To Dave & all interested: Tile or drain tile are agricultural drainage tile. Some areas of the country use them on farms more than others. Modern drain tile are made of ribbed tubular plastic with perforations to allow soil water to enter the tile and then be drained into a header tile or directly into a ditch. Old style drain tile were made of clay or cement (cylinders of various dia abt 16" long) that were laid underground (5' to 6' deep) end to end to drain water out of the subsoil in farm fields. Many of the dug ponds in agricultural areas are built in areas where drain tile had been previoulsy laid in long "strings". A "string" of tile near the pond wall will drain water away from the pond. Water can seep into the tile through soil from as far away as 20 to 30 ft. If an unknown tile string is relatively close to a pond wall the tile will draw waterout of the pond down to the level of the tile string then the seepage or water loss seems to stop and stabilize there.

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