful beaches, sublime deserts, and a hot, dry, and sunny climate, all of which is perfect for tourism. Start with the construction of port facilities for the state of Arizona, with direct links to Tucson, Phoenix, and beyond, and end with the entire coast being a vacationland. Move over, Florida: there’s a new Sunshine State with beaches on the block!
Even as it is Puerto Peñasco as well as the general area is commonly known as “Arizona’s Beach”, since so many Arizonans go there for tourism. The place has always only been weakly tied to the rest of Mexico: the very name Puerto Peñasco comes from a British sailor, Robert William Hale Hardy, who named the place Rocky Point (the current name is just the Spanish translation).
In this world, given its attractions, as well as the need for new port facilities owing to the explosion of international trade, I could envision Puerto Peñasco exploding as one of Arizona’s largest and most important cities…which is saying a lot, since the Desert Southwest in general in this timeline becomes one of the most populated regions of the United States (the Sun Belt migration concentrates there and largely passes by the southeast). Certainly the Gulf of California’s coast would become very popular: it has the ideal sunny beach climate, and with the advent of nuclear desalination water supplies are no longer a constraint.
The Colorado Delta Region in general might be much more prominent: as part of the United States it would be less of an afterthought, and the advent of nuclear technology makes all the dams that have robbed it of its water superfluous. Structures like Hoover Dam would be dismantled…a tall task, considering how huge it is, but in a world with nuclear explosives (which are commonly used for civilian purposes) it’s eminently surmountable. Great care would need to be taken to manage reservoir discharge, eliminate excess sediment, et cetera, but it could be done.
In any case, the water from the river runs completely wild, as nuclear desalination takes over as the water source for the people. The ecology is restored completely in all its glory. Which apparently was glorious indeed:
On the map the Delta was bisected by the river, but in fact the river was nowhere and everywhere, for he could not decide which of a hundred green lagoons offered the most pleasant and least speedy path to the Gulf.
So went the description by Aldo Leopold, from “A Sand County Almanac”, describing the Colorado River Delta in 1922. In this world that might also describe the Colorado River Delta in 2022. What a world that would be. What a world…