AU710185B3

AU710185B3 - Flood protection system

Info

Publication number: AU710185B3
Application number: AU41134/99A
Authority: AU
Inventors: Donald G Thompson
Original assignee: Hay Shona Grant Ms
Current assignee: Hay Shona Grant Ms
Priority date: 1999-07-26
Filing date: 1999-07-26
Publication date: 1999-09-16
Anticipated expiration: 2000-09-16

Description

AUSTRALIA

PATENTS ACT 1990

ORIGINAL

COMPLETE SPECIFICATION PETTY PATENT Invention Title: FLOOD PROTECTION SYSTEM Name of Applicant: MS SHONA GRANT HAY The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 FLOOD PROTECTION

SYSTEM

This invention relates to a flood protection system.

The flooding of waterways, and in particular, rivers, is a problem in both urban and rural areas. Known flood areas can be protected from flooding by the building of walls or levees, or improving drainage, which is generally adequate to cope with most situations. However, to allow for urban development land within known flood plains must be protected from the rare once 100 year flood event. This is achieved by zoning the land under Town Planning Ordances so that building restrictions or other restrictions apply in order to take into account the problems arising from flooding.

The Flood Plain of a waterway is any land inundated by the once in 100 year Average Return Internal (ARI) flood event along that waterway, determined in accordance with the provisions of the Water Act 1989.

In the descriptions hereafter relating to flood protection systems, processes or works, the term "flood plane" refers to any part of the overall Flood Plain along a waterway.

It can be noted that flood events that occur more frequently than the once in 100 year ARI event will only inundate portions of the Flood Plain, but the nature of the flood protection system herein aims to provide adequate flood protection against any flood event up to and including the once in 100 year ARI event, with a margin of additional height to cater for wavers and other irregularities of the water surface of the flood. This margin is termed "a Freeboad".

Protecting land from flooding is made more difficult if the flood plain includes a tributary, such as a creek or the \\melbfiles\home$\pau1ad\Keep\s"c \RAY- SHONA- FLOOD PROTECTION- PE7".doc 26/07/99 3 like, which runs into the river, and traverses the flood plain.

Any flood protection scheme must contain or control the surface water flow in the tributary, as well as providing protection from rising flood waters resulting from a major flood in the main waterway or river. Furthermore, the scheme shall achieve this objective without any significant detrimental effect to land and property elsewhere within or adjacent to the overall flood plain.

The present invention provides a flood protection system, which is intended to address the above situation.

The invention may be said to reside in a flood protection system for protecting a flood plain area which has a major waterway and a tributary running into the major waterway through the flood plain area, said system including; a barrier extending along the major waterway for separating the waterway from the flood plain area; a culvert through the barrier for allowing flow of the tributary through the culvert into the major waterway; and a flood gate on the culvert so that in the event of flooding of the major waterway, rising water, in the major waterway, and tending to flow back through the culvert, in an upstream direction of the tributary, causes closing of the flood gate, to shut of the flow of water from the flooding major waterway into the flood plain area.

In general, the flooding of the major waterway and possible flooding of the tributary, will occur at quite different times because of the different catchment areas for the major waterway and the tributary. In general the major waterway will have a large mainly rural catchment area \\melb files\homeS\paulad\Kep\speci\HAY SHONA- FLOOD PROTECTION- PETTY.doc 26/07/99 4 extending many miles upstream of the site of the flood protection scheme, whereas the tributary will have a small catchment area and it may be urbanised. Whin the concept of once in 100 year ARI flood event, the flash flooding, which is likely to cause the tributary to flood, will not cause flooding of the major waterway and, in turn, after heavy rains have fallen, which may cause large amounts of water to drain into the major waterway, the flooding of the major waterway in the vicinity of the system will not occur for several hours after the rain period because of the time taken for the flood wave to pass down the major waterway to the flood plain area. In the present invention, when the flood wave reaches the culvert, the flood gate will be closed by the water pressure in the culvert, caused by flow of water upstream through the culvert and tributary, to thereby effectively, seal off the flood plain area from the major waterway.

