ᐅ Cistern and Potential Issues with Water Drainage

Hello everyone,

I have a somewhat unusual question, and as amusing as it might sound, I ask for a as sober an answer as possible—and yes, it is (unfortunately) serious. Here is the situation: Near the house—about 3-4 meters (10-13 feet) away—there is a "large" concrete cistern (big enough to stand in) and a submersible pump. It does not have a sewer connection because that was too expensive for the builder. When it fills completely, it simply overflows, and the water soaks into the surrounding soil.

So, what is the problem? The builder has an irrational fear that when the cistern overflows, the water will erode the foundation under the house and cause it to literally "collapse." In extreme cases, this leads to him sometimes running out into the garden in heavy rain to set up a sprinkler and pump water from the cistern into the garden (yes, we end up watering the garden even when it’s raining!) to prevent overflow. Or he gets up at night to turn on the pump and let water from the cistern flow into the garden, or he spends half a day on "rain preparations," meaning he moves the sprinkler every half hour to “water continuously and prepare the cistern for incoming water.”

As amusing as all this sounds, it is incredibly stressful to deal with—constantly setting alarms, checking the weather forecast, and running out into the garden with a flashlight or in the rain to prevent a problem that, in my opinion, doesn’t even exist. So, what is the truth? Could the whole house actually shift or collapse because the cistern next to it fills up? What can be said to help convince this person?

Best regards and thanks

Welcome to the forum, you are not alone with this problem. Anyone who has experienced flooding or rising water can understand.

In your case, a submersible pump with a float switch can help. When the water reaches the activation level, the pump automatically starts and lowers the water level in the cistern.

Where to direct the water? Into an underground drainage system, to a large hedge above ground, or into a rain barrel at the end of the garden.

Then you won’t have to rush outside in panic during rain but simply monitor how the automatic system operates.

This should help you sleep more peacefully at night.

Nida35a schrieb:

Welcome to the forum, you are not alone with this problem. Anyone who has experienced flooding or heavy water intrusion can understand.
In your case, a submersible pump with a float switch could help. When the water rises to the activation level, the pump automatically starts and empties the cistern.
Where to direct the water? To a buried drainage system or an above-ground large hedge, or into a rain barrel at the far end of the garden.
Then you don’t have to rush outside in panic during rain but just watch how the automatic system works.
That should help you sleep better at night.

Hello, thanks for your reply!

Actually, we already have a pump, a Tipp 30136 submersible pressure pump Drain 6000/36. It apparently even has a float switch. Currently, the system works so that the electrical circuit first needs to be switched on via a switch in the garage, then the socket is turned on remotely, which starts the pump. It’s not an ideal setup; the manual switch seems to be there to prevent the pump from starting “randomly” if someone accidentally switches on the socket remotely or if a wrong signal occurs.

The water is currently pumped manually to the hedge or diverted onto the lawn with a hose. However, I’ve also read that a cistern must overflow occasionally for self-cleaning—is that correct? I’m not exactly sure if there is a drainage system installed. The rain barrels are connected to a different roof and are filled separately.

There has never really been water in the basement, I believe only once or twice in 30 years from backflow through the sewage system (which is now prevented by a backwater valve, but its maintenance and issues are another story *sigh*).

So, theoretically, the options are:
- Consider the overflow as harmless, especially given that heavy rain is very, very rare here.
- Automate the whole system as much as possible with the float switch, accepting the minimal “risk” that the pump might be triggered by stray signals. In this case, the power in the garage could be turned on “when needed.”

Am I understanding this correctly?
Best regards and thanks

A submersible pump with a float switch should have a constant power supply, so it operates automatically. I am not aware of any interference or stray signals that would activate a submersible pump.

Nida35a schrieb:

A submersible pump with a float switch should have constant power supply so it operates automatically. I am not aware of any stray or interference signals that would activate a submersible pump.

I believe the interference signal is more likely affecting the remote-controlled outlet, causing it to switch on and then the pump runs continuously and overheats, or so is the concern. However, the specific model in question does have an overheating protection feature, as far as I can tell. I will bring up the issue of having it powered continuously.

Best regards

The pump only turns on at the upper switch point and turns off again at the lower one.
When water arrives, it rises to the upper level, is pumped out until it reaches the lower switch point, and the pump then switches off automatically.