Can A Swimming Pool Be Too Full?

As a pool owner there will be times that your swimming pool becomes overfilled with water.  This can happen quickly after a spring storm drops several inches of water, a wetter than normal season or even by forgetting to turn off the water hose when replacing evaporated water.

This can cause the water to completely fill to the top of an above ground pool causing water to spill over the walls and underground pools to be much deeper at the entry steps.  This will have some people wondering if they should immediately drain to the water to prevent damage to their pools liner or walls.

If your swimming pool has become overfilled with water due to rain or forgetting to turn off the water hose, you do not need to worry.  While pools do have a recommended fill capacity, you do not need to drain your water if it exceeds that volume.  Over time the water will reside to the normal levels from evaporation and regular use.

There are a few reasons however, that you may decide it is best to go ahead and remove some water to bring the levels back to within the normal range.

Effects Of A Pool Overfilled With Water

The main issue that you will have if your swimming pool has too much water in it is the ability for the skimmer to keep the surface of your water clear from floating leaves, grass and bugs.  This will only occur if the water levels have risen so much that the entire skimmer beneath water.

While this will prohibit your filtering system from cleaning the objects floating on the water, it will still be cleaning the rest of the water normally.  In fact more water will be filtered through the skimmer during this time than if the water was only partially above the opening.

Above Ground Pools

One of the most common concerns some people have is that the walls may begin to have too much pressure and weight from the excess water.  There could be a few reasons when it may become a reasonable issue, but in most cases you should be fine.

Here are a few reasons you may wish to lower the water in your above ground swimming pool.

Pool water is over full covering a pool skimmer.
  • Pool is not completely level and the excess water has placed an increasing amount of strain on the sidewalls.  For more information about this check out my article explaining how much the water weighs and the effects on the sidewalls..
  • The water is flowing out of the top of the skimmer or over the sidewalls.  While this is not a particular bad thing, depending where your pool sits and the effects it is having on the ground around you can be.  It may be better to use a backwash hose and flush the water to another area so that your ground can dry up around the pool.
  • There is a lot of floating debris on the water and manually removing it would be less effective or a time consuming task.  This can be particularly true if you have cottonwood trees, high winds and other situations that make the surface of the water harder to maintain without a skimmer.

Underground Pools

It is less common for owners to worry about an underground pool that has been overfilled with water since there is no additional force on the walls and in some cases a swimming pool is designed to be filled beyond the top surface.

There really are only a couple issues that need to be looked at when it comes to below ground installs.

  • The depth levels that are posted for swimmers may be inaccurate.  If you have an area that is designed for kids or swimmers that are shorter in height and the depth level is deeper than what is indicated, it may be advisable to drain some of the water.
  • Just like the above ground pool setup, the skimmer may be completely covered which will not allow the surface of the water to be cleaned properly.  In many underground pools the skimmer is setup in a manner that will usually not have this problem, but this could be an issue in some cases.


When draining the water you are also removing the chemicals that have been added to the pool water.  If you are not in need of a routine backwash, it is best to not have these removed as it can reduce their ability to keep the water clean.

After a heavy rain, it is usually necessary to increase the amount of chlorine as the water becomes diluted.  Reducing the water would also reduce the amount of chemicals in the pools water and would not be as effective at keeping allgae and bacteria from developing in the water.


If you have had a recent heavy rain event and the level of your pools water has increased above normal levels including completely covering your skimmer, there really is no need to drain the water.

In fact, the thing you might should be doing is increasing the chlorine levels and checking your alkalinity and pH balance.  The additional rain water most likely caused your chlorine levels to become lower and may have also caused your alkalinity to change.

You can find more details on what  you should do after a rain storm has passed with my article that talks about what you should do to your pool after it has rained.

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