Originally Posted by PaintHorseMares
We don't have a dry lot, but we have kept four mares in our riding ring for days. It's 100x200 (20,000 sq ft), so 500 sq ft/horse, and that's more than enough room without them being crowded for a corral/pen.
That's 5,000 sq ft per horse. 500 sq ft is only 10x50. I have runs on my barn that are 15x40 (600sq ft). They work but if they don't get out for days because of weather or my work schedule, they are climbing the walls. You only have about 14,500 sq ft to work with or an area about 100x150ft. What do you have to keep in that area? Only the horses? Dealing with mud is an ongoing problem when you have to confine them to a small area. One of the keys is to limit how much they can move around when there is mud. Walking stirs things up making it worse. I would look at making small feeding pens/holding areas at the high point of the pen. You can do as small as 12x12 (the size of a stall). Put down something like roadbase and slope it so the water runs out of the 1/3 acre (not into it). Covering the 12x12 area plus no water running into the pen and you won't have a mud problem there. The fencing has to be solid and able to withstand abuse. Panels, pipe or boards no wire or hot tape for the small area. You can use wire for the larger area to save money. Give it a day before you let the horses out of jail for the turnout area to firm up after it stops raining and even in heavy clay, there will be a dramatic decrease in the mud.