Fiberglass and High Ground Water

Usually, high ground water is not a problem except during install. Installers will “Well Point” using long PVC pipes they insert into the ground around the pool hole before it is dug, and using a pump, pull out ground water until dry enough to dig. 

After your fiberglass pool is filled with water and backfilled properly, the well pointing is removed and now the fiberglass pool shell is no longer buoyant. 

If you have normal high ground water table due to location near a lake, canal, or pond, you should ask your installer about adding hydrostatic relief valves to your main drain and to also add a Drain Field under your pool.

A Drain Field is a 8″ standing pipe that stands in a rock filled hole dug 12″ deeper than the deep end of your pool, and then additional 4″ perforated drain pipes wrapped in geotextile fabric and covered with gravel placed outside the edges of your pool in a rectangle and connected together.

After your deck is installed, the excess 8″ pipe is cut off level with the deck and a skimmer lid can be added to cover it.  

You would then add a sump pump which will have all the ground water under the entire pool (due to the horizontal drain pipes installed around all 4 edges of the pool and connected back to the standing pipe) drain the ground water to make it safer to drain the pool (which we never recommend unless by a professional). 

Those who don’t hook a horizontal drain field to the 8″ standing pipe only intend for the 8″ standing pipe to be a view port to see what the current ground water level is. You should never sump pump a single pipe not connected to any horizontal pipes, that only removes the ground water from a 3-4′ section of the pool and does not help the shallow end which is where most pool pops occur.