Sump, no pump

I have run into sump pits with no pumps before, but they where always dry so I would advise monitoring the situation and if they see water in it, buy a pump. But today there was water in a sump with no pump (see picture, taken in a north Denver CO suburb.) My other problem with this picture (you may not be able to see it, but take my word) is that what I think are perimeter drains coming into this pit are coming UP at an angle. So at first I thought maybe the idea was that if the water level in the pit gets OVER the pipes, they drain it away. But why two? Now I’m just all confused. Anybody have any good reading material on these systems?

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I’ve seen some gravity sumps that when it reaches the point of the piping it just drains into the city systems…if that is allowed in your area. No pump required. Some only have water in them at certain times of the year and not enough water volume is present and they just let it evaporate away.

If the pipes are running up from the pit, they are likely draining into the pit from some other location eg. condensate drains, things that don’t contribute a lot of volume but need a drain…and this was the closest thing?