Because of the potential for blow out of dams in drylands or monsoon areas, sometimes a very subtle and minimalist approach is the most successful. And sometimes the most subtle of changes can produce dramatic results.
The Zuni tribe used a line of single rocks around a mesquite tree or palo verde or other food source, to concentrate just enough water to help it to survive. It was similar to a fishscale berm, but with rocks.
Native Americans of the Southwest such as Zuni, Pueblo and Piute had some incredible earthwork technologies that allowed them to survive and thrive in these beautiful, but harsh and dry landscapes. One rock dam can gently help slow, spread and sink water.
Slow, spread, sink. One can continue to add earthworks that will spread the water through the landscape from here, and plant bushes and trees that can use the extra water to create a microclimate that will further protect the water. Permaculture earthworks, like so much else we do, can be a bootstrap operation completed with whatever is lying around (in this case, rocks).
This is subtle, no? But it will stop erosion, let water sink in, strengthen the plants upstream, inhibiting erosion further, and create more water availability in the area. Note that there is a lip of rock above and below the dam, otherwise new erosion can start below the dam or above it.
The Zuni bowl, pictured below, was used by Zuni people to control erosion and direct water for centuries. It’s very effective to stop erosion at the “headcut” or top of the erosive area. The entire streamflow becomes easier to control. The bowl can catch and store water for periods of time, creating a water source in the drylands that gradiently soaks into the soil and helps keep springs flowing.