JP2004211403A - Fish way facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a stable fish way water volume and facilitate maintenance of a fish way facility with a simple constitution by separately providing an intake part from the fish way outlet. <P>SOLUTION: A fish way entrance is installed at the downstream end of a fish way water way 2 belonging to a dam, and the intake part 3 is installed at the upstream end of the fish way water way 2. River water is pumped up by a pump and supplied from a column pipe 9 to the intake part 3. An overflow wall 17 is erected in the downstream side of the intake part 3 in a condition that the overflow wall is inclined to the downstream side and a notch 18 is formed at the one side of the upper end of the overflow wall 17. The fish way outlet 19 is provided at the falling position of the stream over the notch 18, and fish dropped to the fish way outlet 19 is guided to the dam lake through an induction pipe 21. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fishway facility constructed on a dam.
[0002]
[Prior art]
Fish (including crustaceans) run up in favor of fishways with stable water volumes, but the water volume in the fishways tends to fluctuate depending on the water level of the dam lake, which is the source of water intake. Conventionally, a technique has been proposed in which a height-adjustable partition wall is provided in an intake port of a fishway waterway or in the middle of a fishway to stabilize the fishway water volume. In Patent Document 1 (see paragraph number 0013), an intake port is provided in a movable water path that can move up and down, the movable water path is floated by a float against the urging force of a spring cylinder, and the height of the intake port is set at the water level of the dam lake. A technique for following changes is described.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-115243
[Problems to be solved by the invention]
However, according to the conventional fishway equipment, since the water quantity of the fishway is adjusted by the movable part, the configuration of the fishway becomes complicated, and there is a problem that the equipment cost is high. In addition, since the intake of the fishway canal also functions as an exit for fish (fishway exit), the intake had to be provided facing the dam lake. For this reason, if the intake is submerged at the time of rising water, there is a problem that driftwood and boulders in the turbid flow flow into the fishway or damage the intake.
Although measures have been taken to install protective fences at the intake, there was a problem that garbage easily collected and maintenance was troublesome.
[0005]
An object of the present invention is to solve the above-mentioned problems and to provide a fishway facility which can obtain a stable fishway water volume with a simple configuration and is easy to maintain.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the fishway equipment of the present invention includes a fishway waterway attached to a dam, a fishway inlet is provided at a downstream end of the fishway waterway, an intake section is provided at an upstream end of the fishway waterway, and a water intake section is provided. Connect the water supply channel, establish an overflow wall downstream from the intake section in the fishway waterway, set up a fishway exit at the point of falling water flowing over the overflow wall in the fishway waterway, and transfer fish to the dam lake at the fishway exit. It is characterized by connecting a guiding channel for guiding.
[0007]
Here, the fishway waterway is not limited to a specific structure, but may be, for example, a waterway having a step-type slope structure, a waterway having a track-type spiral structure, a waterway having a bridge-type switchback structure, or the like. The material of the fishway channel is not particularly limited, and concrete, resin, wood, and the like can be exemplified. In the case of concrete, it is possible to construct a fishway waterway by a cast-in-place method, but it is preferable to use a precast concrete fishway block for at least a part of the waterway in that the construction period can be shortened and equipment costs can be reduced. .
[0008]
ADVANTAGE OF THE INVENTION According to this invention, the water intake part of a fishway waterway is provided separately from the fishway outlet (fish exit), and a stable quantity of water is always supplied to the water intake part from a water supply channel. For this reason, it is not necessary to expose the water intake section to the dam lake. For example, installing the water intake section at a position higher than the full water level of the dam (dam upper limit water level of the dam) to avoid driftwood and boulders at the time of water increase. Can be. To supply water to the intake section, a water supply channel may be laid from the upstream water area of the dam, but it is preferable to connect the water supply channel to a pump for pumping water from the river in that facility costs can be reduced.
[0009]
It is desirable to provide a means for efficiently guiding fish to the exit of the fishway on the overflow wall. For example, the overflow wall may be inclined at the upper side to the downstream side, a notch may be formed at the upper end of the overflow wall, and a fishway outlet may be provided at a place where the flowing water falls beyond the notch. In this case, since the separation wall is formed by the overflow wall, the fish are prevented from going upstream by the separation flow, guided to the notch side where the amount of flowing water is abundant, and flown into the overflow water having a rapid flow velocity beyond the notch. , Fall into the fishway exit. In addition, since fishes prefer to flow straight water, they are preferably provided with a flow straightening member such as a perforated plate or a wire mesh in the water intake portion to rectify turbulence in the water intake portion in advance.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the fishway equipment of this embodiment includes a concrete fishway waterway 2 attached to a dam 1 on a river bank downstream of the dam 1. At the upstream end of the fishway waterway 2, there is provided a water intake section 3 for taking in water from the river, and a gentle flow section 4 having a gentle gradient (about 1/20 to 1/30) downstream of the water intake section 3 in the fishway waterway 2 is provided. Is provided. A relatively steep (about 1/3 to 1/15, most preferably about 1/10) rapid flow section 5 is provided downstream of the gentle flow section 4 in the fishway waterway 2, and at the downstream end of the rapid flow section 5. A fishway entrance 6 serving as an entrance for fish is provided so as to open to the riverbed downstream of the dam 1.
