JP7812277B2 - Water supply system for rice terraces, construction method for water supply system for rice terraces and storage facility - Google Patents

Description

The present invention relates to a water supply system for rice terraces, a construction method for a water supply system for rice terraces, and a storage facility.

Traditionally, in rice terraces, where rice paddies are laid out in a stepped pattern on sloping land, water is taken from a water source such as a river and sent via a waterway from higher to lower rice terraces. This method tends to result in less water being sent to the more downstream cultivated areas, so one method involves installing a water supply system equipped with a water supply cistern and valves in each cultivated area to ensure a stable supply of water to all cultivated areas (see, for example, Patent Document 1).

Patent No. 4090674

However, even if water supply systems are installed in each cultivated area, a stable water supply cannot be achieved if a prolonged drought makes it difficult to secure water from rivers and other water sources. Furthermore, installing and operating water supply systems in each cultivated area is costly, and there are also limitations on the locations available for installing new water supply systems. For example, in order to efficiently distribute water from a river or other water source to the water supply system and then send it to the rice terraces without using pumps, the water supply system must be located upstream (at a higher position) from the rice terraces, between the river and the rice terraces.

On the other hand, rice terraces are often located in mountainous areas or in the surrounding landslide zones. Landslide zones usually have numerous landslide prevention facilities installed in them, such as horizontal wells and collection wells, to lower the groundwater level for the purpose of flood control. These landslide prevention facilities collect groundwater in collection wells and drain it quickly to prevent it from stagnating.

Landslide prevention equipment and water supply systems for rice terraces have different purposes and structures, and are also under the jurisdiction of different local government departments. For this reason, the people in charge of water supply systems for rice terraces do not handle landslide prevention equipment, and similarly, the people in charge of landslide prevention equipment do not handle water supply systems for rice terraces. As a result, even within close proximity to each other, one area is experiencing a water shortage, while the other needs to drain the water as quickly as possible.

The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide a water supply system for rice terraces that can efficiently secure irrigation water and distribute it to each cultivation area, as well as a method for constructing such a system.

To achieve the above-mentioned objective, the first invention is a water supply system for rice terraces, comprising a storage facility capable of collecting and storing groundwater, a water supply pipe capable of transporting water from the storage facility to the rice terraces, and a drainage pipe capable of draining water from the storage facility; the water supply pipe is equipped with a water stop valve, and by opening the water stop valve, the groundwater stored in the storage facility can be transported to the rice terraces via the water supply pipe; and when the amount of water stored in the storage facility reaches a predetermined level, water can be discharged from the drainage pipe.

In the first invention, groundwater that would otherwise be discharged as a landslide prevention measure is collected and stored in a storage facility, thereby ensuring efficient water supply. In particular, because groundwater is used, there are fewer restrictions on the placement of the storage facility due to its location relative to the river. In addition, by installing a stop valve in the water supply pipe and opening the stop valve when the stored groundwater is being transported, water can be distributed to each cultivated area of the rice terraces. Furthermore, by being able to drain the stored groundwater from the drainage pipe when the amount of stored groundwater exceeds a predetermined level, overflow from the storage facility can be prevented and the rise in the groundwater level can be suppressed.

The water supply system to the rice terraces may include a horizontal well placed underground, a collection well connected to a plurality of the horizontal wells, and a drainage channel connected to the collection well, wherein the horizontal well collects groundwater in the collection well, the drainage channel drains the groundwater from the collection well, and the storage facility is connected to the drainage channel and is capable of storing the groundwater discharged from the collection well.
This allows groundwater drained from existing landslide prevention facilities to be collected and stored in the storage facility.

A plurality of the collection wells may be connected to the storage facility.
This makes it possible to collect and store groundwater from a wide area of the landslide slope, making it easier to secure water. Also, even if the groundwater level in one area drops, water can still be collected in other areas as long as the groundwater level is high enough, making it less susceptible to fluctuations in groundwater level from place to place.

It is desirable that the water supply pipe be connected near the bottom of the storage facility, and the drainage pipe be connected at a predetermined height from the bottom of the storage facility.
This allows water to be pumped and discharged from the storage facility without using devices such as pumps.

The system may include a water temperature sensor that measures the water temperature in the rice terraces and a control unit that controls the opening and closing of the water stop valve, and the control unit may open the water stop valve when the water temperature in the rice terraces exceeds a predetermined range.The system may also include a heating device that can heat the water in the storage facility when the water temperature in the rice terraces falls below a predetermined level.
Since the temperature of groundwater is almost constant, this method makes it possible to adjust the water temperature in the rice terraces to an appropriate level if it becomes too high or too low, thereby preventing adverse effects of temperature on rice growth.

