Restoration efforts, with USFWS funding support, began in December 1991 with the Onion Bottom site, an area that historically grew mint and onions.  After abandonment, exotic reed canary grass infested the east half, with lowland tree species establishing on the west half.

Breaking/plugging existing agriculture drainage tile lines and installing a passive water control structure restored a more natural hydrology.  This resulted in an 11-acre marsh wetland community.

Onion Bottom pre-treatment with reed canary grass infestation on saturated abandoned agriculture muck soils. (August 1991)

Subsurface drainage tile line location identified by excavating perpendicular to expected drainage outlet flow. (Dec 1991)

Tile located and broken by excavation along a section of its length. (Dec. 1991)

Outlet tile from drainage basin is blocked to interrupt original drainage flow.

Intact outlet tile that drains project area is backfilled (Dec. 1991)

New plastic tile is connected to intact  underground drain tile, an anti-seep collar installed and the open end of the new tile line is placed at the elevation of the designed high water level of the restored wetland basin.
Once backfilled, this passive waster control structure will drain away excess water that exceeds the designed high water level. (Dec. 1991)
Onion Bottom (upper left), after its initial 1991 restoration, with residual snags providing excellent red-headed woodpecker habitat. (Sept. 2011)