WillyLogan.com

Technology, History, and Travel

Tag: civil engineering (Page 1 of 4)

Where was Lake Texcoco?

Much of the land occupied by the great metropolis of Mexico City was once underwater. Before modern times, the Valley of Mexico was flooded by Lake Texcoco and adjoining bodies of water. The Aztecs founded their capital city, Tenochtitlán, on an island in the lake in 1325. Two hundred years later, Spanish conquistadors were astonished by the scale of the city and the causeways connecting the islands of the lake to the mainland. The Spanish conquered Tenochtitlán in 1521 and built their new colonial capital, Mexico City, on its ruins. Over the following centuries, engineers built drainage works to control the floods and eventually drain the lake almost completely. (A monument to one of these engineers, Enrico Martínez, stands next to the city’s cathedral.) All that is left of Lake Texcoco now is some marshland near the international airport on the east side of the city. Some canals on the adjoining lake to the south, Xochimilco, have also survived.

Monument to Enrico Martínez, one of the engineers who built drainage works on Lake Texcoco.

Monument to Enrico Martínez, one of the engineers who built drainage works on Lake Texcoco.

Some of the marshy remnants of Lake Texcoco, as seen from a flight out of Benito Juárez International Airport.

Some of the marshy remnants of Lake Texcoco, as seen from a flight out of Benito Juárez International Airport.

One of the surviving canals of Lake Xochimilco, a popular place for boat-rides in southern Mexico City.

One of the surviving canals of Lake Xochimilco, a popular place for boat-rides in southern Mexico City.

Where exactly was Lake Texcoco? When I have visited Mexico City, I have wondered what parts of the city were above-water (islands or lakeshore), and what parts are reclaimed lakebed. I thought that someone must have made a map of the modern-day city with the outline of the erstwhile lake superimposed on it, but I was not able to find one. So I made my own.

For the modern city, I used a 1:250,000 sectional chart that was jointly issued by the governments of the United States and Mexico in 2000. (It is part of the maps collection of the Perry-Castañeda Library of UT–Austin.) This map was a good find because it is big enough to cover the entire basin once flooded by the lakes, but it is detailed enough to include contour lines. For the outline of the lake, I used a map from Wikimedia Commons.

Map of the Valley of Mexico ca. 1519.

Map of the Valley of Mexico ca. 1519. (Source: Wikimedia Commons, CC-SA 4.0.)

I initially tried superimposing the lake map directly on the sectional chart, but I was never able to get the geographical points to line up. My second attempt (and this was successful) was to hand-draw the outline of the lake onto the sectional, using surviving Aztec place-names and contour-lines for reference. (I also had to use some guesswork.) Here is the result:

Map of Lake Texcoco and adjoining lakes superimposed over modern-day Mexico City.

Map of Lake Texcoco and adjoining lakes superimposed over modern-day Mexico City.

The map with the lakes labeled.

The map with the lakes labeled.

Some observations from this exercise of historical mapping:

  • A considerable portion of the erstwhile lakebed, including land to the east of the international airport, is still not built-up.
  • The marshes near the airport must have been the lowest part of the lakebed.
  • The western edge of the modern urbanized area, including such Aztec place-names as Chapultepec, Mixcoac, and Coyoacán, was on the western shore of the lake and thus was never underwater—except during floods. (Rule of thumb: places with Aztec names were at least partly above-water.)
  • But much of the city was underwater, including the most modern parts where there are high-rise buildings (Zona Rosa).

Now that I have made this map, I would like to see a detailed view of the territory around Tenochtitlán, which corresponds with the area around the Zócalo. Where exactly were the islands that the city was built on? But making such a map is a project for another time (and possibly another person as well).

Riding the meter-gauge rails

Broad-gauge (left) and meter-gauge (right) trains at Jaipur Junction.

Broad-gauge (left) and meter-gauge (right) trains at Jaipur Junction.

When private British capital first started building railroads in India in the mid-nineteenth century, the lines were built in broad gauge. With a spacing between the rails of 5 ft 6 in, this was, and still is, the widest rail gauge in common use anywhere in the world. The colonial Government of India started to build their own rail lines in the 1870s. These public-sector railways were more cheaply built than their private counterparts, and they were made in meter gauge (3 ft 3 3/8 in).

Even after independence and the nationalization of the private railways, broad-gauge and meter-gauge lines continued to be developed in parallel with each other. Only in the 1990s did the Indian Railways start to convert meter-gauge lines to broad gauge, under Project Unigauge. Since then, large stretches of meter-gauge lines have been replaced by broad gauge.

Meter-gauge lines survive here and there. One such line runs between Jaipur Junction and Sikar, 107 km (66 mi) to the northwest. Meter gauge used to run all of the way to Churu, another fifty miles to the north, but that stretch has recently been closed for conversion to broad gauge. (The time table posted in Jaipur Junction station still says Churu on it, although the name has been whited out and replaced with Sikar.) Someday the Jaipur–Sikar line will also become broad gauge. But in the meantime, seven meter-gauge trains will continue to run back and forth between Jaipur and Sikar every day.

Since meter gauge won’t be around forever, I felt obliged to ride the Jaipur–Sikar train when I had the chance. A month ago, I rode one of these trains from Jaipur as far as Chomun, one-third of the way to Sikar. The meter-gauge tracks at Jaipur Junction station are on the north side of the broad-gauge lines, so the tracks don’t have to cross each other. I found a place where both gauges run side-by-side, showing the difference in size.

