NZ545111A - Aquatic vegetation control apparatus and method - Google Patents

Abstract

Aquatic vegetation gathering apparatus for use in control of weeds or other vegetation in lakes and rivers and a method for controlling aquatic vegetation are disclosed. The apparatus has a floatable storage device (73), a pump to transport water and vegetation to the storage device through ducting (89), and a diver monitoring station (93). The storage device collects and stores vegetation while allowing the water to drain out. The ducting can be manipulated by a diver (90) to control the collection of vegetation into an inlet, while an attendant monitors the diver from the monitoring station. A mesh fence or enclosure (77) is used to encompass an area of water and define an isolation zone from which vegetation is to be collected.

Description

^ 5 Patents Form # 5 NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION AFTER PROVISIONALS # : 545111/549423 DATED : 03 February 2006/ 24 August 2006 TITLE : AQUATIC VEGETATION CONTROL APPARATUS AND METHOD We, AQUATEQ HOLDINGS LIMITED Address: 328 Bond Road, Te Awamutu, New Zealand, 3800 Nationality: A New Zealand company do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: [90988NZ._Cap_20070501_1014_PBA FEE CODE 1050 INTELLECTUAL PROPERTY OFFICE OF N.Z.

- I MAY 2007 RECEIVED FEELD OF THE INVENTION This invention relates to an aquatic vegetation control apparatus and method, and in particular, but not exclusively to an aquatic vegetation control apparatus and method for the 5 control of aquatic weeds in lakes.

BACKGROUND Many forms of vegetation grow in the water of lakes and many of them contribute to the local eco-system, for example by providing oxygen to the water. However, some forms of vegetation, particularly vegetation that is not native to a particular eco-system, can have 10 harmful effects. The most common, or visually apparent example of this, is aquatic vegetation that flourishes to the extent that the water becomes entangled with the vegetation and other life in the vicinity of the vegetation is suppressed. Other examples are vegetation or weeds that cause discolouration, or odour, or affect the taste of the water.

An example of such a problem is Lagarosiphon, or South African oxygen weed, which has in 15 recent times found its way into New Zealand lakes. This weed grows prolifically in New Zealand lakes and has been very difficult to control. Another example is the Hornwort weed which is prolific in many of the North Island of New Zealand hydro-electric dams and has clogged turbines and cost the electricity producers millions of dollars.

While these weeds can and have been controlled to some extent by the use of herbicides, 20 hand weeding or suction dredging, these methods are each limited in their effectiveness and have not been found to be effective for long term or cost effective use in the management of aquatic weeds. Diquat is an example of an herbicide that has been used extensively, but it is toxic to animal life at certain concentrations and it cannot be used extensively in lakes that are populated with fish or where people swim. Hand weeding can only be used where the 25 weed populations are low, and dredging can be expensive or can simply spread the problem around. It only takes a very small cutting of these weeds to begin a new colony. 190988NZ_CS0507/PA These weeds can be spread on boats and other craft when these are transported from one lake to another. This is particularly likely when the weeds are present in the water around boat ramps.

OBJECT It is therefore an object of the present invention to provide mi aquatic vegetation control device, apparatus or method which will at least go some way towards overcoming the above mentioned problems, or at least provide the public with a useful choice.

STATEMENTS OF THE INVENTION Accordingly, in a first aspect, the invention may broadly be said to consist in an aquatic 10 vegetation gathering apparatus having a floatable storage device, ducting adapted to transport water and aquatic vegetation to the storage device, a pumping unit adapted to pump water through the ducting, and a diver monitoring station, the floatable storage device being configured to collect and store vegetation and to allow water to drain out, the ducting being configured to allow manipulation by a diver to control the collection of vegetation into an 15 inlet end of the ducting, and the diver monitoring station being positioned to allow an attendant to supervise the operations of the diver.

Preferably a hold of the floatable storage device is covered by a mesh screen which is adapted to retain any collected vegetation but to allow water to exit the hold.

