Flow control methods and devices

A flow control device for use in a stormwater storage area that accumulates water during a storm event and drains the accumulated water from the storage area through an outlet pipe, the flow control device to delay the maximum rate of discharge of water from the storage area until after the water in the storage area falls from a first water depth to a second, lower water depth, the flow control device comprising:

• an intake pipe extending along a pipe axis and having axially opposite first and second ends spaced apart by a length of the pipe, a first portion of the intake pipe disposed at the first end and having an opening configured to flow the water into the intake pipe when the intake pipe is immersed in the water;
• a float body having a waterline that defines a horizontal plane through the float body, the float body configured to float on the water in the stormwater storage area at the waterline, the float body comprising a lower end spaced in a downward direction from the waterline, the lower end immersed in the water below the waterline when the float body is floating on the water;
• and
• a rigid hanger connected to the float body and to the intake pipe whereby the intake pipe is connected to the float body, the hanger comprising a first end portion and an opposite second end portion, the first end portion being disposed between the lower end of the float body and the waterline and fixedly connected to an intermediate portion of the intake pipe spaced along the pipe axis away from the intake pipe opening towards the second end of the intake pipe and with the first portion of the intake pipe extending away from the hanger to the first end of the intake pipe, the second end portion being disposed above the lower end of the float body and pivotally attached to the float body and pivotable with respect to the float body about a pivot axis spaced away from the first end portion of the hanger in a direction transverse to the pivot axis, the pivot axis being spaced from the intake pipe opening by a distance along the pipe axis from the intake pipe opening towards the second end of the pipe, the hanger pivotable with respect to the float body in a plane transverse to the pivot axis through a range of motion having a lowered position wherein the pipe axis is inclined with respect to the waterline at a first angle and a raised position wherein the pipe axis is inclined with respect to the waterline at a second angle greater than the first angle, the intake pipe opening being closer to the waterline when the intake pipe is in the raised position and the intake pipe opening being farther from the waterline when the intake pipe is in the lowered position, so that the intake pipe opening is movable towards and away from the waterline with pivotal movement of the hanger with respect to the float body.