A field study on the assessment of the sustainability and quality of shallow groundwater resources for tobacco production was conducted in selected tobacco-growing areas in Batac, Ilocos Norte. Sustainability of groundwater supply of the aquifer system in the study areas was investigated based on groundwater supply and demand analysis, groundwater level fluctuation analysis, water quality evaluation, and water level-dependent fuel consumption rate. A simple groundwater model based on aquifer storage capacity and water balance of a finite area was developed to estimate the available groundwater supply. An estimated groundwater supply of 114,661 cubic meter per day based on the developed model, proved to be more than adequate to meet the existing water demand (4,239 cubic meter per day or 3.70%) and prospective increase in water demand for tobacco production. On the other hand, there is significant seasonal variation in the shallow groundwater level of the study areas as affected by rainfall, evapotraspiration, and abstraction rate. However, there is no indication of groundwater depletion during the study as all wells are fully recharged (530.56 mm/yr) during the wet season.
