Why do closed lakes have no way to remove water except through evaporation or seepage?

Closed lakes, often associated with playa environments, are defined by their lack of an outlet. Unlike open drainage systems where water flows into a stream or river network that eventually reaches the ocean, a closed basin is geographically isolated by its surrounding topography.1

Because these basins lack a surface drainage outlet, water that collects within them cannot exit through traditional riverine flow. Consequently, the water balance is governed entirely by the relationship between inflow (such as precipitation or runoff) and the loss of water through evaporation or seepage. In arid or semiarid regions, high rates of evaporation often exceed the rate of water supply, causing the lake to shrink or disappear entirely, leaving behind a dry, salt-crusted surface known as a playa. Seepage—the movement of water through the soil—serves as the only other mechanism for water loss, depending on the permeability of the underlying basin floor.234