Artificial recharge structures like check dams and recharge shafts are used in Tamil Nadu to improve groundwater levels. These structures help replenish groundwater, especially during monsoon seasons. Compared to natural recharge, areas with artificial structures see a much greater increase in groundwater levels. Recharge shafts in percolation ponds are particularly effective at recharging groundwater. Overall, these structures play a crucial role in managing and restoring groundwater resources in hard rock regions.