Huehuetoca Tunnel Drainage Project in the Valley of Mexico

The Valley of Mexico is a closed basin that contained five interconnected lakes prior to the arrival of the Spaniards. As the Spaniards settled in the valley and began the development of present-day Mexico City, periodic flooding of the lakes threatened the urban development and the lifestyle of the people in the city. Over multiple centuries, New Spain and later independent Mexico constructed various hydraulic works to reduce flooding and to increase the land area available for development and farming. These hydraulic works eventually led to the complete drainage of the Valley of Mexico. This paper presents the engineering history of the first set of hydraulic works, whose centerpiece was a 6-km-long tunnel through the low hills near Heuhetoca in the northwestern part of the basin. The goal of the system was to reduce the inflow into Lake Zumpango, the most upstream lake in the northwest extent of the basin, which would reduce the overall flow into Lake Texcoco, on whose shores the capital city was built. This paper also discusses the social inequalities interwoven in the drainage project.