Is Sump Pump Supposed To Have Water In It?

The sump pump is installed with the primary purpose to collect and drain out water to prevent basement flooding. But you might ask yourself if your sump pump pit should be dry or supposed to have water in it. We did the research to deliver the right answers for you.

The sump pump pit is supposed to hold water but should normally be a little amount. If you get to see that your sump pump pit has no water, that is acceptable. The only time you should be much concerned is when the water level gets too high or your sump pit is overfilled most of the time.

But with a little water in it, the sump pump is perfectly great. Getting it overfilled indicates underlying problems. On the contrary, having no water at all in your pit is both a good and bad sign. Keep reading as we dig deeper into how the sump pump works and the acceptable water level it should maintain.

Plumbers materials and a sump pump used on the floor drain, Is Sump Pump Supposed To Have Water In It?

How Does The Sump Pump Work?

For every home, the sump pump is expected to hold a lot of water over its serviceable life. The water can be from any source and distance from your home. It can be a direct flow from rain or snow thawing out, water funneled from basement perimeter drains, drain from a dehumidifier, or a result of seepage.

Yes, water in your sump pump can come from your dehumidifier. Check out this post for a detailed read: Can I Drain Basement Dehumidifier to Sump Pump (And How To).

A sump pump inside a barrel with water

Wherever the source, the sump pump should be installed below the basement floor level or at the lowest point of your basement. It operates using a float switch or a “floater.” Just as the name suggests, it is a mechanism that stays afloat on the water surface. This floater activates the sump pump when water reaches a certain level, that is before the water reaches the basement floor.

When activated, the sump pump drains the water collected in the pit into a discharge pipe directed towards the exterior of your home. When the water level inside the sump pit gets low, like an inch or two from the floor, the floater can no longer float, hence the pumping stops.

So in this setup, it is very common to have at least a little water to stay at the bottom of the pit with the sump pump off as seen in the following photo.

A sump pump using a drawing water in the basement floor drain

We have listed below the different water level issues, with their corresponding favorable and unfavorable indicators, related to operating the sump pump. 

No Water in Sump Pit


  • Water is accumulating far from your house.
  • Lessened wear and tear of the sump pump.
  • Your basement has no water leakage, hence, no worries about flooding issues.
  • It is recommended to have the pump’s rubber and plastic components get tested to ensure that they should still be working when the need arises.


  • There is a possibility that water gathers in other parts of the basement.
  • The basement floor is not angled adequately to let water get directed to the pit.
  • There could be a mechanical fault in the sump pump that keeps it running even when the pit is dry.
  • It can be an indicator that your sump pump is not properly installed or the pump is not connected to the drainage system of your house.
  • You might consider digging another sump pit as water is suspected to be entering other areas of the basement. This translates to added cost. 

Little Water in Sump Pit


  • The sump pump is in good working condition.
  • The sump pump is activated continuously.


  • There might be a seepage problem within or around your house that needs to be closely monitored.

Much Water in Sump Pit

When the water level in your sump pump pit is unusually high, it can be a probable cause for alarm. Most especially when it has not been raining or you are quite aware that you haven’t activated your sump pump for some time.


  • It indicates that water flows continuously.


  • The float switch is jammed or worn out and might need a replacement.
  • There is a faulty check valve that lets water flow back to the sump pit.
  • There is a problem with the home’s drainage system that keeps the sump pump running nonstop.
  • There is a sump pump malfunctioning; it does not activate until the water level is unexpectedly high.
  • There is a clog or blockage in the discharge pipes that inhibit the draining of water collected in the pit.
  • The sump pit is too small or crowded that it fills up with water at a faster rate. This lets the pump turn on and off frequently, thus increasing wear and tear.
  • There are busted pipes, broken sprinkler systems, or broken sewer pipes somewhere near your property.
  • There could be a high water table. The remedy could be relocating the sump pump to a higher elevation, upgrading the system, or installing another pump.

How Do You Know If Your Sump Pump Is Working?

Having a sump pump installed in your basement, there are typically three scenarios or levels of “need” in terms of maintenance and operation.

  • Level 1 is when your sump pump is running constantly even during little or no rainfall.
  • Level 2 is considered the “ideal.”

Your sump pump doesn't activate normally but does when the need arises. This occurs during heavy rainfall and then automatically shuts off.

  • Level 3 is when your sump pump never activates. 

Now, your sump pump system should be regularly tested, at least on a yearly basis. Here's an easy and straightforward procedure where all you will do is just pour in water:

  1. Fill a 5-gallon bucket with water.
  2. Slowly pour the water into the sump pit until the float switch triggers your sump pump to activate. Your speed of pouring in water could be similar to the pouring in of rainwater.
  3. When the pump activates, ideally you should be seeing the water level slowly going down until it reaches the shut-off level.
  4. Otherwise, when step 3 does not happen, your sump pump system needs troubleshooting for any repairs or replacement of parts and wirings.

It is highly recommended to get a sump pump that best fits your specific needs. New models of sump pumps are powerful, that is, drains water faster and uses less electricity. There are added features such as an alarm system and a sophisticated backup power system.

Check out this Zoeller submersibble sump pump on Amazon.

How Much Water Gets Into the Sump Pit?

A plumber using a sump pump in the basement floor drain

There is no hard-fast rule on the size of the sump pump pit installed in homes. Industry practice is normally at 18 to 24 inches in width and 30 inches in depth. This dimension is enough to collect 30 to 35 gallons of water at one time.

When at full capacity, the highest water level of your sump pit should be just below your basement floor. The water should never reach beyond the mouth of the pit, or else, flooding will occur.

If your home is situated at a higher elevation, it might not collect much water and a small sump pit is justified. Or if you have installed the latest model of sump pump which is powerful and efficient and can drain water faster than the traditional types, a smaller sump pit could be sufficient.

The Takeaway

Plumbers materials and a sump pump used on the floor drain

One of the most obvious indicators to know whether your sump pump is functioning properly or not is how much water stays in the sump pit. A dry sump pit would be fine, as there are both favorable and unfavorable indicators.

The ideal setup is that your sump pit should have an inch or two of water level maintained when the pump is off. A high water level or an overfilled sump pit could be alarming and can be a prelude to a long list of deeper problems.

Additionally, an easy way to test your sump pump is by pouring water and observing the draining of water. The ideal sump pit size should be enough to hold water that will not flood your basement. Recent models of sump pumps available in the market today are more powerful and energy-efficient, thus a smaller sump pit may be sufficient.

For more insight about basement perimeter drains, you may check this post: How Long Does Basement Waterproofing Last?

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