Subsurface Waters

Historically, legal concepts relating to ground water developed from the assumption that ground water was physically distinct and separate from surface water and that there were two principal classes of subsurface waters, namely, (1) underground streams of water flowing in known or ascertainable courses, and (2) percolating waters. It is now known that these assumptions were not well founded. All waters are interconnected through the operation of the hydrologic cycle, and with only a few exceptions, ground water percolates rather than flows in underground channels. Legal concepts relating to ground water developed rather independently from those relating to surface water. While the law governing underground streams is the same as that governing surface streams, the law governing percolating waters is essentially different.