With the football field cut down into the ground, drainage issues would become more of a problem for the field. The field would need much to remove water from it much better with a better interior drainage system. Having a well preserved crown of the field is one of these keys. Using a slope of about 1.5/100, an ideal crown should be about 18” higher in the center than on the edges of a field. This keeps water from staying on the field, and allows it to drain to the sidelines where piping can be installed and carry the water away. These pipe drains, spaced at increments of 17.5 feet and 2-3 feet below the playing surface do a great job at funneling water to specified basins that hold excess water, and can even be a source of fresh water for the school. Most of my information was gained from this article: by Sports Turf- http://www.stma.org/sites/stma/files/EDigest/Drainage-3-Installed_FINAL_reduced.pdf