Groundwater dam.
https://www.emergency-wash.org/water/en/technologies/technology/groundwater-dam
👉🏼 PDF: https://app.box.com/s/6452sr900yvx138dshi7mj3jxl8qdpul _ A Groundwater Dam is a structure that slows or stops the flow of shallow groundwater, most often in seasonal riverbeds, increasing the availability of shallow groundwater upstream of the structure. The technology is not suitable for the acute or stabilisation phases of emergencies, and is more suited to long-term drought mitigation.