BEHAVIOR OF GROUNDWATER LEVELS IN TEXCOCO AQUIFER (1507) WHEN THEY ARE LOWERED BY EXCESSIVE PUMPING FROM 1968 THROUGH 2014

Abstract. Increasing water demands in groundwater resources have overstressed aquifers in Mexico. These Demands have caused that groundwater volume in storage has decreased. Texcoco Aquifer (TA) is located in the Valley of Mexico. It has 12 municipalities, area of 939.04km² and 2 846 559 population. In 2014, the water balance showed a recharge 145.10 (Millions of Cubic Meters (MCM)), a withdrawing of 256.88 MCM, deficit of 111.78 MCM CONAGUA 2015. This shortage has TA as one of the most critical and depleted aquifer in Mexico. This paper presents 10 hydrographs of 35 wells selected from 104, from 921 total. Charts offer a good visual representation of long-term groundwater declines due to excessive pumping in 46 years. Groundwater level decline rate in northern area of TA is 1.04 meter per year (m/y) (Chiconcuac), in southern 1.31 m/y (Chicoloapan), in southeastern 1.27 m/y (Coatlinchan), in the Eastern 0.76 m/y (Tepetlaoxtoc), in Center East 1.24 m/y (San Simon) and center west 1.15 m/y (Chapingo). In spite of these data, there are decline rates from 1.2 to 3.8 m/y, being maxima in the south. Average decline rate from 1968 to 2014 is approximately 1.21 m/y, In addition, decline trends are increasing rapidly for last five years. Finally, to obtain sustainable aquifers, government most apply severe policies, in coordinating among federal, state and municipal entities for preserving TA, enforcing efficient use of water. If TA were depleted, we would have to import water from more distant and expensive sources, as It has happened in Mexico City