Preferably the floatable storage device is adapted such that it can be loaded onto a transporter 20 for removal of the storage device from a body of water.

Preferably the apparatus further includes a transporter adapted to remove the storage device from a body of water and to transport over land to a vegetation dumping site.

Preferably the apparatus further includes a mesh fence or enclosure adapted to encompass an area of water from which vegetation is to be collected.

Preferably the fence or enclosure extends at least one and a half metres below the surface of the water.

Preferably the pumping unit includes a venturi style pump. !90988NZ_CS0507/PA In a second aspect, the invention may broadly be said to consist in a method of controlling aquatic vegetation including the steps of; • isolating an area of water by establishing a mesh fence about the area, the fence extending from the water surface and toward the lake, river or sea bed, • providing a floating support station adapted to facilitate attendance for at least one diver, • using at least one diver to gather vegetation via a suction nozzle, • pumping any gathered vegetation into a floatable storage device, and removing the storage device from the isolated area of water and disposing of any 10 gathered vegetation.

Preferably the method further includes a step of liberating the vegetation from the lake, river or sea bed using a vegetation control device substantially as specified herein.

Preferably the method further includes a step of loading the storage device onto a land transporter to allow any gathered vegetation to be disposed of away from the body of water.

In a third aspect, the invention may broadly be said to consist in an aquatic vegetation control device having a lake bottom engagement means, a powerable vegetation liberating means and a suction nozzle, wherein the apparatus is capable of being manoeuvred along a lake or river bottom supported on the lake bottom engagement means and to present the vegetation liberating means to aquatic vegetation, and the suction nozzle is configured and 20 adapted to retrieve vegetation that is liberated into the water of the lake by the vegetation liberating means.

Preferably Ihe vegetation liberating means includes cutting means.

Preferably the cutting means is adapted to cut the stems of the vegetation.

Preferably the cutting means is configured and adapted to cut the stems of the vegetation at a 25 height above the lake or river bottom of between 50 and 300 millimetres (mm). 190988NZ_CS 0507/PA Optionally the vegetation liberating means is adapted to dislodge the roots of the vegetation from the lake bed.

Optionally the vegetation liberating means includes a tilling device.

Preferably the tilling device is a powerable tilling device.

Preferably the powerable tilling device includes rotatable tillers.

While the lake or river bottom engagement means can be wheels or tracks, preferably the lake bottom engagement means are skids or skis.

In a fourth aspect, the invention may broadly be said to consist in an aquatic vegetation control apparatus incorporating at least one aquatic vegetation control device as specified 10 herein.

Preferably the aquatic vegetation control apparatus further includes a pumping means adapted to pump water and vegetation from the suction nozzle.

Preferably the vegetation control apparatus further includes means to separate liberated vegetation from the water that is pumped through the suction nozzle.

Preferably the aquatic vegetation control apparatus further includes winching means adapted to move the aquatic vegetation control device along a lake bed.

In a fifth aspect, the invention may broadly be said to consist in a method of controlling aquatic vegetation including the steps of; • manoeuvring a vegetation control device along a lake bed, • liberating at least part of the vegetation growing from the lake bed using the vegetation control device, • collecting any liberated vegetation via a suction nozzle of the vegetation control device, and • removing the collected vegetation from the lake. 190988NZ_CS 0507/PA The invention may also broadly be said to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of the parts, elements or features, and where specific integers are mentioned herein which have known equivalents, such equivalents are 5 incorporated herein as if they were individually set forth.

DESCRIPTION Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in 10 which: FIGURE 1 is a side elevation view of a first example of an aquatic vegetation control apparatus in use, FIGURE 2 is a plan view of the first example of an aquatic vegetation control apparatus in use, FIGURE 3 is a side elevation view showing an aquatic vegetation control device of the aquatic vegetation control apparatus, FIGURE 4 is a partially cutaway plan view of the aquatic vegetation control device, FIGURE 5 is side elevation view of a second example of an aquatic vegetation control apparatus in use, and FIGURES 6A to 6C are side elevation views of a transporter adapted to remove a floatable storage device from a body of water.

