Beneath the fields there are tremendous water retention systems. Some systems are linear and are large corrugated pipes that carry stormwater to drains. These are approximately 6' in diameter. They branch out in parallel pattern to some holding tanks which store a large amount of water during over fill.
You will recall from earlier posts that the field was nearly to grade. Each of these areas get excavated several times in the process. This photo shows the dig and the gravel base that is being prepared to take the next set of pipes for the water systems at the stadium.
Then everything is filled back in and covered over raising it back up to the level of the fields. Finishing work on the actual surface will be much later, closer to 2010. The main stadium will have a turfed football and soccer field and track.
So beneath surface of much of this entire campus there are mazes of water systems, plumbing and electrical runs, and soon to come, wells for our geothermal water system.
SW reply: A question was asked if this was where we would store our water for reuse. No, these are runoff and surface water retention systems. Our cisterns for water saving will be in between the wings. Under the courtyards there will be six, 10 thousand gallon storage tanks catching roof water collection. This "Gray" water will be used for flushing toilets and irrigation purposes. One of the sustainable and environmental attributes in this new building design. :-)