JP2003227149A - River water reservoir facility outside of river course in flood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively use excessive flooded river water as living water in a flood. <P>SOLUTION: A pretreatment section 10 for removing foreign materials included in river water taken from a river 1 into the outside of a river course in a flood, is installed, and excessive river water in the flood sent from the pretreatment section 10 is temporarily reserved in a river water reservoir 20, fed to a downstream water purification facility while adjusting the flowing rate. Since the pretreatment section 10 is constituted of two storage reservoirs, the reservoir facility can flexibly cope with a large quantity of inflow in a flood or a condition of a few operation days, hence, both initial cost and maintenance cost can be reduced. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an out-of-channel storage facility for river water at the time of flood, in which the river water at the time of flood is subjected to pretreatment and stored in an underground cavern or the like, and water such as domestic water is stored as necessary. It relates to the extra river storage facility for river water at the time of flooding.

[0002]

As shown in FIG. 5, the stable water right of river water is set to a constant stable flow rate (drought flow rate) throughout the year, which exceeds the drought flow rate. The current situation is that the volume of flooded water during the flood is not utilized. If a large amount of river water, which was conventionally released during flooding, is stored in a storage facility provided outside the river channel with a specified capacity, new storage water in the storage facility can be used to create new domestic water, industrial water, or agricultural water. It can be expected to generate a new amount of water that can be used for water. However, the river water at the time of the flood is likely to be turbid. Therefore, if the water is stored as it is, sand or the like may flow into the storage facility and sediment, which may impair the storage volume and impair the water storage function. Therefore, it is preferable to provide a pretreatment device or facility for river water.

In this case, application of various purifying devices known as a pretreatment facility for river water, such as a sedimentation basin, a rapid filtration device, and a vortex type sand separation device, and a treatment facility combining a plurality of these devices is considered. To be However, since the inflow of river water at the time of flood is taken into consideration when installing these facilities, a large inflow method is used at the time of inflow, and if existing facilities such as sedimentation ponds are used, the facilities will become large-scale. There is a risk that it will not be cost effective. In addition, the operating equipment installed is not always in operation, resulting in poor operating efficiency. Therefore, installation of a large-scale and precise driving machine is not preferable in terms of capital investment.

Therefore, an object of the present invention is to eliminate the problems of the above-mentioned conventional techniques, and to make effective use of the temporarily stored surplus river water as water for daily life, etc. To provide facilities.

[0005]

In order to achieve the above object, the present invention provides a pretreatment unit for removing impurities contained in the river water taken during the flood, and a river water fed from the pretreatment unit. Is temporarily stored and the flow rate of the river water is adjusted, and the river water storage unit is capable of sending the water to the downstream water purification facility.

The pretreatment section has two pretreatment basins arranged in parallel, and the water supply system is switched to remove contaminants contained in the river water at a predetermined pretreatment basin and settle sand. Then, it is preferable to send the river water to the extra river storage facility.

At this time, it is preferable that the pretreatment basin is divided into a plurality of sections in the downflow direction, and the treatment level in each of the processing sections is increased successively in the downflow direction.

[0008] In the pretreatment pond, a sedimentation basket that can be taken out is sunk in each treatment section, and the sand that has settled and accumulated in the sedimentation basket by the sand settling process is discharged to the outside of the facility by the basket taking-out operation. It is preferable to do so.

The river water reservoir can be an underground cavern in bedrock or an existing reservoir or the like can be used.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a river water storage facility for flood water according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram schematically showing the overall configuration of the river water storage facility outside a river according to the present invention. Water intake facilities are provided for the rivers that are to be used for water storage operations, and the river water during floods is guided to the outside river storage facilities. Also in this out-of-river storage facility, the river flow rate that is the target of water storage operation is, as shown in FIG. 5, the flood flow rate that exceeds the set standard drought flow rate.

Referring to FIG. 1, in this embodiment, a water intake weir 2 is provided as a river water intake facility in a transverse direction of a river 1, and a reference drought flow rate that is invalidly discharged from a water intake 3 in front of the weir 2 during a flood or the like is shown. The excess river flow is taken into the river water inflow channel 4. In this embodiment, an open channel type is adopted for the river inflow channel 4 in order to prevent the pipe from being blocked by foreign matters at the time of flood. A river water pretreatment facility 10, which will be described later, is provided as a pretreatment unit in the route of the river water inflow channel 4. Further, downstream from the river water pretreatment facility 10, an outside river storage facility 20 having a predetermined water storage capacity is provided. As the storage facility 20, a closed storage facility using an underground cavity 21 as shown in each of FIGS.
An open storage facility using a reservoir 22 on the ground is assumed. The water is sent from the storage facility 20 to an existing water purification plant (not shown) by allowing it to flow naturally or by pumping it depending on the water level relationship of the set water channel. In the present embodiment, the water supply control unit 2 such as a control valve capable of adjusting the water supply amount for controlling the water supply from the storage facility 20.
5 are provided.

