So I'm rather curious, now...
I'm just outside of Atlanta, Georgia. We recently broke a 132-year record for the number of days without measurable rain. We haven't had rain in about 50 days. We got about 2.3 inches inches of rain yesterday within about an 8 hour time period. We got well over a half of an inch today in about 2-3 hours with some extreme thunderstorms and downpours. Nearly 3 inches of rain in two days and I see absolutely no water flow in the floor of that hole, apart from the expected little bit that runs under the crawlspace door into the wall/hole, which I will address in the future. That was barely enough to put 2-3 inches of water in the existing pit in the floor and nowhere near close to triggering the pumps.
The difference between the last time we had a big rain event like this and this time was I filled in the 7.5'L x 4'W x 4.5'D old concrete septic tank that I finally found in the back yard a couple of months ago. Filled that with 7 cubic yards of fill dirt. That tank was not far from the back of the house.
Would the drought have caused the dirt to soak up all of that rain and not flow into the crawlspace, or did my filling of the septic tank stop water flow coming from that hole behind the crawlspace wall? I'm kind of suspecting that water flowed out of that hole, but also around and in/through the wall blocks all the way around the wall. It is only washed out in that area. The rest of the sides have dirt all the way up to the top of the wall and no evidence of any water washing it out. The debris also isn't flowing into the hole through the wall.
I have compiled this one large image with a description of each thing that I have observed. Am I thinking within reason here or should I still continue trying to fix this and assume that it might come back if it rained even more?
http://oi66.tinypic.com/34z0m4h.jpg
I expected to come home today and hear at least one pump coming on and go down to see water flowing across the floor. I see nothing. Do you think it just didn't rain enough or what? Usually that much rain seems to trigger the pumps and water would be coming out from every crack and hole all the way around the way around the wall that it could find. Mostly from behind that particular area with the hole in the dirt. Nada today. All of the rain is gone.