A good water table is important in building a great swimming pool. But in the areas where the water table is high, construction of an in-ground pool is a tedious task. There are several things you should keep in mind while building a swimming pool on your property if your area has a high-water table.
Check the water table height:
First, determine how high the water table in your area is. Analyze this on a relatively normal weather and not soon after showers. This would give the correct picture of the average height of water table in your area. The water table is high mainly in coastal areas, the areas that fall below mean sea level and the areas that are depressed topographically.
Start excavating from the deep area:
Choose a deep end of the ground in your property and excavate from that area first. So when you dig the ground from the actual pool area, the excess water will have a place to flow into. The water that flows into the deep area can later be pumped out.
Manage ground level water flow:
This is especially important in areas where your pool would be built in a region that is lower than the ground level. In this case, you should dig out a small trench around your pool and cover it with stones. Layer this trench with a drainage pipe and keep the level of the trench lower than the ground level nearby. Runoff water, if any, flowing to your pool will flow to that trench.
Adjust the pool depth:
For an in-ground pool, a good builder would adjust the depth of the pool in accordance with the water table and not the height of the wall above the ground surface. Also, when you dig for the pool, dig a layer deeper than the actual pool depth. Below the pool should be your pool drainage system. This could also be left accessible so as to come in handy when a complete draining of the pool is required. Drainage pipes would run through the entire surface below the swimming pool and then would be connected to the drain pump on the surface outside the pool.
The tightness of the soil in the pool area would also affect the water flow. In areas with loose soil, you would need to fill in more gravels and stones to keep the water flow under control.
Removing the water:
When you pump out the water from the pool area, make it a point to pump it out to at least 50ft away from the pool area. This would ensure that there is no recycled back flowing water entering your pool. In the area where the water flow into the excavated area is more, dig further down than the pool height calculated. Make a slope towards the actual pool surface and cover up the excess depth with gravels and stones. On the deepest surface of the pool install a drain pipe, covered by a grate at the pool end, leading to the deeper end with the gravel.