FIRST EXAMPLE With reference to Figure 1, a first example of an aquatic vegetation control apparatus (11) is 25 shown comprising an aquatic vegetation control device (13), a pumping and storage vessel 190988NZ. CS 0507/PA (15) and a winching unit (17). The aquatic vegetation control apparatus (11) is shown in use in the water of a lake, and the vegetation control device (13) and the winching unit (17) are shown situated on the lake bed (19) while the pumping and storage vessel (15) is situated above the surface (21) of the water.

The winching unit (17) is used to drag the vegetation control device (13) along the lake bed (19) so that the vegetation control device (13) can cut or liberate aquatic vegetation (18) that is growing from the lake bed (19). The winching unit (17) can be moored to the lake bed or be mounted on a barge or other waterborne vessel. In this example the winching unit (17) is shown fixed to the lake bed using poles (20) that can be driven into the lake bed (19).

The pumping and storage vessel (15) is used to pump or extract the water from within or about the vegetation control device (13), and any released aquatic vegetation matter that is contained in this water, via a suction hose (22), and to store any collected aquatic vegetation matter for later disposal. In this example the pumping and storage vessel (15) comprises a barge (23), a pumping unit (25) and storage devices (27). While the storage devices (27) can 15 take many forms it is envisaged that bags made of a fine mesh material would be suitable. Such bags could allow the water to drain out freely, but depending on the mesh size could be adapted to retain vegetation matter as short as one or two millimetres in length.

The pumping and storage vessel (15) can also be used to provide a power source for the vegetation control device (13). While the vegetation control device (13) could be powered in 20 a number of ways, for example electrically or pneumatically, it is envisaged that a hydraulic power supply is preferable. In this example the pumping and storage vessel (15) is shown having a hydraulic pump (29) which can be used to power the vegetation control device (13) via a system of hydraulic lines (31). The hydraulic pump (29) can also be used to power the winching unit (17).

With reference to Figure 2, the vegetation control apparatus (11) is shown in plan view and in a configuration as it could be used when clearing vegetation from a lake bed. The apparatus (11) is shown situated within a mesh fence or screen (35) which forms a perimeter about the apparatus (11). 190988NZ_CS 0507/PA This mesh fence (35) is used to encompass an area of water and is designed to capture any fragments of vegetation that may inadvertently be liberated into the water as the apparatus (11) is used. The mesh fence ideally extends from the surface of the water to the lake bed, or at least from the surface to a depth of more than 1.5 metres. Floats can be used to hold the 5 top edge up, and weights can be used to hold the bottom edge down. Most of the vegetation in lakes does grow in water that is deeper than eight metres, so the mesh fence (35) need only be about this height at most. And any liberated vegetation tends to rise toward the surface meaning that it is not necessary for the fence (35) to extend all the way to the lake or river bed.

In this figure the winching unit (17) is shown having two drums (17a) and winch lines (17b), one connected to each side of the vegetation control device (13). This configuration is intended to keep the vegetation control device (13) moving in a straight line. However, it is envisaged that a single winch drum and winch line could be used, particularly if it was found necessary to steer the vegetation control device (13) separately.

With reference to Figures 3 and 4, the vegetation control device (13) is shown comprising a cutting means and a suction nozzle (41) which are both supported on a pair of skids (43), and a vegetation liberation device which in this example is in the form of a cutting means. In this example the cutting means comprises a sickle bar type cutter (45) which is driven by a hydraulic motor that can be situated within a housing (47).

The device (13) also includes two sets of guides. A first set of guides (51) support the suction nozzle (41), and a second set of guides (53) support the cutter (45) and the housing (47). Note: in figure 4 the first set of guides (51) and the suction nozzle (41) are omitted to allow the cutter (45) to be seen more clearly.

