Weir (Thomson Weir / V notch sharp crested weir)

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Parameter to be measured:

Discharge of open channels

Method:

Equipment:

  1. Weir (concrete, wood, metal)
  2. V notch weir plate (stainless steel)
  3. Water Level Sensor:
    1. Bubble Sensor
    2. Shaft Encoder
    3. Radar Sensor
    4. Pressure Sensor
    5. (Capacity Sensor)

Construction:

Design of the weir‎
  1. Planning: Before you can build a weir, you need permissions from different institutions. In my case (Bavaria, Germany) I needed permissions of following people:
    1. Owner
    2. Fishing rights
    3. District office
    4. Nature conversation agency
    5. Water right agency
      It took quite a while (around three month) although the adminstration was helpful. I heard that it can take much longer. So start the administration stuff as soon as possible. Especially if the river falls under the nature conservaty right. possible.
  2. Accumulation and Drainage of the water: Before you can start the construction of the weir, you have to accumulate the water in front of the construction site and then you have to draine the water around or over the weir.
    Accumulation and Drainage of the water
    If you have electricity you can use pumps (dirt water pumps). But be sure that the pumps can runover night, because the concrete has to dry at least twelve hours. Use at least two pumps, because it is a little tricky that all the water is pump away and that the pumps are not running dry. One big pump for most of the water and the other for the adjustment. In the case you don't have electricity, you can build one or two small temporary dams and then use a pipe to drain the river water over the weir. I think it is saver, because you don't have to relay on the pumps. I would suggest that you use a 12 V pump to get the water away which is leaking through the dam. You can run the pump with a battery.

Advantages:

Disadvantages:

What to watch out for:

Problems/Questions:

Links

Projects that used the above equipment:


Other related web sites:


References