Find a map of what was on the land before it was developed. It may be an old stream bed or lake bottom.

I do not know what kind of tree was planted but with that slant at the top it is unlikely to grow without that bend always being there.

Could just be it is overwatering because it looks like clay underneath the sod and clay is very slow to absorb water. Have you talked to the neighbors and see if they have similar issues?

Here's some links that might be helpful. One is what to do and the other is from Texas A&M on how to water for example a lawn with different soils and how to deal with different soils and grasses in Texas. Clay needs slow watering as it is slow to absorb the water.

https://thrivingyard.com/water-sits-on-top-of-soil/

http://publications.tamu.edu/TURF_LANDSCAPE/PUB_turf_Lawn%20Water%20Management.pdf

Where is the french drain? And where does it exit?

Water is usually a pretty simple entity, it flows downhill and seeks level. That corner may be the low spot of grade elevation for you and the 3 other neighbors at this 4 corner convergence.

Lydia,
My neighbor next to us, where the issue is, have the same issue. The rest of their yard is fine. The sprinklers have been off for over 3 days and the back corner is still saturated. The little water puddles are dissipating, but I would think that would be gone after a day of 70 degree sunny weather. Thanks for those links, I will look into it.

3onthetree,
French drain starts near the center of the back fence and exits out to the front curb, through a pop up emitter. The contractor who installed the drains did not do a good job. This is the middle section of the drain next to our AC condenser unit. I’m not a drainage expert, but this does not look right.

I agree with you with the corner being the low
spot. I went by yesterday, nothing was done and we are supposed to close again tomorrow.

Can't really tell from pics what grade elevations exist. The corrugated might have a vertical bend peeking through the grass. Unfortunately, it will still drain at the point the water rises above the bend. I say "unfortunate" because it will still perform somewhat and a contractor can then excuse a poor install. If it is meant to be a french drain here they do not have a sock on it or wrapped gravel trench. If it is solid pipe to only cart away downspouts or from a collection point in the middle of the back fence, then it's just a sloppy (but typical) install with vertical bends.

However, if the pipe at the back fence is lower than somewhere along the side fence or pop-up emitter in front, it may actually be dumping water at the back, which is exacerbating the low point collection in the corner. You would have to evaluate the grade elevations in front compared to the low spot in the corner to see if you can drain it with piping.

As far as your closing, I'm not sure if this is a deal breaker. I don't know what the builder can be held to as far as providing a yard with no standing water. If this is the only problem with the house, I'd say carry on with the deal and fix it later yourself. Most builders/contractors are incompetent in site planning and underground drainage, so the current team probably cannot fix it.

BTW city inspection will not be looking if this exterior drainage is performing or not, receiving a Certificate of Occupancy means nothing on non- life safety issues.

Thanks for the advice, 3onthetree. So this was what was done today. Landscapers came in and replaced and rolled all the damaged/dead sod. They also covered up the exposed corrugated pipes. Did they fix the main issue, no, but I am glad they did something. After they ran the sprinklers, the same area got soaked with water again and the three valve boxes filled up.

The obvious thing to do is to adjust your sprinklers. You should be able to turn some sections off. If you can't, capping some or all heads in the damp zone should help.

Sprinkler systems also leak frequently. Check that.

I clay is part of your problem, try aerating your soil.

I live where the ground is clay. To me it looks like you've got a leak somewhere. There should not be that much water in the ground just because you're on clay. After all, that water isn't all over the place. They need to dig up the sprinkler lines. And/or re-grade.

I agree with Mrs. S. We experienced a leak that was behind a valve, so it was not obvious. As long as that zone wasn't running the meter did not spin. The leak was slightly below ground on a slope, covered with pine straw, so the excess water was not visible until the base of the slope near another sprinkler head. There was a lot of finger pointing by everyone who worked on the property, all of whom also said that problem was clay soil. We had to hire our own irrigation tech to find the location of the leak and make repairs.

At another house we also have clay soil and corrugated drain pipe similar to yours that run from the downspouts out to the street in front and far back yard in back. The excess water that was dumped in the far back yard pooled and that problem was never addressed by the builder. We hired some college students to dig up part of the back yard and create a dry creek lined with weed block and river rock, and edged with plants.

The city inspectors at the second house didn't care about grading or drainage. They only cared that no water was diverted onto someone else's property.

I think you guys sound spot on with the leak, in addition to the clay.

JP Haus, your problem sounds exactly like mine. Builder won’t do anything about it. I ended up closing today, but I made him document on the closing paperwork that he will schedule an irrigation tech to come out to reassess my sprinkler system.

Just a suggestion but make certain no water is being used inside the house and if possible watch the meter. Some utilities this is no longer possible or extremely hard to do. You may have to make a note of the reading and then check in an hour or so.

Meter does not move when the water inside the house is off. If it is a sprinkler, valve, or lateral line leak, I’m guessing it only happens when the system is on.

I had the same problem with my irrigation system last year. You need to dig around until you find the leak.