[0011]
The water intake section 3 is installed on the upper surface of the dam 1 so as to be higher than the full water level of the dam 1. The water intake unit 3 is connected to a water pump 9 for drawing water from the dam lake 8 to the water intake unit 3 and a spill discharge pipe 10 for returning surplus water from the water intake unit 3 to the dam lake 8. The pumping pipe 9 functions as a water supply channel to the water intake unit 3, and the lower end thereof is connected to a pump 11 for pumping water from the dam lake 8. The pump 11 is installed so as to float on the water surface of the dam lake 8 by the float 12. The pump 13 and the spill discharge pipe 10 are provided with valves 13 and 14 for adjusting the flow rate, respectively.
[0012]
As shown in FIGS. 2 to 5, a rectifying member 16 made of a perforated plate is provided inside the water intake unit 3, and turbulent water immediately after being pumped to the water intake unit 3 is rectified by the rectification member 16. On the downstream side of the straightening member 16 in the fishway waterway 2, an overflow wall 17 is erected at the boundary between the water intake section 3 and the gentle flow section 4 with its upper side inclined to the downstream side. 17 and flows into the gentle flow portion 4 as a separated flow (water flow separated from the downstream side wall surface of the overflow wall 17). A notch 18 is formed on one side of the upper end of the overflow wall 17, and a fishway exit 19 is provided at a corner of the floor of the gentle flow portion 4 at a place where the flowing water falls beyond the notch 18. Then, the fish that have run up to the vicinity of the overflow wall 17 fall into the fishway exit 19 together with the rapid water from the notch 18.
[0013]
In consideration of the run-up environment preferred by fish, the amount of water in the water intake section 3 is adjusted so that a separated flow having a depth of about 2 cm is formed above the overflow wall 17 by the valves of the pumping pipe 9 and the spill discharge pipe 10. It is preferable to adjust at 13 and 14. The notch 18 is desirably formed with a depth of about 2 cm so that a separation flow of about 4 cm in depth is formed in the notch 18.
Also, the width of the notch 18 is set to be slightly larger than the opening width of the fishway exit 19 so that most of the overflow from the notch 18 falls to the fishway exit 19 and the remaining part falls on the floor of the gentle flow part 4. Good to do.
[0014]
A guidance channel 22 (see FIG. 1) is connected to the fishway exit 19 via a guidance tube 21. The guide channel 22 is provided on the dam 1 in a gentle slope, and guides fish dropped from the fishway exit 19 to the dam lake 8 from the upstream side of the dam 1. The downstream end of the guide channel 22 may be higher or lower than the water surface of the dam lake 8, but the lower end is preferable because it is less likely to be clogged with garbage. When the headway between the fishway exit 19 and the water surface of the dam lake 8 is large, the guide channel 22 may be configured in a stepped manner, or a pond where fishes rest may be provided in the guide channel 22. It is also possible to provide the guiding water channel 22 so as to bypass the dam 1 from the fishway exit 19 and extend to the dam lake 8 through the river bank.
[0015]
The gentle flow portion 4 is divided into two in the width direction by a partition wall 23 extending in the flowing water direction, and includes a narrow water flow region 4a for passing overflow water to the rapid flow portion 5 and a water storage region 4b for temporarily storing overflow water. ing. In the water storage area 4b, a floor surface of a portion corresponding to the partition wall 23 is formed horizontally (see FIG. 5), and a rest pool of fish with a gentle flow is formed in this portion. A drain hole 24 is provided at a floor corner of the water storage area 4b, and a drain amount adjusting valve 26 (see FIG. 3) is provided on a drain pipe 25 connected thereto. Then, by adjusting the amount of drainage, the amount of water flowing out from the upstream end of the partition wall 23 to the water passage area 4a side can be adjusted, and a substantially constant amount of gentle flowing water can be stored in the water storage area 4b. Coarse stones 27 are sparsely laid on the floor surfaces of the gentle flow portion 4 and the rapid flow portion 5.
[0016]
In the fishway equipment configured as described above, fish enter the fishway waterway 2 from the fishway entrance 6, go up the rapid flow portion 5, and reach the gentle flow portion 4. Since the gentle flow part 4 is provided with the water storage area 4b having a gentle flow velocity, the fishes rest here for a while, and then resume the ascent to the overflow wall 17. However, since the overflow wall 17 is inclined to the downstream side and forms a separated flow with a hollow behind, the fish are prevented from going up by the separated flow, and the notch 18 is searched for a run-up path with abundant flow. Move to the side. Then, an attempt is made to run up the overflow of the notch 18, but the water is washed away by the overflow water having a rapid flow rate and falls into the fishway exit 19. Thereafter, the fish reach the dam lake 8 through the guide pipe 21 and the guide channel 22.
