Water Drainage System
A sump pump is a water pump built and intended as a water drainage system for basements and concrete foundations. A sump pump pumps out water from a sump pit that is basically a well dug down under the floor level of the basement. The dug well is created by breaking through the concrete floor, using a jackhammer, and a shovel to get down several feet under. The placement of the sump pump will either be on the floor of the basement, adjacent to the pit/well, or in the pit itself. Above ground sump pumps are known as pedestal pumps, sumps in the sump pits are known as submersible pumps.
Sump pumps funnel water from the sump pits, and far enough from the perimeter of the house that it will not be able to reenter the soil around your home. The water that is drawn out of the pit is either channeled into the sewer line of the house, or at a location, still on your home property, but far enough away that it no longer poses a water problem to your basement/home. Laws vary by city/town on the legality of channeling the groundwater into sewer lines, so you should check with the appropriate authorities before embarking on a basement waterproofing project.
As stated above, sump pumps pump water out of the excavated sump pits, to a location where it will no longer cause your house a basement water problem.
How does the water get into the sump pit? Water gets into the sump pit by one of two means:
My gosh! All these fancy terms. What does it all mean? The bottom line is this. Water is very heavy, and it will move from areas with high concentrations, into areas of lower concentrations. If the soil around your home is highly saturated with water, it will try to squeeze your foundation, and come through and around the walls into your home any way it can.
- The groundwater naturally drains into the sump pit via gravity. That is why you or the contractor will want to try to build the sump system in the lowest level of the basement, so that the groundwater can naturally flow there.
- For your sump system, you may build a perimeter channel around the entire basement foundation, that channels the water into the sump pit. This more sophisticated basement waterproofing system is more expensive than the simple sump pit and sump pump, but it may be more effective if the sump pit alone does not draw enough water to lower the water table.
Sump pumps are often used in home locations known for frequent or periodic flooding. Due to a number of geographic or weather conditions, some places are more likely than others to have high water tables. The water table is the level of the soil, below the surface of the ground, where the soil goes from being relatively dry, to where it becomes highly saturated with water. Solid and sand with high water concentrations also have high hydrostatic pressures. Hydrostatic pressure is the pressure exerted by a liquid (or fluid mixture) at equilibrium due to the force of gravity.
Up next, how soil with a high water table can affect your home, and what to do about it.