Apparatus for stormwater retention and release, and method of use thereof

A method of retaining and controlling discharge of stormwater collected by drainage means fitted to a building, the method comprising the steps of:

• collecting stormwater by drainage means;
• retaining the stormwater by a stormwater retention apparatus comprised of a closed container which is located underneath or proximal to a building of the property, being connected by at least one inlet conduit to drainage means sourced externally from the building to receive stormwater into the container, and being further connected to at least one outlet conduit by which stormwater is led away from the container and a control chamber with which the container is in fluid communication and through which stormwater enters and is to be stored in, and leaves the container when the stormwater reaches a determining level in the control chamber spaced above the base of the container, wherein the inlet and outlet conduits are connected to the control chamber and thereby to the container, and that the outlet conduit comprises an end portion which passes out of the control chamber and includes an entry spaced above the determining level by which stormwater can pass from the control chamber into the end portion to exit from the control chamber, and which by being spaced above the determining level allows stormwater to collect in the container and control chamber above the determining level;
• and
• controlling release of the retained stormwater by the stormwater retention apparatus into local drainage facilities.