In one preferred embodiment of the invention, a pump station is included for pumping water from the tributary upstream of the flood gate into the culvert downstream of the flood gate to reduce the build-up of water flowing down the tributary and being blocked by the closed flood gate, so that in the event of a flood in the major water way, build-up of water from the tributary is pumped into the flooding major waterway by the pump station.

Preferably, the pump station includes a pump having an outlet which is directed towards the culvert opening which is closed when the flood gate moves to the closed position so that any debris, which may impair proper closing of the flood gate are shifted by the water exiting the pump to enable proper closing of the flood gate.

Preferably the culvert includes a grate upstream of the culvert opening for preventing large debris from entering the culvert.

\\melb-files\home$\paulad\Keep\speci \HAy- SHONA- FLOOD PROTECTION- PETTY.doc 26!0- 99 5 Preferably, the grate has a generally horizontal portion extending outwardly from the culvert and an inclined portion extending downwardly from the horizontal portion.

The invention may also be said to reside in a flood protection system for protecting a flood plain area which has a major waterway, a tributary running into the major waterway through the flood plain area, an embankment between the major waterway and the flood plain area, and a culvert extending through the embankment, said system including; an extension portion on the culvert forming an inlet chamber to the culvert; a flood gate coupled to the chamber for selectively opening or closing the culvert, such that water can flow along the tributary, through the culvert to the major waterway and, in the event of flooding of the major waterway, the flood gate is closed to prevent flood water from the major waterway from travelling through the culvert to the flood plain area thereby protecting the flood plain area from flooding.

A preferred embodiment of the invention will be described, by way of example, with reference to the accompanying drawings in which; Figure 1 is a plan view of a system and flood plain area embodying the invention; Figure 2 is a view along the line II II of Figure 1; Figure 3 is a view along the line III III of Figure 1; Figure 4 is a plan view of the part of the system shown in Figure 2; and Figure 5 is a view along the line V V of Figure 4.

\\melb-files~home$\Paulad\Kep\speci\Hy-SHONA- FLOOD PROTECTION- PETrY.doc 26/07199 6 With reference to Figure 1, a major waterway 10 such as a river or the like is shown flowing through a flood plain 12. The flood plain 12 also includes a tributary 14 which flows into the major waterway 10. Some land adjacent to the tributary would be flooded by the once in 100 year flood event along the major waterway, if no flood protection is in place. The major waterway 10 may be a river and the tributary 14 a creek or the like which drains into the river 10. The dotted line 16 shown in Figure 1 represents the boundary of the lands subjected to flooding by the once in 100 year ARI flood event in the major waterway 10. Thus all the flood plain 12 is subjected to flooding during the once in 100 year flood events whilst land being lower than that at the boundary of the flood plain, may be subjected to flooding more frequently. As a result the land is make, to some extend unusable for building or commercial purposes, or, at the very least, requiring restrictions on the use of the land 12 for commercial purposes, or for that matter, residential purposes.

The system according to the preferred embodiment of the invention, comprises a barrier which separates the flood plain area 12 from the major tributary 10. The barrier may be in the form of an embankment 20, which is more clearly shown in Figures 2 and 3. The embankment 20 is provided with a culvert 22 through which the tributary 14 can run so that water in the tributary 14 can flow to the major waterway 10. The embankment 20 may include a flood protection wall 24 for increasing the height of the embankment 20, and therefore, increase the amount of protection from rising water in the major waterway during flooding of the waterway The embankment 20 may also include a roadway 26, such as a freeway, which does not form part of the flood protection \\melb_files\homeS\paulad\Keep\spci\HAY- SHONA- FLOOD PROTECTION- PETTY.doc 26/07/99 7 scheme, but which may form part of the environment in which the present system is used.

The culvert 22 has an inlet end 30 and an outlet end 33.

The inlet end 30 is best shown in Figure 2 and comprises an extension portion 21 which forms a chamber 34. The chamber 34 has a footing 36 which is provided with an angled ledge 38. The chamber 34 also has a top wall or roof 23 which has an end flange 39. A flood gate 40 is provided in the chamber 34 and the flood gate 40 may be held open as shown in Figure 2 by springs or any suitable mechanism. The flood gate 40 is pivotally mounted to the flange 39 by any suitable mechanism.

