Mexico’s Santa María dam 36% complete

Mexico’s water authority Conagua has advanced 36% with construction of the 16.3bn-peso (US$786mn) Santa María dam in Sinaloa state, a year after the administration of President Andrés Manuel López Obrador (AMLO) decided to resume the unfinished project. 

The highlighted milestones include major advances in the excavation of the three 16m diameter tunnels (pictured) that make up the deviation works of the dam, according to an update video presented Monday during AMLO’s morning press conference. 

Tunnel one is already fully excavated, while tunnels two and three are 92% and 84% dug, respectively. 

Santa María is located on the Baluarte river in El Rosario municipality. Construction originally began in 2015 under the administration of former Enrique Peña Nieto, but progress was repeatedly halted.

After AMLO pledged to resurrect the project and complete it by the end of his term in 2024, works resumed in December 2020. 

The company that is leading construction is Mexican infrastructure giant ICA, Conagua said, adding that the project has four fundamental objectives.

These are to irrigate 24,250ha, which will benefit some 2,500 users; to generate electricity; to protect the Escuinapa and El Rosario municipalities from floods; and to bring clean water to 430,000 residents. 

According to the project’s cost and benefit analysis, available in the investment portfolio of the finance ministry (SHCP), the dam wall will have a maximum height of 153m and a length of 784m.

The reservoir will have useful storage capacity of 723Mm3, according to Conagua, Two Francis type turbines of 15MW will generate 231GWh a year. 

Under the recently approved 2022 federal spending budget, the AMLO administration proposed allocating 5.1bn pesos to the dam next year. It is the dam project with the most federal funding out of five. 

At the end of August, Conagua said the project was 27.5% complete.

Works at the Santa María dam in Sinaloa state / Photo credit: Conagua