Comparison of meter gauge (left) and broad gauge (right).

Comparison of meter gauge (left) and broad gauge (right).

The meter-gauge train was smaller and, I dare say, cuter than the broad-gauge trains I am used to seeing. Inside, the coach was just wide enough for a bench seating four or five adults.

Meter-gauge locomotive of 52083 Jaipur-Sikar MG Pass train.

Meter-gauge locomotive of 52083 Jaipur-Sikar MG Pass train.

Meter-gauge luggage car.

Meter-gauge luggage car.

Panorama of a compartment in a meter-gauge train.

Panorama of a compartment in a meter-gauge train.

I sat in the coach just behind the diesel-electric locomotive, because that one was farthest along the platform and nobody else was in it at first. When the train left Jaipur station, only two other men were in my compartment. At the first stop, Dher ka Balaji, the compartment filled up. The train passed by Jaipur’s sprawl for a while, then it reached the open countryside. After several station stops that I didn’t see the name of, the train pulled into Chomun station, a nice little colonial Public Works Department structure.

The single platform of Chomun Samod station.

The single platform of Chomun Samod station.

Glimpse of the facade of Chomun Samod station.

Glimpse of the facade of Chomun Samod station.

At Chomun, my meter-gauge technological tourism came to an end. I returned to Jaipur by city bus.

Having ridden on a meter-gauge train, I can now appreciate how much the Indian Railways have changed since the days when the narrower gauge was more prevalent. The train I rode to Chomun just didn’t have the capacity of the much larger broad-gauge trains I have ridden in India.

jaisamand-lake-pan

Jaisamand, Mewar’s superlative lake

View of the ornamented backside of Jaisamand Dam.

View of the ornamented backside of Jaisamand Dam.

In southern Rajasthan, thirty miles south of the city of Udaipur, twenty square miles of the Aravalli Mountains have been flooded by the remarkable Jaisamand Lake, formed by the 1500-ft Jaisamand Dam. Tourist guidebooks frequently erroneously refer to Jaisamand as the second-largest artificial lake in Asia. This is far from the truth; in India alone, a half-dozen artificial lakes are much larger than Jaisamand. What is remarkable about Jaisamand is the combination of its size and its age. The lake was built in 1685 on behalf of Maharana Jai Singh of Mewar. Jaisamand holds the undisputed distinction of being the largest extant pre-modern artificial lake in India.

Of the numerous Rajput kingdoms in medieval western India, Mewar was the last to submit to the Mughal Empire. In 1568, Mewar lost its capital Chittaurgarh to the army of Akbar after a long and bloody siege, but a royal remnant escaped to found a new capital at Udaipur. The Mughals tried to defeat Mewar again at the epic Battle of Haldighati in 1576, but Maharana Pratap Singh escaped with his life and his kingdom. (Alas, Pratap’s horse Chetak succumbed to his injuries during the battle, but he has since become a local hero in his own right.) Finally, in 1615, after a series of battles, Maharana Amar Singh was forced to accede to the Mughal Empire. This was more than fifty years after Amber became the first Rajput state to join the empire.

After getting dragged into the Mughal Empire, Mewar could redirect some of its resources from militarization to infrastructural development. Jaisamand Lake was one of the public works projects undertaken in the post-accession period. The lake stored water from the Gomti River, for use in irrigation. It also provided a setting for palaces and royal hunting reserves.

Jaisamand Lake has changed a little since the late seventeenth century. The original dam was refurbished around 1960. During the refurbishment, the historic front face of the dam was covered by a characterless concrete facade. The crest and backside of the dam, though, retain their historical appearance. A series of white marble steps lead down to the water. There are six stone chhatris (domed pavilions), six carved marble elephants, and a temple, Shri Narbdeshwar Mahadev Jaisamand. Despite some graffiti on the elephants, and the usual litter, Jaisamand Dam remains a place of historical importance and real beauty.

The steps on the backside of Jaisamand Dam.

The steps on the backside of Jaisamand Dam.

One of the chhatris on Jaisamand Dam. The white mark underneath the chhatri indicates the level reached by a flood in 1973.

One of the chhatris on Jaisamand Dam. The white mark underneath the chhatri indicates the level reached by a flood in 1973.

Pigeons fly over Shri Narbdeshwar Mahadev Jaisamand Temple, located front and center on Jaisamand Dam.

Pigeons fly over Shri Narbdeshwar Mahadev Jaisamand Temple, located front and center on Jaisamand Dam.

The characterless concrete face of the refurbished Jaisamand Dam.

The characterless concrete face of the refurbished Jaisamand Dam.

Jaisamand is accessible from Udaipur by Banswara-bound bus from the main government bus terminal near Udaipol. The dam and the lake are just up the hill from Jaisamand town, where the bus stops. Boat rides are available from the dam, at Rs 600 per boat for a half-hour or Rs 1200 for the full hour. On a hill just above the dam, a ruined palace stands on forest department land. Visitors can get permission to climb up to the palace from the forest department office, with payment of a fee. I thought the rate for foreigners of Rs 300 was ridiculously steep – even without the additional Rs 900 camera fee – so I opted out of that experience.

For further coverage of India’s pre-modern artificial lakes, please see my posts “Goodly Lakes” and “Another Goodly Lake.

Page 1 of 4

Powered by WordPress & Theme by Anders Norén