An underlayment layer is configured to support an artificial turf assembly. The underlayment layer comprises plurality of panels, each panel comprising a core with a top side and a bottom side. The top side has a plurality of top projections. The top projections form top side water drainage channels. The panels have edges, with the edges of one panel abutting the edges of adjacent panels, thereby forming a drainage path between adjacent panels. The panel edges have vertical support extensions that extend into the drainage paths between adjacent panels. The vertical support extensions have an upper surface for supporting an artificial turf assembly overlying the turf underlayment layer, and the panel edges having one or more complementary indentations corresponding to vertical support extensions of adjacent panels. When the panels move toward each other, thereby closing drainage paths between adjacent panels, the vertical support extensions are received in the corresponding indentations.

An underlayment layer is configured to support an artificial turf assembly. The underlayment layer comprises plurality of panels, each panel comprising a core with a top side and a bottom side. The top side has a plurality of top projections. The top projections form top side water drainage channels. The panels have edges, with the edges of one panel abutting the edges of adjacent panels, thereby forming a drainage path between adjacent panels. The panel edges have vertical support extensions that extend into the drainage paths between adjacent panels. The vertical support extensions have an upper surface for supporting an artificial turf assembly overlying the turf underlayment layer, and the panel edges having one or more complementary indentations corresponding to vertical support extensions of adjacent panels. When the panels move toward each other, thereby closing drainage paths between adjacent panels, the vertical support extensions are received in the corresponding indentations.

A modular fluid retention system and method for exemplary uses collecting and temporarily retaining fluids, for example stormwater run-off. One example of the system includes a plurality of modular retaining units which are selectively connected together to form an interior chamber volume for collecting stormwater run-off directed into the chamber volume. A plurality of modular trays are engaged with portions of the respective retention units to prevent relative movement of the retention units and eliminate, or substantially reduce, the need for porous material to be installed in and around the retention units greatly increasing the excavation void space usable for water collection and retention. In an alternate application, only a plurality of modular trays are used as the vertical support and fluid retention volume structure for the fluid retention system.

A storm water drain tank module for assembly into a storm tank for storage of storm water includes a top platen, a bottom platen and a support spacer. The top platen has an upper surface and a top platen peripheral edge. The bottom platen has a bottom surface and a bottom platen peripheral edge. The support spacer is attached to the top and bottom platens to space the top platen relative to the bottom platen. A plurality of tabs and a plurality of slots are defined proximate the top and bottom platen peripheral edges, respectively. Each of the plurality of tabs extends outwardly away from the top and bottom platen peripheral edges, respectively, and each of the plurality of slots extends into the top and bottom platen peripheral edge. The plurality of slots is open in a lateral direction.

A storm water drain tank module for assembly into a storm tank for storage of storm water includes a top platen, a bottom platen and a support spacer. The top platen has an upper surface and a top platen peripheral edge. The bottom platen has a bottom surface and a bottom platen peripheral edge. The support spacer is attached to the top and bottom platens to space the top platen relative to the bottom platen. A plurality of tabs and a plurality of slots are defined proximate the top and bottom platen peripheral edges, respectively. Each of the plurality of tabs extends outwardly away from the top and bottom platen peripheral edges, respectively, and each of the plurality of slots extends into the top and bottom platen peripheral edge. The plurality of slots is open in a lateral direction.

A drainage unit has a plurality of modules defining channels with arced or flared surfaces longitudinally spaced from one another for installation into a ground excavation. The spaced modules may be aligned on a longitudinally support pipe that may provide a fluid connection between the channels. The adjacent surfaces of successive modules are spaced from each other a non-constant distance across the laterally transverse thickness or height. Filtration fabric that allows fluid flow therethrough while substantially filtering surrounding soil or other back fill is wrapped around each of modules. The flared and/or arced configuration of the modules defining channels allows for increased surface area interfacing between the channels and soil and a corresponding reduction in laterally transverse footprint.

A mechanically stabilized earth (MSE) wall system that permits water drainage through joints while also preventing undesirable migration of backfill through joints, thus dramatically reducing or eliminating undesirable vegetation by incorporation of a free draining seal (FDS) in panel joints, wherein the FDS structure blocks backfill but permits water migration.

A mechanically stabilized earth (MSE) wall system that permits water drainage through joints while also preventing undesirable migration of backfill through joints, thus dramatically reducing or eliminating undesirable vegetation by incorporation of a free draining seal (FDS) in panel joints, wherein the FDS structure blocks backfill but permits water migration.

An accelerated water removal low maintenance multi-hole golfing facility a plurality of golf holes and a plurality of water permeable and water shuttling sand bunkers. Each sand bunker has continuous bunker edge, a drain assembly, a synthetic tufted surface, a continuous integral edge overlapping polymer mesh, a non-woven dual smooth surfaced geo-textile, and a sand layer. Water flows from the continuous bunker edge over the synthetic tufted surface through sod the non-woven dual smooth surfaced geo-textile to the drain assembly preventing the drain assembly from clogging, thereby maintaining an unclogged drain assembly for the water permeable and water shuttling sand bunker.

An accelerated water removal low maintenance multi-hole golfing facility a plurality of golf holes and a plurality of water permeable and water shuttling sand bunkers. Each sand bunker has continuous bunker edge, a drain assembly, a synthetic tufted surface, a continuous integral edge overlapping polymer mesh, a non-woven dual smooth surfaced geo-textile, and a sand layer. Water flows from the continuous bunker edge over the synthetic tufted surface through sod the non-woven dual smooth surfaced geo-textile to the drain assembly preventing the drain assembly from clogging, thereby maintaining an unclogged drain assembly for the water permeable and water shuttling sand bunker.