The device (13) can also include a handle bar system (55) which can be used by a diver to provide stability for the diver, and/or to help to control the device (13). For example hydraulic control valves can be mounted on the handle bar (55) so that a diver can control such things as the operation of the hydraulic motor for the cutter (45), or the hydraulic motor of the winching unit (17). 190988NZ_CS0507/PA In this example, the suction nozzle (41) is mounted on a frame member (57). The frame member (57) is attached to four first sliders (59) which are capable of moving up and down the first set of guides (51), and of being locked at a desired height using suitable fasteners, for example clip pins. This allows the height of the suction nozzle (41) above the skids (43) 5 to be adjustable, for example to suit differing weed heights.

Similarly the cutter (45) and its associated drive motor are mounted on second sliders (61) which are capable of moving up and down the second set of guides (53), and of being locked at a desired height using suitable fasteners, for example clip pins. This allows the height of the cutter (45) above the skids (43) to be adjustable, so that the cutting height can be 10 adjusted.

It can be seen in figure 3 that the winch lines (17b) pass through the bottom of the skids (43) and to the top side of the skids where they are attached. Such an attachment system can help to prevent the front of the skids (43) from digging into the lake bed as it is dragged along undulating terrain.

The suction nozzle (41) can be in the shape of a hood that is substantially pyramid shaped and having an outlet (63) at the apex of the pyramid shape. However, other nozzle shapes and outlet locations may also be used. The outlet (63) can be connected to the suction hose (22) of a pumping system as shown in figures 1 and 2. The leading edge of the nozzle (41) can also include guide arms (65) which are adapted to guide vegetation as it enters the nozzle 20 (41).

OPERATION In use, the vegetation control device (13) can be moved across the bed of a lake to remove vegetation from it. The vegetation can be drawn into the nozzle (41) by the suction of water being drawn towards the outlet (63) of the nozzle (41), and then the cutter (45) can liberate 25 the vegetation to allow it to be sucked through the nozzle (41) along with the water flow. This liberated vegetation can then be sucked away via the suction hose (22) and through the pumping unit (25) and then into the storage devices (27). Since the storage devices (27) are made from a porous or mesh like material, water can be separated and allowed to flow back 190988NZ _CS 0507/PA into the lake. The storage devices (27) can be removed from the pumping and storage vessel (15) and be taken away to allow the collected vegetation to be appropriately disposed of.

The fence (35) can be erected around the area in which the vegetation control device (13) is being used to allow any small fragments of vegetation that may escape the device (13) to be 5 captured. When the vegetation control device (13) has finished working in the area within the fence, the fence can be carefully gathered up in such a manner that any fragments of vegetation within it are captured. The fence can then be taken away to be cleaned and to carefully dispose of any vegetation that is captured by the fence.

SECOND EXAMPLE With reference to Figure 5, a second example of an aquatic vegetation control apparatus (71) is shown comprising floatable storage device (73) and a pumping vessel (75), each being situated within a perimeter fence (77). The fence (77) is used to encompasses an area of water in which the vegetation control apparatus (71) is to be operated and is used to contain 15 any fragments of vegetation that may be released during the operation of the vegetation control apparatus (71).

The fence (77) can be supported by floats (79) at its upper edge and ideally extends at least 1.5 metres below the surface of the water. Weights (81) can be used to hold the bottom edge down.

The pumping vessel (75) is provided with an engine (83) and a pump (85). A jet boat pump is suitable for this purpose. Water from the outlet of the pump (85) is directed into a venturi pump (87). The venturi pump (87) is used to increase the volume of water that is pumped by the apparatus (71). Water is drawn into the venturi pump via a suction duct (89). The suction duct (89) is used to collect aquatic vegetation from the lake or river in which the 25 vegetation control apparatus (71) is operating. Ideally the duct (89) is flexible and can be manoeuvred or controlled by a diver.

Vegetation can be introduced into the suction duct (89) by hand, as shown, or alternatively the vegetation can first be liberated using an aquatic vegetation device (13) as described with 190988NZ_CS 0507/PA reference to figures 1 to 4 above. Figure 5 shows a diver (90) gathering vegetation and introducing it into the inlet end of the suction duct (89). If the suction is sufficient, the weeds will be pulled out by their roots as the main body of the vegetation is drawn into the suction duct (89).

