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.

A wastewater leaching chamber having asymmetric corrugations running transversely along the length of the chamber, where each transverse corrugation has a wide section on one side and a narrow section on the opposed side of the chamber, such that the corrugation walls run at an angle to the longitudinal axis of the chamber. The widest corrugation side of the chamber has a large straight sidewall, and the corrugation forms an arch which curve across and downward from the top of the straight sidewall to the narrow side of the corrugation at the opposing base of the chamber. The asymmetric arch is comprised of a multi radius curve from the top of the straight side to the opposing base footer.

A Soil Absorption System SAS can include at least two elongate water dispersion trenches, channels or slots cut or formed into a surface or the ground, and filled with dispersal media, which can include stone. Each trench can be about 1-6 inches wide, about 4-48 inches deep, and laterally spaced a minimum of about 3-24 inches or about 3-12 inches apart from each other. This arrangement can provide increased lateral water dispersion surface area relative to lateral trench direction.

A method to enhance the ability of a stormwater containment volume to flow and flush solids and liquids. Implemented by depositing rock into shaped piles formed at the rock's angle of repose, the resultant inclined surfaces are covered with suitable waterproof material and covered with more rock up to the top surface. Stormwater flushes solids deposited on the surface downward into the volume where they contact the inclined surfaces. Water and solids flow down the inclined surfaces at increased velocity toward collection drainpipes at their base. Because sediment flows into drainpipes, it does not flow to the bottom of the volume or become stagnant or reduce the volume's capacity. This creates a low-cost stormwater containment system that can support vehicle travel on its surface, requires no concrete or sewers, is self-cleaning, accessible for cleaning, or both, and does not require human access to the bottom surface for maintenance.

A method to enhance the ability of a stormwater containment volume to flow and flush solids and liquids. Implemented by depositing rock into shaped piles formed at the rock's angle of repose, the resultant inclined surfaces are covered with suitable waterproof material and covered with more rock up to the top surface. Stormwater flushes solids deposited on the surface downward into the volume where they contact the inclined surfaces. Water and solids flow down the inclined surfaces at increased velocity toward collection drainpipes at their base. Because sediment flows into drainpipes, it does not flow to the bottom of the volume or become stagnant or reduce the volume's capacity. This creates a low-cost stormwater containment system that can support vehicle travel on its surface, requires no concrete or sewers, is self-cleaning, accessible for cleaning, or both, and does not require human access to the bottom surface for maintenance.

A system and method for an underground stormwater storage system which may comprise a pit, a structure, and a liner. The structure may be disposed within the center of the pit and surround by the porous backfill and wherein outlets are disposed on the crown of the structure. A liner may form the outer layer of the pit. A method for releasing stormwater may comprise capturing stormwater from a surface, containing the stormwater within a structure, releasing a volume of the stormwater from the structure and draining an additional volume of the stormwater from the crown of the structure from an outlet when the structure is capturing more stormwater than it is releasing.

In one aspect the present invention provides an adjustable head infiltration conduit configured to distribute water adjacent to the conduit and to convey water away from the conduit. This conduit includes a conveyance chamber defining a water flow path through the conduit, and at least one inlet port associated with one end of the water flow path defined by the conveyance chamber. Also provided is at least one outlet port associated with an end of the water flow path distal from said at least one inlet port, and an infiltration chamber in fluid communication with the conveyance chamber. This infiltration chamber includes at least one water permeable area configured to allow water out of the conduit. The infiltration chamber also includes at least one removable intermediate lateral baffle orientated substantially perpendicular to the water flow path defined by the conveyance chamber with the upper edge of said at least one removable intermediate lateral baffle defining the boundary of the infiltration chamber with the conveyance chamber. The removable intermediate lateral baffle or baffles forming at least two retention cells within the infiltration chamber arranged to temporarily store water before dispersal through at least one water permeable surface of the infiltration chamber.

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.

A molded plastic arch shape cross section stormwater chamber having a corrugated wall comprises separately molded half chambers which are connected by coupling features at a joint region at the top of the chamber, which coupling feature optionally includes at least one locking rod running lengthwise in proximity to the joint region. Preferably, the half chambers are made in the same mold and modified so they are mirror images of each other. The half chambers may be compactly stored and transported in nested condition. Near the point of use, the chambers may be assembled.

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.