FIG. 2 is a configuration diagram showing an example of the configuration of the outside river storage facility 20. As shown in the figure, in this embodiment, an underground cavern (reservoir cavern) is used as the river storage facility 20.
The system and the reservoir system are proposed. FIG. 2A is a schematic configuration diagram showing the Ikeshita cavity method. In this example, the underground cavity 21 constructed in a solid rock is used as a storage facility outside the river. In this case, if the underground cavity 21 is installed under the water table around the bedrock, the water can be stored as a water-sealing facility, the facility can be simplified, and the surrounding spring water flowing into the underground cavity 21 is also one of the water sources. It can be used as a department. The shape of the underground cavity 21 is preferably a stable shape in consideration of the rock mass strength in which the extra-channel storage facility 20 is constructed, in addition to the illustrated kamaboko shape. Further, the inflow water channel 4 is a pipe tunnel that partially passes through the bedrock, but it is preferable that the inflow water channel 4 has a water channel gradient and a water channel cross section that prevent foreign substances from being clogged or settling in the tunnel.

FIG. 2B is a schematic diagram of the facility showing the reservoir system. In the figure, an example is shown in which the natural reservoir 22 is used as the extra-channel storage facility 20. Regarding this reservoir system, compensation problems and environmental problems in submerged areas due to storage are expected and suitable sites are decreasing, but there are many cases where there are many reservoirs 22 such as agricultural reservoirs in areas where water resources are insufficient. Many. If this type of agricultural water reservoir is diverted to the reservoir 22 of the present invention in urbanization, the reservoir system is also sufficiently effective in areas where water resources are insufficient.

By the way, when the river water at the time of flood is made to flow into the above-mentioned underground cavity 21 and the reservoir 22, the river water at the time of flood is muddy water accompanied by contaminants such as driftwood, sand, and mud. It is highly possible that sand and the like will be deposited early on the underground cavern as a storage facility or the bottom of the reservoir, impairing the water storage function. Therefore, in the present invention, the pretreatment facility 10 is installed in the river water inflow channel 4.

According to the present invention, in the case of storing turbid water in a river, coarse materials such as driftwood are prevented from flowing into the inflow channel 4 by a screen (not shown) installed at the intake 3 (FIG. 1). ing. Further, sand, mud and fine suspensions are treated in the river water pretreatment facility 10. River water pretreatment facility 1
The treatment level of 0 can be set according to the purpose, but here it is assumed that it is the river water quality during normal times when the water volume is small except during floods.

FIG. 3 (a) is a plan view showing a schematic structure of the river water pretreatment facility 10, and FIG. 3 (b) is a side view thereof. As shown in FIG. 3 (a), the river water pretreatment facility 10 has a basic structure of a 2-pond system in which pretreatment basins 11 for switching treatment systems are used in parallel. Therefore, each system of the river water pretreatment facility 10 is composed of ponds and water channels having exactly the same shape and size, and these are switched by the switching valve 12 provided on the inflow side. In the present embodiment, the pretreatment pond 11 has a reinforced concrete frame structure divided into a plurality of treatment sections in the downflow direction.

The structure of the facility will be described with reference to FIG. The branch inflow water channels 4A and 4B, which are branched into two by the switching valve 12 in the inflow water channel 4, continue to the pretreatment pond 11 at a predetermined gradient, and the sand accumulation pit 5 is provided immediately before the inflow port of the pretreatment pond 11. There is. A sand pump 6 capable of sucking up the sediment in the pit 5 is installed in the sand pool pit 5. Needless to say, the presence or absence of the pit 5 and the sand pump 6 and the scale and capacity of each facility can be appropriately set. In addition, although the reinforced concrete structure which comprises two independent pretreatment ponds 11 was independently constructed in FIG. 3 (a), one structure was partitioned by the central partition wall to construct two parallel ponds. You may.

The treatment zone of the pretreatment pond 11 is divided into a plurality of chambers having substantially the same capacity from the upstream side, and the primary treatment zone 12 and the secondary treatment zone 13 are continued from the upstream side so that the pretreatment level is successively increased for each zone. Is designed to. The final processing section 14 is provided on the outflow side. Further, an outflow channel 7 is connected to the outflow side of each pretreatment pond 11 and is led to an outside river storage facility 20 via a confluence section 8 (see FIG. 1). At this time, the closing valve 15 is provided in the route of the outflow water channel 7,
It is easy to clean the inside of the pretreatment pond 11 of the suspended system. The river water is sent to the outside river storage facility (not shown) after passing through the confluence portion 8. In this case, the water channel system may be a free flow system or a pumping system. Generally, when the outside river storage facility 20 is a reservoir 22, the reservoir 22
Sometimes pumps up to the level (Fig. 2 (b))
reference). Therefore, as shown in FIG. 3 (b), it is also preferable to install a water pump 9 to pump water. in this case,
Since the pumped water has been improved in quality through the pretreatment pond 11,
Pumping load can be made small enough.

