A subsurface drainage assembly for directing fluid drainage from a
surface. The subsurface drainage assembly includes a plurality of drain
structure panels linked together in a manner that permits movement of one
drain structure panel relative to the adjacent drain structure panel. The
drain structure panels have a laterally extensive backing grid and a
plurality of spaced apart support members projecting therefrom. The
support members have at least one fluid flow opening formed through a
sidewall so as to intersect a lower end of the support members at two
rounded corners. The support members are spaced so that the support
members are nestable between the support members of an identical drain
structure panel when the drain structure panels are arranged in an
inverted relationship with respect to one another. The drain structure
panel may be placed on an impermeable liner having an upper surface with
a plurality of ridges defining troughs therebetween.