Question

Read the following passage from an article about traditional resource management:

In the semi-arid mountains of southern Spain, a quiet revolution is taking place. Local communities, facing prolonged droughts exacerbated by modern climate change, are turning to medieval solutions. Volunteer groups and environmental scientists have partnered to restore hundreds of miles of ancient irrigation canals originally built during the Moorish agricultural expansion. These gravity-fed earth channels, which had been abandoned for decades in favor of modern piped systems, are proving to be surprisingly resilient. By slow-filtering mountain meltwater into the soil, they recharge underground aquifers and sustain local ecosystems during dry summers. While modern intensive agriculture relies heavily on energy-demanding pumps and depletes deep water reserves, this historic gravity-based model works in harmony with natural cycles. Supporters argue that the revival of these networks is not merely an exercise in historical nostalgia, but a practical, cost-effective strategy for climate adaptation. However, challenges remain, as the traditional knowledge required to maintain the soil channels is held by a dwindling generation of elderly farmers, and current agricultural subsidies disproportionately favor large-scale, automated irrigation.

According to the passage, which of the following is the primary reason why local communities and environmentalists are restoring the ancient gravity-fed irrigation canals?