I have a stormwater drainage swale that runs from one side of my backyard to another. It works fine, but I would like to level up that area. Could I use a french drain in that area, cover it , and level up the area? If so, how do I size the diameter of the pipe to be used?

I have been living where I am for 16 years with a 2 acre lot and I always did my lawn preparation myself. This year, however, I decided to have a lawn care firm come in and do what they do in hope my lawn would be more grass and fewer weeds. After several months of their applications I was not happy at all since I have never seen so much crabgrass grow as it has this year. They had to come back several times to try to eliminate the crabgrass but all I have now is big brown spots where the weed died and now I see new sprouts of crabgrass growing. I have already discontinued their services and will be receiving a refund for the rest of the scheduled services. My question is: what can I do to start to get my lawn back in better shape even for next year. I don't have a problem with the retail weed and feeds but I'm not sure what is a good brand. I am planning to aerate and perhaps reseed. Thanks for any suggestions. Rich