Thus, in normal circumstances, water from the tributary 14 is able to flow through he chamber 34, the remainder of the culvert 22 and into the waterway 10. In the event of flooding of the waterway 10, the rising water in the waterway 10 will tend to back up through the culvert 22, thereby putting pressure on the flood gate 40, which will cause the flood gate 40 to close in the direction of arrow A in Figure 2 against the ledge 38 as shown by the solid line marked 40' in Figure 2. Thus, water is not able to flow through the culvert 22 back up into the tributary 14, thereby protecting the tributary 14 and the flood plain area 12a from flooding, not withstanding the flooding of the major waterway Water flowing down the tributary 14 must be collected somewhere and a collection basin 50 is provided for collection of that water. While some of the flood plain area 12 must be utilised for water collection from the tributary 14 in the event of closing of the flood gate the amount of land which is used for that collection is considerably less than what which would be flooded in a "100 year flood" if there is no flood protection system at all for preventing water from the main waterway 10 from \\melb-files\homeS\pau1ad\eep\spec.\HY SHONA- FLOOD PROTECTION- PETTY.doc 26/07/99 8 flowing into the flood plain area 12. Thus, flood plain 12a shown by the speckled area in Figure 1 is protected from flooding even in a "100 year flood" and therefore provides a flood plain area which is protected from flooding and which is therefore commercially and residentially useable, thereby increasing the value of the land 12a.

A pump station 60 (see Figure 4 and 5) may be provided alongside the chamber 34 for pumping water from the basin into the culvert 22 when the flood gate 40 is closed.

This reduces the amount of water retained in the basin The pump station 60 includes a pump 62 and the pump 62 has an outlet 64 which is directed towards the ledge 38 of the footing 36 so that any debris which may have collected on or about the ledge 38, and the inlet area of the chamber 34 will be washed away by water pumped from the pump thereby ensuring that the gate 40 can close properly against the ledge 38.

A grate 70 is provided upstream of the chamber 34 and includes a generally horizontal portion 72 and an incline portion 74. The grate 70 prevents large debris from entering the oulvert 22 and possibly blocking the culvert 22 and also from collecting in the vicinity of the ledge 38, which may otherwise prevent proper functioning of the flood gate 40. The inclined portion 74 of the grate enable debris, which is floating on the water level, to rise up the incline as water level in the tributary 14 increases and to generally collect on the horizontal portion 72. The bars forming the grate 70 are vertical at spacings to catch floating debris and allow the rising water to push this debris up onto the horizontal portion 72 of the grate 70. Thus, the grate is not blocked by buildup of debris and, in the event of rising water in the tributary 14, water can still flow through the grate 70 and the culvert 22. Build up of debris on the horizontal \\meibfiles\homeS\auad\Keep\spci\HAY- SHONA- FLOOD PROTECTION- PErTYrdoc 26/07/99 9 portion 72 can be removed by maintenance workers from time to time.

Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiments described by way of example hereinabove.

Dated this 26th day of July 1999 SHONA GRANT HAY By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia \\melb-files\hon$\Paulad\Keep\speci\Ay- SHONA- FLOOD PROTECTION- PETY.doc 26/07/99

Claims

2. The system of claim 1 wherein a pump station is included for pumping water from the tributary upstream of the flood gate into the culvert downstream of the flood gate to reduce the build-up of water flowing down the tributary and being blocked by the closed flood gate, so that in the event of a flood in the major water way, build- up of water from the tributary is pumped into the flooding major waterway by the pump station.
3. The system of claim 2 wherein the pump station includes a pump having an outlet which is directed towards the culvert opening which is closed when the flood gate moves to the closed position so that any debris, which may impair proper closing of the flood gate are shifted by the water exiting the pump to enable proper closing of the flood gate. \\melb-files\home$\paulad\Keep\speci\Ay SHONA- FLOOD PROTECTION- PETTY.doc 26/07/99