The primary function of bibliographic citations is to assist the reader in finding the sources used in the writing of a work. To these basic citations, the annotated bibliography adds descriptive and evaluative comments (i.e., an annotation), assessing the nature and value of the cited works. The addition of commentary provides the future reader or researcher essential critical information and a foundation for further research.
French drain. A French drain or weeping tile (also blind drain, rubble drain, rock drain, drain tile, perimeter drain, land drain, French ditch, sub-surface drain, sub-soil drain or agricultural drain) is a trench filled with gravel or rock or containing a perforated pipe that redirects surface water and groundwater away from an area.
French drains are trenches that contain a perforated drain pipe which is surrounded by gravel. Either the entire trench is lined with filter fabric, or the pipe is wrapped in filter fabric. Generally, the trench is covered with grass. French drains are designed to remove water that is accumulating below the surface.