The second invention is a method for constructing a water supply system to rice terraces using existing landslide prevention equipment, the landslide prevention equipment comprising: horizontal wells placed underground; collection wells connected to a plurality of the horizontal wells and through which groundwater is collected by the horizontal wells; and a drainage channel connected to the collection well, the method comprising the steps of: installing a storage facility in the middle of the drainage channel or branching off from the drainage channel that can collect and store groundwater; installing a water supply pipe that can supply water from the storage facility to the rice terraces; installing a water stop valve in the water supply pipe that controls the amount of water supplied by the water supply pipe ; and installing a drainage pipe that can drain water from the storage facility.

The third invention is a method for constructing a water supply system to rice terraces using existing landslide prevention equipment, wherein the landslide prevention equipment comprises a horizontal well placed underground, a collection well connected to a plurality of the horizontal wells and through which groundwater is collected by the horizontal wells, and a drainage channel connected to the collection well, the method comprising the steps of: providing a weir in the collection well that can store a predetermined amount of water; installing a water supply pipe that can transport water from the collection well to the rice terraces ; and installing a stop valve in the water supply pipe that controls the amount of water transported by the water supply pipe; and connecting the drainage channel to the collection well so that the groundwater can be discharged into the drainage channel when the amount of groundwater stored in the collection well reaches a predetermined amount or more.

In the second invention, by adding a storage facility to existing landslide prevention equipment, groundwater drained from the landslide prevention equipment can be collected and stored in the storage facility. Furthermore, in the third invention, by modifying the collection well of the existing landslide prevention equipment, groundwater can be collected in the collection well and stored. In the second and third inventions, the stored groundwater can be conveyed by operating a water stop valve, making it easy to secure water and distribute it to each cultivated area of the rice terraces. Furthermore, by making it possible to drain the stored groundwater, the flood control effect of the landslide prevention equipment is not impaired.

The fourth invention is a storage facility comprising a storage section constructed using unreinforced precast concrete members, a groundwater inlet into the storage section, a water supply outlet located near the bottom of the storage section, a water stop valve capable of controlling the amount of water supplied from the water supply outlet, and a drain outlet that drains water when the amount of water stored in the storage section reaches a predetermined level.

In the fourth invention, the storage section can be easily constructed using unreinforced precast concrete members. Furthermore, groundwater is allowed to flow into the storage section through an inlet, where it is stored. The stored water can then be pumped out by controlling the amount of water flowing using a stop valve. Furthermore, by draining the water from a drain outlet when the amount of water in the storage section exceeds a predetermined level, overflow from the storage section can be prevented, and the rise in the groundwater level can be suppressed.

It is desirable to further include a heating device capable of heating the water in the reservoir.
This allows the water temperature in the reservoir to be adjusted to an appropriate temperature depending on the application.

The precast concrete member may be a hollow unit that is hexagonal in plan view, and the storage section may be constructed by combining a plurality of such units.
By using the units, the units can be easily transported and used to construct the storage area. In addition, by combining hexagonal hollow units, the storage area can be made stronger by forming a honeycomb structure.

The present invention provides a water supply system for rice terraces that can efficiently secure irrigation water and distribute it to each cultivation area, a construction method for a water supply system for rice terraces, and a construction method for a storage facility.

A diagram showing the area around terraced rice fields 5. A diagram showing storage facility 8 (8a). A diagram showing an example in which multiple collection wells 3 are connected to a storage facility 8. FIG. 10 is a diagram showing an example of a storage section 17a. A diagram showing a water supply system 7a to terraced rice fields 5. A diagram showing the collection well and storage facility 8b.

[First embodiment]
A first embodiment of the present invention will be described in detail below with reference to the drawings.
Figure 1 shows the area around the rice terraces 5, with Figure 1(a) showing the existing landslide prevention equipment 1 and Figure 1(b) showing the water supply system 7 to the rice terraces 5. Figure 2 shows the storage facility 8 (8a).

As shown in Figure 1(a), rice terraces 5 are located near landslide slope 6, on which existing landslide prevention equipment 1 has been installed. Landslide prevention equipment 1 consists of horizontal wells 2 located deeper than the groundwater level, collection wells 3 connected to multiple horizontal wells 2 and which collect groundwater via horizontal wells 2, and drainage channels 4 connected to collection wells 3.

