A water detention chamber, and a system constructed from multiple such chambers, is an arch-shaped corrugated chamber having a flange having an upper surface and a lower surface. The lower surface of the flange has one or more protrusions, preferably elongated members, at the first end of the chamber. The upper surface of the flange has one or more mating apertures or cavities formed therein. Multiple such chambers can be connected to each other in an end-to-end fashion with protrusions at the first ends of a chamber engaged with apertures or cavities at the second ends of a second chamber.

A water detention chamber, and a system constructed from multiple such chambers, is an arch-shaped corrugated chamber having a flange having an upper surface and a lower surface. The lower surface of the flange has one or more protrusions, preferably elongated members, at the first end of the chamber. The upper surface of the flange has one or more mating apertures or cavities formed therein. Multiple such chambers can be connected to each other in an end-to-end fashion with protrusions at the first ends of a chamber engaged with apertures or cavities at the second ends of a second chamber.

A method of making a molded plastic arch shape cross section stormwater chamber having a corrugated wall comprises molding half chambers which are connected by hinges at a joint at the top of the chamber. The chambers may be compactly stored and transported in splayed out configuration. Later, upward force is applied to the hinge joint location of each chamber, so the half chambers are rotated by force of gravity, whereby a faying surface on each half chamber is urged toward the like surface of the other half chamber. The faying surfaces are then fused to each other, preferably as a result of prior heating or by melting of a fusion weld element that is captured in the space between the faying surfaces.

A subsurface fluid conveyance chamber is arch-shaped in cross-section, having a corrugated outer shell extending along a horizontal axis with a pair of contiguously molded end walls and alternating peak and valley corrugations along its length. Each peak corrugation forms an outer ridge having a top surface and a pair of sidewalls. Inner walls along each lateral side of the outer shell form interior chambers at each ridge location in the outer shell. Each interior chamber has an aperture formed in the inner wall, and two opposing apertures formed in each sidewall. The inner wall apertures are vertically offset above the outer shell apertures and form a gravity trap for the granular material, limiting entry to the lower section of the interior chambers. The angled pathways defined by the interior chamber aperture locations require directional changes in fluid flow that minimize contamination of the inner conveyance chamber during use.

A plastic chamber for collecting, receiving, detaining, or dispersing water when buried is provided and includes a support pillar having at least one pillar wall which defines a pillar cavity. Additionally, the chamber includes a plurality of chamber ends, a plurality of chamber side walls and a chamber top, wherein the chamber top includes a pillar opening and wherein the chamber defines a chamber internal cavity. It should be appreciated that the support pillar extends downwardly into the chamber internal cavity from the chamber top, wherein the pillar opening is communicated with the pillar cavity. The pillar cover is movably configurable between a first configuration and a second configuration to uncover and cover the least one pillar opening.

A plastic leaching unit for receiving water when buried in trenches in soil comprises a plurality of pillars interconnected by struts. A canopy made of sheet material is attached to the tops of the pillars. The pillars are arranged as spaced apart integral assemblies to enable lateral and vertical bending of the leaching unit, for conforming to a not-straight trench. Preferably, the canopy comprises a second perforated sheet overlying a first sheet having larger perforations, the combination arranged for flow of water and gases while hindering soil particulates. Preferably, the canopy extends a greater amount from the first end of each unit than from the second end, to facilitate end-to-end mating of the units. Leaching units may be stacked one upon the other within a trench.

Individual hexagonal shaped modules used in an assembly for underground storage of storm water and other fluid storage needs. Modules are assembled into a resultant honeycomb shape for maximized structural strength and material use efficiency. Adjacent modules are in direct fluid communications with one another via openings or windows in module side walls. Assemblies include various top and side pieces along with access ports for entry into said assembly.

An improved liquid run-off disposal system is described having an infiltration chamber 72 with first and second sidewalls 74. In cross-sectional view the first and second sidewalls 74 each include an inner surface 76 and outer surface 78, and each sidewall 74 includes a plurality of integrated louvre-shaped apertures 80. In cross-sectional view each louvre-shaped aperture 80 includes an upper surface 82 and a lower surface 84 which are angled upwards from the outer surface 78 and protrude inwards from the inner surface 76 into the interior of the infiltration chamber 72. The upper and lower surfaces 82, 84 comprise a plurality of angled sections, the angled sections being arranged so as to form a substantially vertical flow path through a portion of the aperture 80. The angled sections of the upper and lower surfaces 82, 84 are arranged at an angle and of a length so as to substantially overlap when viewed in a horizontal direction. The overlapping region Y.sub.1 ensures that the apertures 80 will admit the exit of water but substantially inhibit the entry of soil wherein, in use, when liquid run-off is piped into the infiltration chamber 72 it can drain away through the apertures 80 and into the surrounding soil.

Individual hexagonal shaped modules used in an assembly for underground storage of storm water and other fluid storage needs. Modules are assembled into a resultant honeycomb shape for maximized structural strength and material use efficiency. Adjacent modules are in direct fluid communications with one another via openings or windows in module side walls. Assemblies include various top and side pieces along with access ports for entry into said assembly.

A plastic arch-shape cross section corrugated stormwater chamber has a multiplicity of crest corrugations and valley corrugations which run transverse to its length. Sub-corrugations run along part or all of the arch-curve lengths of either crest corrugations or valley corrugations, or along both of them. A sub-corrugations are smaller in dimension than an associated crest corrugation or valley corrugation. Sub-corrugations may taper in width and depth and may taper to nothingness. A compound convex shape end cap, useful for closing off the ends of stormwater chambers, has substantially vertical corrugations with analogous sub-corrugations.