Picture 4. This is in the front yard. In the mornings these blades of grass have a pinkish hue. This post was edited by AdamHad on Sat, Jul 27, 13 at 16:27

Get some Tenacity and spray that (follow directions carefully) at seed down and 30 days later. At 60 days later you can use a normal pre-emergent. If you can't find Tenacity locally, it can be ordered through Amazon and other places. That will help prevent next year's crop of poa annua (and other winter weeds).

In terms of excess moisture, I just poked around a bit this morning on my way to work and noticed that the soil in that area was very wet. I also noticed lots of little bugs flying around that area! Also should add that a couple mushrooms have popped up in other parts of the lawn. With that in mind, I'm thinking a fungus has attacked the KBG and is leaving the fescue plants alone (so far). If you are not watering like the following paragraph describes, you should go there gradually over the next month. Watering: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall.

I live near Marysville WA, about 40 miles north of Seattle. Grass is a mix of rye and fescue. We have in ground irrigation which runs each of 17 zones for about 15 minutes between 2 am and 6 am every day except Saturday because I mow on Saturday. I only fertilized once this year with 16-16-16 fertilizer. I decided to put an application of the 16-16-16 fertilizer + lime + grass seed on this area and I did additional watering of about 2 hours twice a day and now these spots have pretty much disappeared. Yes, the builder mounded up the soil around the trees, or maybe he graded it down in the rest of the lawn. When we had the grass installed we had the contractor add some mulch/bark but we plan to remove this until we get down to the roots as you describe.