How do the Kuiseb River’s underground waters supply Walvis Bay and Swakopmund?

The Kuiseb River is an intermittent watercourse that typically dies out in the Namib desert before reaching the Atlantic Ocean. Because the region is almost rainless, the river does not maintain a permanent surface flow.12

However, a portion of the water from the river seeps through the sands of its streambed. This underflow is tapped approximately 25 miles (40 km) inland to provide essential water supplies for the coastal towns of Walvis Bay and Swakopmund.2