Presa Presidente Benito Juárez

The Presidente Benito Juárez Dam, also known as El Marqués, holds back the Tehuantepec and Tequisistlán rivers on the Isthmus, next to Santa María Jalapa del Marqués. President Adolfo López Mateos opened it on 1 January 1961, and when the basin filled in 1962 with 947 million cubic metres of water it drowned the original town, founded around 1480. Its people were moved to the side of the Cristóbal Colón federal highway, where Jalapa stands today. The dam was meant to irrigate some 57,000 hectares across nine municipalities around Tehuantepec and Juchitán, Irrigation District 019, set up in November 1962, though it has never reached that target.

The cemetery, schools, market and homes of what is now called Jalapa Viejo went under. Only the church of the Assumption, built by Dominican friars between 1550 and 1600 and counted among the finest in the Zapotec region, still stands. When the water drops, its two domes appear first, then the columned walls and finally the entrance arches. The full facade was first seen in the 1985 drought and came back in 2008, 2017 and 2024; its mural paintings are now scattered among INAH museums and storerooms.

The reservoir is a fishery too: about a thousand Jalapa fishermen, in cooperatives or on their own, catch tilapia, and the reservoir's mojarra is a big part of what draws visitors to eat in town. In droughts, when the catch is poor, some of them take visitors out to the church.