[0017]
Therefore, the fishway equipment of this embodiment has a simple waterway structure in which the water intake section 3 and the fishway exit 19 are separated, and can efficiently fish upward from the downstream side of the dam 1 to the upstream side. Moreover, by separating the water intake section 3 from the fishway exit 19, the water intake section 3 can be installed at a position higher than the full water level of the dam 1. Therefore, the fishway water volume can be constantly stabilized by the water supply from the pump 11 without being affected by the water level change of the dam lake 8. In addition, since the water intake section 3 does not submerge even when the water is increased, there is no risk that driftwood or boulders will flow into the fishway waterway 2 or damage the water intake section 3, and a protective fence becomes unnecessary, and the trouble of removing garbage is eliminated. It can be omitted.
[0018]
6 to 8 show modified examples of the fishway waterway. The fishway channel 31 is composed of a water intake section 32, a gentle flow section 33, a horizontal section 34, and a step section 35, and a fishway entrance (not shown) is provided at a downstream end of the step section 35. A drain pipe 36 is provided upright on the bottom wall of the water intake section 32 on the upstream side of the flow regulating member 16 so as to be adjustable in height. A partition 37 is provided upright at a boundary between the gentle flow portion 33 and the horizontal portion 34, and a notch 38 is formed on one side of an upper end thereof. The roadbed of the gentle flow portion 33 forms the lowest slope near the notch 38, and the flowing water that has passed the overflow wall 17 flows down toward the notch 38. A stone or brick 39 having a flat surface is laid on the roadbed near the fishway exit 19 so that fishes can easily approach the fishbed.
[0019]
The horizontal part 34 forms a rest pool for fish, and stones 41 for rectifying turbulence are deposited on the roadbed. The stairs 35 are formed by connecting a large number of fishway blocks 42 made of precast concrete in a step-like manner. A rectifying stone 41 is laid at the bottom of each block 42, and a notch 44 is formed on one side of the upper end of the partition 43. ing. The overflow water depth of the partition 43 is about 4-5 cm, the flow velocity is about 0.4-0.6 m / s, the overflow water depth of the notch 44 is about 8-9 cm, and the flow velocity is about 0.8-1.2 m / s. preferable. Since the drainage pipe 36 is provided in the water intake part 32 so that the height can be adjusted, the flow rate of each part of the fishway waterway 31 can be adjusted by adjusting the amount of water in the water intake part 32 by combining the drainage pipe 36 and the valves 13 and 14. The flow rate can be easily fine-tuned. The width of the staircase portion 35 is set to be narrower than the horizontal portion 34 or the like so as to correspond to a decrease in the flow rate from the fishway exit 19. Other configurations and operational effects are the same as those of the fishway waterway 2.
[0020]
Note that the present invention is not limited to the above-described embodiment, and may be embodied with appropriate modifications without departing from the spirit of the invention, for example, as described below.
(1) Separate the intake section of the fishway waterway from the dam and install it on the river bank downstream or upstream from the dam.
(2) Pump water from the river downstream of the dam and supply it to the intake section.
(3) Submerge the submersible pump in the dam lake or in the river downstream from the dam, and pump it to the intake section.
(4) The pump must be fixed on the dam.
[0021]
【The invention's effect】
As described in detail above, according to the fishway equipment according to the present invention, the water intake section is provided separately from the fishway outlet, so that a simple configuration can provide a stable fishway water volume and facilitate maintenance. It works.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of a fishway facility according to the present invention.
FIG. 2 is a perspective view showing a fishway waterway of the facility.
FIG. 3 is a plan view of the waterway.
FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;
FIG. 5 is a sectional view taken along line VV of FIG. 3;
FIG. 6 is a perspective view showing a modified example of the fishway waterway.
FIG. 7 is a plan view of the waterway.
FIG. 8 is a cross-sectional view of the waterway.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Dam 2 Fishway waterway 3 Intake section 4 Slow section 5 Rapid flow section 6 Rapid way section 6 Fishway entrance 8 Dam lake 9 Pumping pipe 11 Pump 16 Straightening member 17 Overflow wall 18 Notch 19 Fishway exit 22 Guideway 31 Fishway waterway 32 Water intake section 33 Low flow Part 34 Horizontal part 35 Stair part 42 Fishway block

Claims (5)

A fishway channel attached to the dam is provided, a fishway entrance is provided at the downstream end of the fishway channel, an intake section is provided at the upstream end of the fishway channel, a water supply channel is connected to the intake section, and the fishway channel extends downstream from the intake section in the fishway channel. A fishway facility comprising a standing waterwall, a fishway exit at a location where water flows over the overflow wall in the fishway channel, and a fishway exit connected to a guiding channel for guiding fish to a dam lake. The fishway equipment according to claim 1, wherein the water intake section is installed at a position higher than a full water level of the dam. The fishway equipment according to claim 1 or 2, wherein the water supply channel is connected to a pump for pumping water from a river. The upper side of the overflow wall is inclined to the downstream side, a notch is formed at the upper end of the overflow wall, and a fishway outlet is provided at a falling point of flowing water beyond the notch. Fishway equipment as described. The fishway equipment according to any one of claims 1 to 4, wherein a rectifying member is provided in the water intake unit.

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