Oh, I have never heard of one. Are these more common with people in flood zones? Or what makes them neccessary for some homes?
There are many areas where the 'water table' - the level of water underground - is considered high, or there are drainage issues when it rains. If you have a basement, this can cause a problem because water naturally wants to flow somewhere. It's going to find the path of least resistance and since concrete is naturally porous, it is going to find its way through a concrete basement.
When our home was built, a french drain was installed around the perimeter of the basement. This is a deep trough that is purposely slanted and a perforated pvc pipe laid in the trench, covered with gravel. It is designed to provide a 'path of least resistance' for the water before it gets to the concrete walls/floor of the basement. The water moves through the gravel (to capture silt/dirt), goes into the pipe through the perforationsand travels downward in the trough (because the trough is slanted) and pours into a concrete 'pit' that is just inside the basement walls...it's called a sump crock. The water goes into the crock and inside the crock is my sump pump. Mine works off water pressure, so the pump sits there and once the water pressure reaches a certain level (indicating the crock is filling), the pump kicks on automatically and pumps the water upward and out of the basement to a drainpipe that runs to the street-edge of my property and deposits it into a field drain.
I actually have two crocks and pumps in my basement - opposite corners. both are connected to marine batteries so that if the power goes out in a storm, the sumps will operate for up to 10 hours. It's vital...the original pumps in my house were float-arm and as the water rose, an arm on the pump would rise up and when it reached full vertical the pump would kick on. Over time the pump had moved around in the crock until the arm was lodged against the edge of the crock, and when the water started to fill the arm simply couldn't raise. With no where to go, the crock filled up and the french drains around the basement filled as well...with no where to the water to go. It started to seep under the walls of the basement and percolate up through the slab.
We do not live in a flood zone. We could still get it if we wanted it - anyone can buy flood insurance if you're willing to pay for it. Fact of the matter is that you could live in a land-locked state, no where near a body of water, and still benefit from flood insurance because it covers any water incursion into your home from the ground, unless there is another proximate cause (for example...a tree smashes into your house, opening up a hole that allows rain to pour into your basement...you'd be covered, because it was the tree falling and opening up the hole that is the cause...not just the water coming into the house).