FIG. 4 is a schematic perspective view schematically showing the structure of the pretreatment pond. In the pond, as shown in the figure, the primary treatment section 12 and the secondary treatment section 13 are arranged adjacent to each other in the flow-down direction, and the primary treatment section 12 and the secondary treatment section 13 are arranged.
A primary screen 16 is provided between the secondary processing section 13 and the secondary processing section 13, and a secondary screen 17 having a mesh smaller than that of the primary screen is provided on the downstream side of the secondary processing section 13. Furthermore, a sedimentation basket 30 having a bottom area slightly smaller than the floor area of each section is laid in each treatment section 12, 13 over a depth equal to or more than the effective water depth of the pond. The sedimentation basket 30 is a basket-like body having a side surface 31 surrounded by a mesh, and a bottom surface 32 is made of a stainless steel plate. Since this sedimentation basket 30 is sunk in each processing section 12, 13, when the river water passes through the mesh on the side surface of the sedimentation basket 30, the primary screen 1 having a relatively coarse mesh is formed.
Sand with relatively large grain size blocked by 6 is in primary treatment section 1
It is accumulated in the sedimentation basket 30 in the No. 2. Further, a relatively small-diameter sand component mixed with the river water flowing into the secondary treatment section 13 is captured by the secondary screen 17 and settles and deposits in the basket 30 in the secondary treatment section 13. At this time, the flood that occurs in the river will be drawn from the high water level within one to several days, so after the end of the flood, each sedimentation basket 30 is lifted outside the pond using a lifting device (not shown),
The sand S deposited inside can be removed (FIG. 4). As the lifting device, for example, a traveling crane that can travel along the pretreatment pond 11 is preferable.

In this way, the riverside storage facility 2 at the time of flood
The river water led to 0 can be temporarily stored by removing contaminants by pretreatment, and can be sent as water to a downstream water purification plant by adjusting the flow rate as necessary.

[0021]

[Effects of the Invention] Since the river water at the time of flood is stored outside the river channel through the pretreatment facility, it is possible to improve the water quality of the river water at the time of flood and store it on the assumption that it will be used as water. Therefore, the river water at the time of flood can be effectively used as water. In addition, since the pretreatment facility provided in the process has two ponds, it is possible to flexibly cope with large inflows during floods and conditions with few working days, and to reduce initial costs and maintenance costs. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a facility for storing river water outside a river during floods.

FIG. 2 is a schematic perspective view showing a configuration example (underground cavity) of a facility for storing river water outside a river during flood.

FIG. 3 is a schematic plan view and a side view showing a configuration example of a river water pretreatment facility.

FIG. 4 is a schematic perspective view showing a schematic configuration of a pretreatment pond.

FIG. 5 is a relationship diagram showing the relationship between stable river flow and actual river flow.

[Explanation of symbols]

1 river 3 water intake 4 river water inflow channels 7 waterways 10 River water pretreatment facility 12 Primary treatment area 13 Secondary treatment area 16 Primary screen 17 Secondary screen 20 Riverside storage facility 21 underground cavity 22 Reservoir 30 sedimentation basket

Claims (6)

[Claims] 1. A pretreatment unit for removing contaminants contained in river water taken during flooding, a river water sent from the pretreatment unit is temporarily stored, and the flow rate of the river water is adjusted to downstream. An extra-channel storage facility for river water during a flood characterized by comprising a river water storage unit that can send water to a water purification facility. 2. The pretreatment unit has a pretreatment pond having a parallel two-pond configuration, and the water supply system is switched to remove contaminants contained in the river water at a predetermined pretreatment pond and settle sand. The extra river storage facility according to claim 1, wherein the river water is treated and sent to the extra river storage facility. 3. The outside river storage facility according to claim 2, wherein the pretreatment pond is divided into a plurality of sections in the downflow direction, and the treatment level in each of the treatment sections is increased in sequence toward the downflow direction. . 4. In the pretreatment pond, a sedimentation basket that can be taken out is sunk in each treatment section, and the sand that has settled and accumulated in the sedimentation basket by the sand settling process is discharged to the outside of the facility by the operation of taking out the basket. The riverside storage facility according to claim 2, wherein the storage facility is located outside the river channel. 5. The out-of-river storage facility according to claim 1, wherein the river water storage portion is an underground cavern in bedrock. 6. The extra-channel storage facility according to claim 1, wherein an existing reservoir is used in the river water reservoir.