Prior to construction, the site was serving as a practice soccer field. It had very little slope, and its location next to Clark Field and Clark Racquet Center (and near Eby) made it an excellent site for a permeable parking lot. Upon beginning excavation, we found that the soils were sandy and drained very well.
The lot was designed to detain a 1.25" rain in 24 hours ("water quality" design criteria). In other words, the void space in the rock chamber underneath the parking surface will hold that quantity of rain and allow it to infiltrate into the sandy soil beneath the rock chamber. If there is more rain, the overflow will go to the storm sewer. However, we anticipate that the sandy soil underneath the lot will allow it to handle an even larger rain event by quickly infiltrating.
The lot was designed to detain a 1.25" rain in 24 hours ("water quality" design criteria). In other words, the void space in the rock chamber underneath the parking surface will hold that quantity of rain and allow it to infiltrate into the sandy soil beneath the rock chamber. If there is more rain, the overflow will go to the storm sewer. However, we anticipate that the sandy soil underneath the lot will allow it to handle an even larger rain event by quickly infiltrating.