A subsurface drainage assembly for directing fluid drainage from a surface
including 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.