by Dr. Yunus Salami, Associate Professor of Civil and Environmental Engineering
additional contributions from Justin Corwin, President of the Intersociety Council
November 26, 2024
LeTourneau University’s Air Dome project is a 120,000-square-foot facility that will create a premier indoor track and field facility, suitable for hosting major regional and national meets, as well as a variety of other spaces for athletics, academics, and recreation.
How does this project impact stormwater and the size of the campus’ pond?
As part of this project, the university’s three-quarter acre retention pond is being expanded to increase its volume so that it can hold more stormwater runoff. This is because the Air Dome project will replace natural land areas that previously allowed stormwater to infiltrate into the ground. In general, when an area urbanizes or adds paved and roofed areas, more stormwater runoff is generated and tends to stay above ground for longer. This stormwater must be managed to prevent flooding and pollution of waterways. Changing land-use by paving areas without providing best management practices for stormwater can quickly impact flooding and erosion, cause the stormwater to pick up and deposit pollutants in creeks or rivers, and harm aquatic life.
Can other existing stormwater management systems on campus help?
Some of the campus’ natural landscape like shrubs and lawns partly help manage stormwater because they slow it down, spread it out, and soak it in. Storm drains also help channel water from parking lots. But sudden large quantities of stormwater can overwhelm an area and therefore require larger or multiple systems for efficient stormwater management. Many cities also have permits that require as much of this stormwater to be managed on site for as long as possible and for ponds to be sized in proportion to the amount of impervious surfaces in the drainage area.
How much stormwater runoff is generated from rainfall?
Consider that if enough rainfall occurs over an hour to cause a half-inch depth of water to accumulate over a 10-acre area, and the area is split evenly between paving and natural ground, the resulting peak runoff would be a little over 1,100 gallons per minute.
Is the pond able to hold all the stormwater runoff it receives?
The existing retention pond was designed with a limit to its storage volume (currently just under one million gallons). So when the collected stormwater reaches a particular level, any excess gradually discharges through a spillway and further downstream into a creek. An increase in its volume will help hold even more stormwater on site.
What other benefits are there to increasing the pond’s size?
Retention ponds are environmentally sustainable due to their lower impact on the environment. The retention pond helps the campus mimic natural storage and drainage processes and improves water quality by letting pollutants settle in it. Stored stormwater is also used to irrigate the university’s outdoor sports fields thereby reducing water costs. Faculty often use the pond for research and teaching so a larger pond widens the potential options for these two purposes. Benches installed around the perimeter of the pond provide seating for students and faculty who want relax and enjoy the scenery.
How will this affect the annual rope pull?
Plans for adapting the rope pull are still being discussed, and will ultimately depend on the finalized expansion. It's possible the solution could be as simple as getting a longer rope, or pulling across a different part of the pond. In addition to the larger span, it's also possible that new features like a sidewalk or additional benches may have figure into the solution.
The design of features to manage the flow and drainage of natural and constructed areas is one of the jobs that environmental engineers do. If this form of stewarding our God-given natural resources appeals to you, learn more about LeTourneau's top-notch civil engineering and environmental engineering programs.