What is the rule that allows landowners to capture all the water under their land called?

The rule that allows landowners to capture all the water underneath their land is known as "absolute ownership." This principle grants landowners the comprehensive right to extract and use groundwater without significant limitations. Under absolute ownership, the landowner is considered the rightful owner of all the water that flows beneath their property, much like other natural resources.

This concept is rooted in the idea that landowners have full control over the resources located on their land, including the water that is present underground. As a result, they can utilize it for various purposes, such as irrigation, drinking water, or other uses necessary for their needs.

In contrast, other doctrines like reasonable use, riparian rights, and correlative rights impose certain restrictions or require sharing water resources under specific conditions, emphasizing conservation and fair distribution among users. These principles focus on the responsible usage of water to prevent over-extraction and to balance the needs of multiple users, which is not a concern under the absolute ownership rule.