There is a trench in my crawl space that was caused by years of drainage problems. It is about three inches deep around the foundation. I have installed a sump pump, but was wondering if I need to make the ditch larger and put in plastic pipe with gravel, or will one inch gravel alone be enough to casue better drainage directly to the sump pit. There is pea gravel covering the entire crawl floor with plastic over it.
Why don’t you start by correcting the drainage outside this crawlspace first? Don’t allow water to seep into the crawlspace in the first place.
If you convey the exterior water away from this crawlspace area, instead of allowing to seep into this area, it may just dry up on it’s own. But you won’t know until you set up exterior drainage first.
Then take further actions if this exterior drainage doesn’t take 100%.