Agriculture is critically dependent on continuity of clean water supply. Where there is a significant ashfall, clean water will likely be in short supply. Natural water sources and man-made ponds may be temporarily contaminated by ash, and water-pumping equipment can be damaged by the abrasive rock particles (covering with tarps may provide protection).
Minimal ash coverage can disrupt water supplies due to known issues: acidification, increases in turbidity and ionic concentrations. In addition, delivery systems may be blocked or damaged by hard and abrasive suspended ash and related ash-cleanup operations place extra stress on water reserves. Restoring quality water supplies for livestock is typically a high priority if livestock are to remain on land affected by ashfall.