Flowing Artesian Well Field Development in the Central Chi River Basin Project, Northeast Thailand

The flowing artesian aquifers in the Central Chi River basin are composed of a sequence of unconsolidated gravel, sand, silt, and clay units that were deposited by ancient rivers, the Chi River, and its tributary channel sediments. It is located in parts of Khon Kaen, Kalasin, and Roi-Et Provinces. While having been announced to be repeatedly a drought area, this area has been found to be hydrogeologically promising for a groundwater spring. The aquifers in this area consisted of an unconfined aquifer and two confined aquifers. The unconfined aquifer is composed of gravel, sand, silt, and lateritic soils. The thickness of this aquifer ranges from 10 to 30 meters. The confined aquifers are sandy gravel which is intercalated by clay layers. The depths to these aquifers are 30-50 and 40-150 meters, respectively. Many flowing-artesian wells were developed from not only unconfined but also confined aquifers with the potentiometric surfaces ranging from 0.5 to 8 meters above the ground surface. Three high potential areas were selected by the Department of Groundwater Resources to develop the flowing artesian well field pilot project for agricultural use. In each pilot area, three flowing wells 28 inches in diameters were drilled. The water from these wells was piped to five cylindrical fiberglass water tanks with a total capacity of 300 cubic meters. The irrigation piping system about 5000 meters long was installed and the agricultural group was formulated for the future sustainable management of this groundwater resource and its pilot system. Additional hydrogeological studies show that these aquifers are high productive aquifers and contain very good water quality, and can be the large source of drinking water. The detailed groundwater modeling, long-term monitoring of water levels, and chemical parameters will be conducted to ensure the sustainable development in this area.