The water supply system 7 to the rice terraces 5 is constructed using the existing landslide prevention equipment 1. As shown in Figures 1(b) and 2, the water supply system 7 is composed of a horizontal well 2, a collection well 3, drainage channels 4-1, 4-2, 4a-1, and 4a-2, storage facilities 8 and 8a, a water supply pipe 9, a water stop valve 10, a control unit 12, a drainage pipe 11, and a water temperature sensor 13.

The storage facility 8 is installed midway along the drainage channel 4 of the landslide prevention equipment 1. The storage facility 8a is installed between the drainage channels 4a-1 and 4a-2 that branch off from the collection well 3 (or drainage channel 4). In other words, both storage facilities 8 (8a) are located at a height below the collection well 3.

Storage facility 8 (8a) includes a storage section 17 with a roughly cylindrical horizontal cross section, and a lid 21 to prevent dust from entering storage section 17 and to prevent tampering. Storage section 17 is constructed from an impermeable material to prevent the stored water from seeping back into the ground. Storage section 17 is a manhole constructed using thin, unreinforced precast concrete members. Precast concrete members are manufactured by layering cement-based materials using, for example, 3D printing, and are installed in a neutralized state so as not to burden the surrounding environment. Constructing storage section 17 using 3D printed precast concrete members increases the surface area due to the unevenness of the layers, which is advantageous for carbon dioxide fixation and carbonation curing. Furthermore, the design can be designed to match the landscape of rice terraces 5.

The storage facility 8 (8a) is connected to the upstream drainage channel 4-1 (4a-1) and to the downstream drainage channel 4-2 (4a-2) via a drainage pipe 11 connected at a predetermined height from the bottom 15. The connection between the storage facility 8 (8a) and the drainage channel 4-1 (4a-1) forms the groundwater inlet 18 into the storage section 17. The connection between the storage facility 8 (8a) and the drainage channel 4-2 (4a-2) forms the drainage outlet 20 for water 16 from the storage section 17.

The drainage channel 4-1 on the inflow side and the drainage channel 4-2 on the outflow side to the storage facility 8 can be the drainage channel 4 of the landslide prevention facility 1. On the other hand, the drainage channel 4a-1 on the inflow side and the drainage channel 4a-2 on the outflow side to the storage facility 8a will be newly constructed. For this reason, for example, the drainage channel 4a-2 may be connected directly to a river or the like without being connected to the drainage channel 4 (drainage channel 4-2). The drainage channel 4-1 (4a-1) may be piped, for example, so that water can be conveyed even if there are elevation changes along the way. The drainage channel 4-2 (4a-2) may be piped, but may also be an open channel for maintenance purposes such as debris removal.

The water supply pipe 9 is connected near the bottom 15 of the storage facility 8 (8a). Multiple water supply pipes 9 may be connected to one storage facility 8 (8a). The connection between the storage facility 8 (8a) and the water supply pipe 9 forms the water supply outlet 19 for water 16 from the storage section 17. The water supply pipe 9 is provided with a water stop valve 10 to control the amount of water supplied from the water supply outlet 19. The water stop valve 10 may be a valve that can be opened and closed manually, but its opening and closing operation can also be controlled automatically. For example, a water level sensor controls the opening and closing of the water stop valve 10 according to the water level in the rice terrace 5. When the water level drops, the water stop valve 10 is opened to supply water, and when the water level rises, the water stop valve 10 is closed. Furthermore, as shown in the figure, the control unit 12 can control the opening and closing operation of the water stop valve 10 based on the measurement data of a water temperature sensor 13 installed in the rice terrace 5. Additionally, a separately installed rain gauge may be used to control the water stop valve 10 to close when rainfall exceeds a predetermined level. Such control of the water stop valve 10 can also be performed wirelessly.

In the water supply system 7, groundwater is collected in a collection well 3 by a horizontal well 2, and is then drained from the collection well 3 by a drainage channel 4-1 (4a-1). The groundwater drained by the drainage channel 4-1 (4a-1) flows into and is stored in a storage facility 8 (8a), as shown in Figure 2. In the storage facility 8 (8a), when the amount of water 16 stored in the storage section 17 exceeds the installation height of the drainage pipe 11, the water 16 is discharged from the drainage pipe 11. The height of the drainage channel 4-1 (4a-1) may also be higher than that of the drainage pipe 11.

