These methods tend to take more labor, or machinery, or engineering know-how, or all three. These are some common permaculture methods used to increase water access to large farms or ranches, or to revitalize degraded watersheds.
In drylands, water catchment can be challenging because rainfall is intermittent and often comes in monsoons, a great volume in a short time period, when it does come. The evidence of this is in the deep canyons in drylands areas we are so familiar with like the Grand Canyon, or the Badlands in the western US. This can happen in more humid areas as well, during hurricanes or heavy storms. Flash floods can happen anywhere. In wetter areas they often happen when the ground is already saturated. Both earthworks and stands of trees or perennial grasses can prevent destructive flooding.
The main purpose for earthworks though, is to bring water to plants during drought. Our farm is located on a sandhill in Florida. We normally have an 8 month dry season here. Many of the water catchment techniques for drylands work well for our trees. Keep in mind that these large scale approaches can be modified, scaled down and used in urban small scale settings too.