We are on a very flat part of property and there is no great drainage... but... with the use of plenty of hay and some pine chips too, we have somehow managed to avoid mud in the runs. Of course I don't have anywhere near the number of chickens you do, but I know this particular setup of breeding pens will house a limited number of chooks. I have found that by regularly adding more hay and now and then adding a sprinkling of wood chips, I have built a living floor-type surface that seems to wick the water away. We have successfully kept the red clay from coming up through it. If you already have access to older hay, use it! It breaks down and creates a nice, rich soil as it decomposes. Healthy soil on top of the clay is what you want to shoot for, IMHO.
I would say the first matter of business would be to make sure the area you build in is not an area that naturally has a river running through it in a hard rain. Next time it pours, go out with some stakes or rocks - something to mark areas and make note of which areas become rivers or pools and which areas the water naturally drains out of.
I would also say that slope is not a bad thing. You want to build breeding pens... not a swimming pool, and inclines drain better than flat surfaces.
Just a few of my thoughts as I thought them... LOL!
I would say the first matter of business would be to make sure the area you build in is not an area that naturally has a river running through it in a hard rain. Next time it pours, go out with some stakes or rocks - something to mark areas and make note of which areas become rivers or pools and which areas the water naturally drains out of.
I would also say that slope is not a bad thing. You want to build breeding pens... not a swimming pool, and inclines drain better than flat surfaces.
Just a few of my thoughts as I thought them... LOL!