In the water supply system 7, opening the stop valve 10 sends water 16 stored in the storage facility 8 (8a) via the water supply pipe 9 to each cultivated area of the rice terrace 5, which is located lower than the storage facility 8 (8a). The opening and closing of the stop valve 10 is typically controlled according to the water level in the rice terrace 5. When the water level drops, the stop valve 10 opens to supply water, and when the water level rises, the stop valve 10 closes. Furthermore, if the water temperature in the rice terrace 5 measured by the water temperature sensor 13 exceeds a predetermined range (above or below a predetermined temperature), the control unit 12 opens the stop valve 10 to supply water. Because the water 16 stored in the storage facilities 8, 8a is at a substantially constant temperature, the water temperature in the rice terrace 5 can be appropriately adjusted by supplying water from the storage facility 8, 8a. It is desirable for the storage facility 8 (8a) to be semi-underground in order to facilitate temperature control and thermal insulation of the stored water 16.

In the water supply system 7, a heating device (not shown) may be installed in the storage facilities 8, 8a. The heating device is preferably a device that utilizes natural energy such as sunlight or geothermal heat, and collects heat using, for example, a solar panel attached to the lid 21 of the storage section 17 or a heat pipe installed underground below the storage section 17. The heating device heats the water 16 in the storage facilities 8, 8a when the water temperature in the rice terraces 5 falls below a predetermined level. By supplying the heated water 16, the water temperature in the rice terraces 5 can be raised.

In this way, the water supply system 7 for rice terraces 5 of the first embodiment easily ensures water supply by collecting and storing groundwater drained from the existing landslide prevention equipment 1 in the storage facilities 8, 8a. Furthermore, a water stop valve 10 is provided on the water supply pipe 9 connected near the bottom 15 of the storage facilities 8, 8a. By opening the water stop valve 10 when transporting the stored water 16, water can be distributed to each cultivated area of the rice terraces 5. Because the water supply system 7 only requires the water stop valve 10 on the water supply pipe 9, costs are reduced compared to installing a water supply device in each cultivated area of the rice terraces 5. Furthermore, a drainage pipe 11 is provided at a predetermined height from the bottom 15 of the storage facilities 8, 8a. When the amount of stored water 16 exceeds the height of the drainage pipe 11, the water is discharged from the drainage pipe 11. This reliably prevents overflow from the storage facilities 8, 8a while maintaining the flood control effect of the landslide prevention equipment 1.

The water supply system 7 supplies water when the water temperature in the rice terraces 5 reaches a predetermined level or higher (at least above the groundwater temperature), thereby preventing the water temperature in the rice terraces 5 from rising. The water supply system 7 also supplies water when the water temperature in the rice terraces 5 falls below a predetermined level (for example, below the groundwater temperature), preventing the water temperature in the rice terraces 5 from dropping. If the water temperature in the rice terraces 5 falls below a predetermined level (for example, above the groundwater temperature), the water 16 in the storage facilities 8, 8a can be heated to prevent the water temperature in the rice terraces 5 from dropping. In this way, the water supply system 7 adjusts the water temperature in the rice terraces 5 to an appropriate level when it is too high or too low, preventing adverse effects of temperature on rice growth.

In the first embodiment, the storage portion 17 of the storage facility can be easily constructed by using unreinforced precast concrete members. Furthermore, by neutralizing the precast concrete members to a predetermined depth in advance through carbonation curing, the water 16 will not become alkaline even if it is in contact with the concrete for a long period of time in the storage portion 17. Therefore, when the water 16 is pumped, it will not have a negative impact on the growth of rice plants in the rice terraces 5, beneficial insects, or the surrounding ecosystem.

In the first embodiment, two storage facilities 8, 8a were installed for one collection well 3, but the water supply system only needs to include at least one collection well and one storage facility. Figure 3 is a diagram showing an example in which multiple collection wells 3 are connected to a storage facility 8. In the example shown in Figure 3, the storage facility 8 is connected to drainage channels 4-1 from three collection wells 3. This makes it possible to collect and store groundwater from a wide area of the landslide slope, making it easier to secure water. Furthermore, because many horizontal wells 2 are placed to cover a wide area, even if the groundwater level in one area drops, groundwater can be reliably collected in the storage facility 8 as long as the groundwater level in other areas is sufficient.