The floatable storage device (73) can be a barge like vessel into which the water from the venturi pump (87) is discharged. Preferably the storage device (73) floats higher at one end, allowing water to spill out of the opposite end. This can be achieved by providing the floatable storage device (73) with buoyancy chambers which can lift one end of the barge higher than the other. A mesh screen or net (90) can be used across the top of the storage 10 device (73) to help contain any collected vegetation while at the same time allow water to be separated from the vegetation.

The floatable storage device (73) and the pumping vessel (75) can be connected together using a rigid frame or struts (76). This allows the floatable storage device (73) and the pumping vessel (75) to be controlled as a single unit, and allows the distance between the 15 two to be fixed. The frame or struts (76) can be disconnected from the floatable storage device (73) or the pumping vessel (75) to allow the floatable storage device (73) to be towed away for emptying. • In the configuration as shown, the vegetation control apparatus (71) includes a first support station (91) on the pumping vessel (75), and a second support station (93) on the floatable 20 storage device (73). In each case the work station comprises a platform. From the first work station (91) the pump (85) can be managed, along with the management of an air supply cylinder (95) which can be supplied from a compressor driven by the engine (83).

From the second support station (93) the operation of the diver (90) can be monitored. For example an operator on the second work station (93) can communicate with the diver (90) 25 via a rope, using standard diving signals.

With reference a Figures 6A to 6C a transporter (97) is shown. The transporter (97) includes a truck cab and chassis and a tillable and translatable deck (99) and a tiltable guide rack (101). The transporter (97) can be used to remove the floatable storage device (73) 190988NZ_CS 0507/PA from the water, and to transport the storage device (73) over land to allow its contents to be emptied at a location away from the river or lake.

The transporter (97) can be backed up to the water's edge and then the tiltable and translatable deck (99) can be slid back toward and into the water. The tiltabie guide rack 5 (101) can be tilted if necessary using a hydraulic ram (103) to receive the floatable storage device (73). Preferably the tiltable guide rack (101) is provided with low friction pads, for example pads made from teflon or polyethylene plastics material to make it easier to winch the floatable storage device (73) up the guide rack (101). A winch (105) can be provided on the translatable deck (99) for this purpose.

Once the floatable storage device (73) is mounted onto the tiltable and translatable deck (99), mid locked in place, the deck (99) can be translated up onto the chassis of the transporter (97) to allow the storage device (73) to be carted away from the water. The contents of the storage device (73) can be dumped by opening a gate on the aft end of the device (73) and tilting the guide rack (101) using the hydraulic ram (103), and allowing the contents of the 15 storage device (73) to exit.

OPERATION The operation of the second example of an aquatic vegetation control apparatus (71) is as follows; • an area of water is isolated by establishing a mesh fence about the area, the fence 20 extending from the water surface and toward the lake, river or sea bed, • a floating support station adapted to facilitate attendance for at least one diver is provided, • at least one diver is used to gather vegetation through the inlet end of the suction duct (89), • any gathered vegetation is pumped into the floatable storage device (73), and • the storage device (73) is removed from the isolated area of water and any gathered vegetation is disposed of. 190988NZ_CS 0507/PA The method can further include a step of liberating the vegetation from the lake, river or sea bed using a vegetation control device substantially as specified herein.

As noted above, to empty the storage device (73) it can be loaded onto a land transporter (97) to allow any gathered vegetation to be disposed of away from the area of water.

Water spilling out the back end of the storage device (73) can tend to gently move the combined storage device (73) and pumping vessel (75) through the water as the diver (90) moves along the surface of the lake or river bed while gathering vegetation.

VARIATIONS In a further variation the aquatic vegetation control device can include tilling means, in place of or in addition to, the cutting means shown in figures 3 and 4 above. The tilling means could for example take the form of a roto-tilling means that is adapted to liberate the vegetation from a lake bed by essentially digging it out by its roots and allowing the vegetation to be sucked into the suction nozzle (41).

