A flow splitter including a first plate being immobile and a second plate being turnable with respect to the first plate. The first plate includes a central part, and the central part includes a slot and two side parts disposed at two ends of the slot, respectively. The second plate includes a first subplate and a second subplate, and the first subplate includes one end provided with a flange. The second plate is coupled to the first plate. The first subplate and the second subplate are disposed at two side of the slot; two sides of the second plate include two gaps, respectively. The two side parts of the first plate are disposed in the two yaps, respectively.

Provided is a structure for operating a watertight door by use of buoyancy. The structure includes: a detention tank for storing rainwater flowing from a street inlet; a buoyant member which is installed in the detention tank; and a sensor installed in the detention tank, in which if the buoyant member raised by the buoyant of the rainwater collected in the detention tank comes into contact with the sensor, the watertight door is automatically operated. The watertight door structure manually operated at localized heavy rain is improved, and the watertight door is automatically operated if the water level reaches the predetermined level.

Sewage flowing into a second water branching device is accurately controlled to separate into the following: sewage with a maximum sewage volume that can be discharged into a public water body W, the sewage sequentially passing through a first regulating tank, a first orifice, a second regulating tank, a second orifice, a third regulating tank and a third orifice to flow into a second discharge pipe; and sewage with an excess sewage volume, the sewage overflowing first to third overflow weirs to flow into an inflow pipe for a regulating reservoir.

Sewage flowing into a second water branching device is accurately controlled to separate into the following: sewage with a maximum sewage volume that can be discharged into a public water body W, the sewage sequentially passing through a first regulating tank, a first orifice, a second regulating tank, a second orifice, a third regulating tank and a third orifice to flow into a second discharge pipe; and sewage with an excess sewage volume, the sewage overflowing first to third overflow weirs to flow into an inflow pipe for a regulating reservoir.

The invention provides a modular unit or module (20) for use in an underground water management system. The modular unit or module (20) comprises a prism structure being a polyhedron enclosing a pair of internal members (6, 6′). The internal members (6, 6′) comprise a first member (6) comprising a first arch (9), and a second member (6′) comprising a second arch (9′) located at an angle to and being arranged inverted with respect to the first arch (9). The invention also provides a modular system (100) for use in underground water management, the modular system (100) comprising a plurality of the modules or modular units (20, 20′).

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.

Systems, methods, and articles of manufacture for automatic backflow identification, detection, remediation, and/or management. In some embodiments, a backflow management device may comprise a threaded and electronically-enabled plug installed in a non-pressurized pipe system cleanout, branch, or stub.

A drainage device is provided. The device includes a novel floating surface drain or skimmer to manage draining of liquid, such as draining of water from stormwater impoundment ponds or structures.

An underground stormwater management system comprising a sediment settling chamber, a plurality of stormwater management cells, and a trash capturing net. The sediment settling chamber has a sediment settling chamber floor and a discharge port located at a higher elevation than the sediment settling chamber floor. The plurality of stormwater management cells are located adjacent each other, and each cell comprises a body portion and an internal region, and is adapted to permit passage of stormwater into and out of the internal region of such cell. The plurality of stormwater management cells combine to form a stormwater management chamber downstream of the sediment settling chamber and in fluid communication with the sediment settling chamber. The trash capturing net is at least partially located within the stormwater management chamber and is adapted and configured to capture trash and debris in stormwater discharged from the discharge port.

Systems and methods for stormwater detention. An outer wall comprising L-wall members arranged side by side, each comprising a vertical stem having a height h and a width w, and a base of width w connected to the stem and extending outward therefrom at a horizontal angle. At least a first portion of the L-wall member stems having a pocket extending a distance d from a top surface of the stem towards the base, where d<h. The pockets may be positioned midway of the stem width. At least a second portion of the L-wall member stems devoid of a pocket. Optionally, support walls also having a pocket. A roof of double-T roof members each having a span, a flange, and two webs, the webs having first and second ends engaged with one of the pockets of the stems of the L-wall members.