Furthermore, the construction method of the storage section 17 is not limited to the above. The storage section may be constructed, for example, using cast-in-place concrete, or by combining multiple units made of unreinforced precast concrete. Figure 4 shows an example of a storage section 17a constructed from multiple units 22. Figure 4(a) is a top view of the storage section 17a, and Figure 4(b) is a left-right view of the storage section 17a in Figure 4(a). The units 22 are hollow, unreinforced precast concrete members with a hexagonal horizontal cross section. The storage section 17a is constructed by stacking multiple units 22 in a honeycomb structure. In the storage section 17a, openings are formed where the units 22 overlap to allow water to move between adjacent units 22 in the horizontal and vertical directions. The strength of the storage section 17a can be increased by arranging the units 22 in a honeycomb structure.

The storage area can also be constructed by stacking multiple unreinforced precast concrete units so that their central axes are aligned. In this case, joining the upper and lower units can be made easier if they are designed to fit together like a slip joint. By using such small, lightweight units, the units can be easily transported to the site and installed, even when building the storage area in a narrow area of the rice terraces 5. The capacity of the storage area can also be increased by adding units to the upper tiers.

Second Embodiment
Another example of the present invention will be described below as a second embodiment. The second embodiment will be described by focusing on differences from the first embodiment, and similar components will be denoted by the same reference numerals in the drawings and will not be described again. The components described in each embodiment can be combined as needed.

Figure 5 shows the water supply system 7a to the rice terraces 5. Figure 6 shows the water collection well and storage facility 8b.

The water supply system 7a to the rice terraces 5 is constructed using the existing landslide prevention equipment 1 shown in Figure 1(a). As shown in Figures 5 and 6, the water supply system 7a is composed of a horizontal well 2, a drainage channel 4, a collection well/storage facility 8b, a water supply pipe 9, a water stop valve 10, a drainage pipe 11, etc. Note that the horizontal well 2 is not shown in Figure 6.

The collection well and storage facility 8b shown in Figures 5 and 6 is a modified version of the collection well 3 of the landslide prevention facility 1 shown in Figure 1(a), which does not originally have the function of storing water. The collection well 3 is modified into the collection well and storage facility 8b by installing a weir 14 at the connection point with the drainage channel 4, installing a water supply pipe 9 and a water stop valve 10, and connecting the drainage channel 4 and the collection well 3 with a drainage pipe 11. The connection point between the collection well and storage facility 8b and the horizontal well 2 serves as the groundwater inlet to the storage section 17. The connection point between the collection well and storage facility 8b and the drainage pipe 11 serves as the drainage outlet 20 for water 16 from the storage section 17.

The water supply pipe 9 is connected near the bottom 15 of the collection well and storage facility 8b. The connection between the collection well and storage facility 8b and the water supply pipe 9 forms a water supply outlet 19 for water 16 from the storage section 17. The water supply pipe 9 is provided with a water stop valve 10 for controlling the amount of water supplied from the water supply outlet 19. Multiple water supply pipes 9 may be connected to one collection well and storage facility 8b. The drainage pipe 11 is connected at a predetermined height from the bottom 15 of the collection well and storage facility 8b.

In the water supply system 7a, groundwater is collected and stored in the collection well/storage facility 8b via a horizontal well 2. When the amount of water 16 stored in the collection well/storage facility 8b exceeds the installation height of the drainage pipe 11, the water 16 is discharged from the drainage pipe 11 into the drainage channel 4.

In the water supply system 7a, opening the stop valve 10 causes water 16 stored in the collection well and storage facility 8b to be sent via the water supply pipe 9 to each cultivated area of the rice terrace 5. Normally, the stop valve 10 is opened and closed depending on the water level in the rice terrace 5, and when the water level drops, the stop valve 10 is opened to send water.

The water supply system 7a may be provided with a control unit 12 and a water temperature sensor 13 similar to those in the water supply system 7. The water collection and storage facility 8b may also be provided with a heating device (not shown).

In this way, the water supply system 7a for rice terraces 5 of the second embodiment easily secures water by storing groundwater collected by the existing landslide prevention equipment 1 in the collection well and storage facility 8b. Furthermore, a water stop valve 10 is provided on the water supply pipe 9 connected near the bottom 15 of the collection well and storage facility 8b. By opening the water stop valve 10 when transporting the stored water 16, water can be distributed to each cultivated area of the rice terraces 5. Furthermore, a drainage pipe 11 is provided at a predetermined height from the bottom 15 of the collection well and storage facility 8b. When the amount of stored water 16 reaches or exceeds the height of the drainage pipe 11, water is discharged from the drainage pipe 11. This reliably prevents overflow from the collection well and storage facility 8b while maintaining the flood control effect of the landslide prevention equipment 1.

