Reservoir size has a significant effect on the overall cost of a desalination project, both in terms of construction and long-term operation. Larger reservoirs require more land, excavation, lining materials, and structural reinforcements, all of which increase upfront capital expenses. Covering a reservoir—often needed to protect water quality—also becomes more costly as surface area grows.
At the same time, bigger reservoirs can improve system reliability by providing more backup supply, which reduces the risk of service interruptions and the costs associated with emergency responses. They also allow desalination plants to operate at a steady output, which can lower energy costs compared to frequently ramping production up and down.
