I think the best advice for that kind of situation is really to do it the old fashioned way. Hand check the moisture. You can use a screw driver to see how deep the moisture is. Check it and keep it moist until it comes back.

My experience has been that the structure underneath the soil adds heat, so not only is it a shallow soil but warmer than surrounding areas. A possible solution might be a drip irrigation line or soaker hose. Seems treating it as new seedlings for a few days to get the moisture back in the soil and then taper back using rcnaylor's suggestion would be right.

I grow prairie grass and wildflower mixture over our septic field. But if you want a turf, then you might want to try a fescue blend rather than kbg in that area?

Thank you everyone!

Joe, I do want a turf over that area, mostly for my 3-year old son's enjoyment. The problem is that there is no depth for the roots to grow into given the shallow burial of the septic system. Fescues are relatively drought-tolerant because they send down deep roots. But roots just can't grow deeper than the concrete tanks, etc. in these areas, so their "drought tolerance" is theoretically true but just non-existent in my situation, where those plants could never establish deep roots. I planted bluegrass because it roots more shallowly and returns from dormancy more easily than the fescues. At this point, I am just hoping that I can bring the bluegrass out of dormancy without major die-off.

I hope that makes sense.

Thanks again,
Paul

Best way? Irrigate.

Paul, keep that area wattered whenever mother nature does not provide, but if you do let it go, you still need to water at least once every 2 to 3 weeks in order to keep the crowns alive.

I intentionally left this part of my yard without water for testing purposses, it went semi-dormant, but it made a full recovery in less than 3 weeks.

How shallow is the soil above the septic tank? How many inches?

Paul, this is the area I was refering to:

{{gwi:98054}}

It's fully green today with zero damage.

Thank you Auteck. Whoa, your photo makes me think I wasn't really clear on the "straw" look of my grass. I mean the affected areas (basically a perfect rectangle over the tank itself and then more spotty areas over all of the gravel they must have laid and the two drywells and the hi-lo or whatever it is called), look more like your concrete walk than your lawn, in color if not texture. I'll have to take some photos but it is too late tonight and I have a busy day tomorrow. But soon... In the meantime picture a very uniformly dark green lawn with absolutely tan and dead straw lying down over the septic system. Looks for all the world like fungus damage, but it just traces the underground structures too well for it to be anything but drought stress

Anyway, the soil in those areas is no more than five inches, and in some places closer to four. I had planned to build it up a few inches last year, but then realized this would cause the grass to grow up into the wooden siding of my garage. The only real solution is to bury the septic system deeper, but that is out of the question now in a practical sense, since it is already installed. My contractor made some bad choices, and I did not know enough to realize it at the time.

I have given the area a good soaking, certainly deep enough to reach the concrete. So I think that now I will just keep the ground moist as if I were starting new seedlings, but to a somewhat deeper depth and with a little more tolerance for drying out of the surface until it comes back. When more rain and less heat come in late August, hopefully it will be more able to take care of itself for the next ten months. But I think the big thing is that by starting to water in any way at all a day or two after the dormancy really showed, I hope I can still save most of the young (seeded last fall) plants without needing to reseed this fall.

...which would prevent my applying Dimension to keep the Poa down...

Sigh.

Paul

I have the same problem with my front yard and did the same thing Paul did last summer. I have a bare spot over my septic tank and the lawn over the septic system itself takes a beating over the summer. The sun justs heats up the stone under the soil there and the concrete tank, besides being heated by the sun also generates heat as part of the decomposition process enough that in the winter it melts the snow on top of it. My lawn (and house) is only 2 years old. I wish I had the foresight and the funds to install an irrigation system at the time. This Fall I plan to renovate that smaller area over my system again and really get it to take properly.
Jeff