The above describes preferred embodiments of the present invention with reference to the accompanying drawings, but the present invention is not limited to such examples. It is clear that those skilled in the art will be able to conceive of various modifications and alterations within the scope of the technical ideas disclosed in this application, and it is understood that these also naturally fall within the technical scope of the present invention.

1...Landslide prevention equipment 2...Horizontal well 3...Collection well 4, 4-1, 4-2, 4a-1, 4a-2...Drainage channel 5...Rice terraces 6...Landslide slope 7, 7a...Water supply system 8, 8a...Storage facility 8b...Collection well and storage facility 9...Water supply pipe 10...Stop valve 11...Drainage pipe 12...Control unit 13...Water temperature sensor 14...Weir 15...Bottom 16...Water 17...Storage unit 18...Inlet 19...Water supply outlet 20...Drainage outlet 21...Cover 22...Unit

Claims (11)

A water supply system for rice terraces,
A storage facility capable of collecting and storing groundwater;
a water supply pipe capable of supplying water from the storage facility to the rice terraces;
a drain pipe capable of discharging water from the storage facility;
Equipped with
The water supply pipe is provided with a water stop valve, and by opening the water stop valve, the groundwater stored in the storage facility can be supplied to the rice terraces through the water supply pipe.
A water supply system for rice terraces, characterized in that water can be discharged from the drainage pipe when the amount of water stored in the storage facility reaches a predetermined level. A horizontal well placed underground;
A collection well connected to a plurality of said horizontal wells;
a drainage channel connected to the collection well;
Equipped with
The horizontal well collects groundwater into the collection well;
The drainage channel drains groundwater from the collection well,
2. The water supply system for rice terraces according to claim 1, wherein the storage facility is connected to the drainage channel and is capable of storing groundwater discharged from the collection well. A water supply system for rice terraces as described in claim 2, characterized in that multiple collection wells are connected to the storage facility. The water supply pipe is connected to the vicinity of the bottom of the storage facility,
2. The water supply system for rice terraces according to claim 1, wherein the drainage pipe is connected to a predetermined height from the bottom of the storage facility. A water temperature sensor that measures the water temperature in the rice terraces,
A control unit that controls the opening and closing operation of the water stop valve;
Equipped with
2. The water supply system for rice terraces according to claim 1, wherein the control unit opens the water stop valve when the water temperature in the rice terraces exceeds a predetermined range. The water supply system for rice terraces described in claim 1 is characterized in that it is equipped with a heating device that can heat the water in the storage facility when the water temperature in the rice terraces falls below a predetermined level. A construction method for a water supply system to rice terraces using existing landslide prevention facilities,
The landslide prevention equipment includes:
A horizontal well placed underground;
a collection well connected to a plurality of the horizontal wells, through which groundwater is collected by the horizontal wells;
a drainage channel connected to the collection well;
Equipped with
A step of installing a storage facility capable of collecting and storing groundwater in the middle of the drainage channel or branching off from the drainage channel;
a step of installing a water supply pipe capable of supplying water from the storage facility to the rice terraces, and a water stop valve in the water supply pipe for controlling the amount of water supplied through the water supply pipe;
a step of installing a drainage pipe capable of discharging water from the storage facility;
A method for constructing a water supply system for rice terraces, comprising: A construction method for a water supply system to rice terraces using existing landslide prevention facilities,
The landslide prevention equipment includes:
A horizontal well placed underground;
a collection well connected to a plurality of the horizontal wells, through which groundwater is collected by the horizontal wells;
a drainage channel connected to the collection well;
Equipped with
providing a weir capable of storing a predetermined amount of water in the collecting well;
a step of installing a water supply pipe capable of supplying water from the water collection well to the rice terraces, and a water stop valve in the water supply pipe for controlling the amount of water supplied by the water supply pipe;
When the amount of groundwater stored in the collection well reaches a predetermined amount or more, connecting the drainage channel and the collection well so that the groundwater can be discharged to the drainage channel;
A method for constructing a water supply system for rice terraces, comprising: a reservoir constructed using unreinforced precast concrete members;
a groundwater inlet to the reservoir;
a water supply port provided near the bottom of the storage section;
a water stop valve capable of controlling the amount of water fed from the water feed port;
a drain outlet for draining water when the amount of water stored in the storage section reaches a predetermined amount;
A storage facility characterized by comprising: The storage facility described in claim 9, further comprising a heating device capable of heating the water in the storage section. The storage facility according to claim 9, characterized in that the precast concrete members are hollow units that are hexagonal in plan view, and the storage section is constructed by combining multiple such units.