Well, I'm back with some interesting information. Haven't been to the courthouse yet (looking like yet again sometime next week) and it is in the 20's outside with a bit of ice/snow. Still not a good time for digging.
I looked around online and found some old topo maps from the early 1900's. One in particular that seemed helpful was 1927-1930. The maps are in a local college map database. A blogger on the site used some type of software and GPS features to overlay the topo map with the street names and such that weren't originally on the topo map. I opened a second window of the modern Google Maps and compared both maps side by side, then took a screenshot of both together for reference. I measured the same distance in the map views and had both maps looking identical in size in order to make an accurate measurement. Plus, the old map had one of those 1 inch = xxx feet deals that helped out.
Near our main intersecting street up the hill, a random branch of water "begins" somehow. You can see it at the bottom of the pic near the "H". Nothing was cut off from view. It literally begins/ends at that point and nothing else is visible on the other side of the main road. It flows down and appears to flow somewhere right underneath our property, perhaps both the front and back yard in a perpendicular curving fashion. Then it appears to continue on down the street, winding back and forth. The house at the end of the street on the corner...we stopped and confirmed that there is an open ditch of sorts. Probably 2 or 3 feet deep and a couple of feet wide, at least. The visible part is straight, but according to the map, it must curve around up under the road and go to the house that I mentioned before that had the little bridge over a ditch in their front yard. From that, the map shows it flowing into the creek that runs right along their yard, just to the right of the bridge. Note that their yard is, of course, elevated above the creek. So that makes it impossible for this to be a branch-off of the creek, particularly since our street has a considerable slope and water doesn't run uphill.
I put my best estimates on the map in red text and symbols based on my measurements with the current and old maps.
Oddly enough, it doesn't flow like I expected. If it does in fact run through our front and back yard, it goes perpendicular under or near our house, whereas I expected it to run side to side through all of the back yards. It obviously doesn't do that, so that must be some other totally different land issue with the neighborhood due to the slight slant of the hill going down the street. I can't stay for sure that it is directly under the house, but even if it is a little off, the way it curves around the area near our house would still suggest that it is at least likely running through our back yard. Per the map, it is definitely flowing perpendicular to the "stream pattern" of water that I see running through the middle of our yard during really heavy downpours.
Any ideas/opinions?
Had a nasty part of winter storm Jonas, a bit of snow and ice, and temps in the 20's. It started raining around the late afternoon on Thursday, rained through the night into Friday and then turned into sleet and snow Friday night/Saturday morning. So this time we had maybe a day or a little over a day of actual moderate rain. The smaller pump came on and has come on since. This morning, it was coming on about every 30 minutes. Now it is down to about every hour or so. I went down to the crawlspace and only see a very tiny trickle from the far side of the wall, so that's apparently all that is causing it. However, it usually doesn't make the pump come on until it rains for at least two days or more. So that's a bit odd. Yet with all of that discharging, no ice outside on the ground and no issues with the pipe freezing. Even in the 20's outside with heavy winds, the furnace vent pipe keeps it in the 50's in the crawlspace.
Another site that I found that shows flood maps and flood plains shows our property as a "moderate risk" for some reason.
As figured, they started all of this by digging and putting that water heater down there. If it were level and nothing but a crawlspace, I doubt we'd have any issues. Very odd that it comes on only when it rains, however, especially with that underneath.
Here's one more interesting thing in the neighborhood: two houses up on the opposite side of the street, that house has always had a driveway that floods badly when it rains. Between their driveway and the yard next to them, there is a little cement culvert of sorts. It is ground-level with grass growing in it, so it isn't a ditch. It is about two feet wide and has a cement or concrete wall on each side that is about a foot tall. I guess it could have been a culvert that might have filled with dirt over the years or something. Anyway, if it rains for two-three days moderately or even if we have had no rain and get a single terrible thunderstorm, I have seen that little culvert and their driveway combined put out enough muddy water to cover half of the street in half of a foot of water. I have no idea what that is, and their house wouldn't be anywhere near the water source I mentioned above on the map. While none of that water flows into our yard, it rushes down the opposite side of the street and into the sewer. Definitely thousands of gallons per minute. I thought that maybe that might give some type of indication of the neighborhood. Maybe some type of drain? Very odd that it leads to their backyard between the houses, though. Maybe a thousand feet or so down the street on the same side (opposite from us), they have a very similar culvert-like structure that is level with the street, with the same type of walls. It also comes between the two yards and leads to their back yard. I presume this also happens there when it rains. What the heck could these be? I don't know of any on our side of the street, but I guess there could be some. Some type of ancient drain systems?
A big question that I have right now is...we had maybe an inch of rain Friday and Friday night. Way less than we've had a lot of times when the pump came on. It hasn't rained since midnight on Friday. It has been a little over a day and the pump is still averaging a full pump out of 80-90 gallons per hour. I don't understand how that same water from 20+ feet away from the house could be coming back into the basement again when it hasn't rained in a day and the water is most definitely flowing towards the other yard. I even physically moved the flex pipe as an experiment to right next to the fence so that I know for a fact that it was going into the other yard, just to see (note that the neighbor never even goes into his backyard for anything and this is far from his house). Still averaged an hour in between each pump cycle. Granted, there is only a small trickle in the basement that is causing this, but I don't understand.
