How much desalination reservoirs impact groundwater levels depend on the type of reservoir, their design, and the site conditions. Unlined or poorly sealed reservoirs may allow water to seep into the surrounding soil, potentially raising local groundwater levels. This can be beneficial in some cases, helping to recharge aquifers, but it may also cause problems such as soil instability, waterlogging, or contamination if the stored water interacts with the subsurface.
Lined or covered reservoirs, which are more common for storing treated desalinated water, are designed to minimize seepage. These reservoirs have little to no direct impact on groundwater levels, as their linings prevent water from escaping into the soil. Site selection also plays a role. In areas with shallow water tables, even small amounts of leakage from a reservoir could influence groundwater, whereas in deeper or well-drained locations, the effect is minimal. Environmental assessments often evaluate this potential before construction to prevent unintended consequences.
