The Water Budget provides an indication of the amount of water demand and the subsequent stress on each sub-watershed region on the islands.
A simple accounting approach is used to compare the amount of water going into, and out of, the system.
When more water is taken out than is replenished, the system may be considered under “stress”.
Aquifer Stress Assessment:
When more water is extracted than replenished, an aquifer may experience stress. Aquifer stress compares the total demand for groundwater to the amount of natural aquifer recharge.
Watershed Stress Assessment:
When demand outstrips supply, a watershed may experience stress. Stress may be seasonal and variable. Surface water stress compares the total demand and minimum conservation flows to the amount of natural water supply and storage.