While the cutting means in the above example is a sickle bar cutter, it is envisaged that other types of cutting means could be used, for example rotary cutters of the type that are used to cut grass in pastoral farming applications.

In the example described above the aquatic vegetation control device (13) is shown being winched along the lake bed, however in an alternative embodiment, the aquatic vegetation 20 control device (13) could be dragged along behind a vessel, or be self propelled.

In the example described above the aquatic vegetation control device (13) is shown having skids or skis, however it is envisaged that it could have tracks or wheels.

In the example described above the aquatic vegetation control apparatus (11) is shown and described having the pumping and storage vessel (15) separate to the winching unit (17). 25 However, it is envisaged that in an alternative configuration the two items could be combined as one. 190988NZ_CS 0507/PA Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof.

DEFINITIONS Throughout this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.

ADVANTAGES Thus it can be seen that at least the preferred form of the invention provides an aquatic 10 vegetation control device, apparatus or method which is capable of removing large quantities of vegetation from a lake bed and of capturing the greater part of any removed vegetation for retrieval. 190988NZ_CS 0507/PA Received at IPONZ on 3 June 2008

Claims (11)

1. An aquatic vegetation gathering apparatus having a floatable storage device, ducting adapted to transport water and aquatic vegetation to the storage device, a pumping unit adapted to pump water through the ducting, and a diver monitoring station, the floatable storage device being configured to facilitate the collection and storage of vegetation and to allow water to drain out, the ducting being configured to allow manipulation by a diver to control the collection of vegetation into an inlet end of the ducting, and the diver monitoring station being positioned to allow an attendant to supervise the operations of the diver, the apparatus being further characterised in that includes a mesh fence or enclosure adapted to encompass an area of water from which vegetation is to be collected.

2. An aquatic vegetation gathering apparatus as claimed in claim 1, wherein a hold of the floatable storage device is covered by a mesh screen which is adapted to retain any collected vegetation but to allow water to exit the hold.

3. An aquatic vegetation gathering apparatus as claimed in either claim 1 or claim 2, wherein the floatable storage device is adapted such that it can be loaded onto a transporter for removal of the storage device from a body of water.

4. An aquatic vegetation gathering apparatus as claimed in any one of the preceding claims, wherein the apparatus further includes a transporter adapted to remove the storage device from a body of water and to transport over land to a vegetation dumping site.

5. An aquatic vegetation gathering apparatus as claimed in claim 4, wherein the fence or enclosure extends at least one and a half metres below the surface of the water.

6. An aquatic vegetation gathering apparatus as claimed in any one of the preceding claims, wherein the pumping unit includes a venturi style pump.

7. An aquatic vegetation gathering apparatus substantially as described herein, with reference to Figure 5 of the accompanying drawings.

8. A method of controlling aquatic vegetation including the steps of; 190988NZ_CS. as amended.doc/PA Received at IPONZ on 3 June 2008 -16- • isolating an area of water by establishing a mesh fence about the area, the fence extending from the water surface and toward the take, river or sea bed, • providing a floating support station adapted to facilitate attendance for at least one diver, • using at least one diver to gather vegetation via a suction nozzle, • pumping any gathered vegetation into a floatable storage device, and • removing the storage device from the isolated area of water and disposing of any gathered vegetation.

9. A method of controlling aquatic vegetation as claimed in claim 8, wherein the method further includes a step of liberating the vegetation from the lake, river or sea bed using an aquatic vegetation gathering apparatus substantially as claimed herein.

10. A method of controlling aquatic vegetation as claimed in any one of claims 8 or 9, wherein the method further includes a step of loading the storage device onto a land transporter to allow any gathered vegetation to be disposed of away from the body of water.

11. A method of controlling aquatic vegetation substantially as described herein, with reference to Figure 5 of the accompanying drawings. PIPERS Attorneys for: Aquateq Holdings Limited !90988NZ_CS. as amended.doc/PA