These aren't large scale projects across rivers, but just enough to capture the run-off on one's own property. Mostly you are improving soil retention, and refilling the aquifer. Often times it's as simple as creating repeated depressions in the desert so that dust, seeds and wind blown matter can collect along with just enough water to start plant growth so that the topsoil can be stable once again.

Stopping is different from slowing. Slow water keeps streams from drying up in the summer. Lots of stories of seeps and seasonal streams coming back after years of having dried up.