Utilizing debris basins for stormwater retention

Abstract

Utilizing debris basins for stormwater retention.

Claims

1. A method for utilizing debris basins for stormwater retention, the method comprising: an open channel disposed to convey stormwater; a debris basin across said open channel comprising a dam equipped with an overflow spillway, at least one inlet structure upstream of said dam, and at least one outlet pipe; enclosure around and atop said inlet structure(s) disposed to prevent water from entering said structure(s) and inlet pipe(s); Means of removal of water retained from interior of said debris basin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is cross section through a debris basin showing one embodiment of the present invention.

(2) FIG. 2 is cross section through a debris basin showing another embodiment of the present invention.

DETAILED DESCRIPTION

(3) Referring to FIG. 1, there is shown one embodiment of the present invention 100 in debris basin 101 where riser 103 is covered over with impermeable cover 104 closing off all openings 102 and trash rack 109 atop riser 103 such that there is no outflow through riser 103 via conduit 105. Embodiment 100 of the present invention disables gravity outflow from interior of debris basin 101 through conduit 105 such that outflow can only occur when level 106 of water 107 in debris basin 101 rises above invert level of spillway 108 atop dam 110, which may be fitted with trash rack 109 to capture floating debris. With embodiment 100 of the present invention, removal of retained water 107 from debris basin 101 requires other means, not shown. These may include pumping for transfer to higher elevations or siphonage for transfer to lower elevations.

(4) Embodiment 100 of the present invention captures all inflow to basin 101, both during both dry and wet weather times, until level 106 of water 107 reaches invert level of spillway 108. Stored water 107 may be removed by said means prior to a forecast wet-weather event to enable capture of inflowing water from that event. However, removal of water 107 from debris basin 101 prior to a wet weather event is not a necessity for functioning of debris basin 101 to entrap sediment and debris. This is because incoming sediment and debris will deposit and displace water 107 retained inside basin 101 regardless. Water 107 is pushed out of basin 101 over spillway 108 if basin 101 is full of water 107. Removal of retained water 107 from debris basin 101 by said means is only necessary to save stored water 107 and to restore capability of basin 101 to retain additional water.

(5) Referring to FIG. 2, there is shown another embodiment of the present invention 200 in debris basin 201 where openings 22 in riser 2023 and trash rack 209 atop riser 23 are provided to enable flow through riser 203 via conduit 205. Conduit 205 is fitted with flow control device 204 capable of shutting off flow through conduit 205 either completely or partially. Flow control device 204 may be located at a variety of locations in conduit 205, including at inlet, outlet, or anywhere in between, and can take a variety of shapes and forms including but not limited to lift gate, valve, or stop logs. Embodiment 200 of the present invention can fully shut off gravity outflow from interior of debris basin 201 through conduit 205 such that outflow can only occur when level 206 of water 207 in debris basin 201 rises above invert level of spillway 208 atop dam 210, which may be fitted with trash rack 209 to capture floating debris. With embodiment 200 of the present invention, removal of retained water 206 from debris basin 201 can be achieved by opening flow control device 204, either partially or fully, when desired.

(6) Embodiment 200 of the present invention provides operational flexibility for debris basin 201 with regards to timing and quantify of inflow water captured in debris basin 201. For example, the operator may decide to keep flow control device 204 open during dry weather flows if so desired and only capture wet weather flow, or vice versa. Embodiment 200 of the present invention also has the advantage of not requiring additional means for gravity flow of retained water 207 downstream.

(7) The present invention is susceptible to modifications and variations which may be introduced thereto without departing from the inventive concepts and the object of the invention. Various other means of restricting and/or shutting off flow in riser and conduit may be employed to accomplish the stated object of the present invention, which is to utilize debris for water retention in addition to entrapment of sediment and debris. Such means fall within the object of the present invention.

(8) While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is to be understood that the present invention is not to be limited to the disclosed arrangements, but is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all modifications and equivalent arrangements which are possible.