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A well promises a cheap solution to obtain water for watering and for many other purposes. If the water column falls, there will be no funding. We reveal reasons and an associated solution.
In a nutshell
- if the water level drops, the pump can no longer pump water out of the well
- if less water flows in than the pump extracts, the equilibrium is disturbed and the water column falls
- only a sufficiently high water level provides the suction power of the pump with sufficient support for constant delivery
- various causes of dropping of the water column
- require different countermeasures
water column explained
A well construction usually consists of a rammed or drilled channel in the ground, which is lined with a pipe. In this tube is the suction hose, which transports the collecting water to the surface through the suction power of a pump. A certain water level in the well pipe is required for the unit to be able to suck in water. This column of water inside the well pipe provides additional support for the pump due to its own weight and is already included in the way the suction pump works. Otherwise, an enormous suction power would be required, which is in no realistic relation to the actual promotion.
Water column falls: reasons and solution
If the water level drops, either the pump reaches its performance limit or the canal is completely emptied. In both cases there is no funding. Therefore, depending on the reason for the falling water level, you should take measures to keep it at the required level.
Old water pumps are no longer as efficient.
Delivery rate too high
If the performance of the pump you use does not match the groundwater flow in the borehole, the excessive performance can suck the well empty, and the water level drops significantly shortly after production begins.
You can do that
- Reduction of the flow rate (for pump types with adjustment option)
- Replacing the pump with an alternative with less power
- Reduction of the pumping intervals in order to maintain a minimum water column
Falling groundwater level
The groundwater level can change for a variety of reasons. It drops regularly, especially during the drier summer months. If the well is not deep enough, the flow of groundwater is reduced and, in extreme cases, it can even come to a complete standstill.
You can do that
- Suspension of production until the groundwater rises again
- Deepening of the existing well bore into the layer that now carries groundwater
Garden irrigation with sprinkler system
Attention: Not every groundwater lowering is of natural origin. With large flow rates, your well construction itself can also contribute to the sinking water level in the subsoil.
Sanding borehole
Depending on the nature of the soil, the flow of groundwater can wash sand and other soil components into the well or the layers of earth immediately surrounding it. The result is a reduced afterflow of groundwater as soon as the pump begins to deliver - the water column falls.
You can do that
- Flushing the well (only partially effective)
- Reduction of the pumping intervals or output to take account of the lower after-flow
- Creating a new hole
Leaking well pipe
If the lining of your well, within which the water column builds up, is leaking, the water can get back into the ground - the water level drops.
You can do that
- Seal well pipe or replace
Check well pipe
Tip: First check all connections or valves (especially the non-return valve), taps etc. before you check the actual well pipe for damage. In most cases, these components are much more susceptible and are often the cause of the fault.
frequently asked Questions
Can a well bore simply be deepened or renewed?Irrespective of the procedure, i.e. in the case of drilled, flushed or rammed wells alike, intervention in the soil and groundwater may only take place with the approval of the competent authority. Such approval is also mandatory for any change or renewal.
How to determine the reason for the sinking water sand?It's best to use the rule of elimination and do the simple steps first. Damage to the fountain technology is already visible during a visual inspection. On the other hand, changes in the groundwater can only be recognized by you as a layman if all technical problems have been ruled out.
How deep does a functioning well bore have to be?That cannot be answered in general. On average, the groundwater in Germany is 4 to 6 meters deep. A well depth of around 8 meters is therefore usually sufficient to create the necessary water level for production. In the case of strong summer sinking, however, significantly greater depths may also be necessary to maintain functionality.