Feature Stories

Students Design Rainwater Collection Systems

Students who learned engineering drafting techniques in a required course helped improve the community garden at UT's Kinsolving Residence Hall.

Tom Krueger, who teaches the first engineering graphics class (ME 210) that civil engineering students take, likes to create class assignments that are relevant to real world problems. Ealier this year, Krueger and his students worked with the UT Austin's Division of Housing and Food Service, to design two rainwater collection systems for food and herb gardens, at two campus dormitories, Kinsolving and Brackenridge. The gardens are also used for teaching sustainability.

This required course, offered only in the Mechanical Engineering Department, has similar courses offered for mechanical and aerospace engineering students, but the assignments vary depending on the student's major. Students learn engineering drafting techniques as well as 3D-modeling as they learn to use the engineering software modeling program, SolidWorks for mechanical and aerospace engineers, and AutoCAD and Autodesk Inventor for civil engineers.

Students were divided into small groups and tasked with working with the "clients" to determine their exact needs.  Both garden areas needed to have a self-sustaining water supply. The Kinsolving garden, for example, uses 300 gallons of water a week. The students determined the size, placement, and tank design based on Austin's average rainfall and the amount of runoff from the roofs. They then measured and made 3D models of the buildings and tanks in order to gain a clear understanding of the roof line design that would provide the runoff water.

In consultation with the personnel in the Housing and Food Services Division, the teams were required to do the following:

• Measure the existing and proposed garden beds to determine the amount of water they would require if they needed an inch of water per square foot per week.
• Determine the square footage of roof area from which to collect water. (Floor plans were obtained from the Physical Plant.)
• Determine the average yearly rainfall for the Austin area.
• Calculate the amount of water generated per square foot per inch of rain.
• Calculate the amount of water 1 inch of rain produces on the chosen roof area.
• Specify the size of a tank to hold a three-month supply of run-off for the roof area chosen.

The teams toured the facilities, took their own measurements, and architectural drawings were provided. The students made 3D models of the buildings to help visualize the properties and the roof construction. In addition, written report were reviewed by their clients.

The rainwater collection system that was implemented incorporated different aspects from the various teams. Two smaller tanks were used instead of one larger one in both locations, as some of the groups specified, since the smaller ones are easier to manage and take up less space.

In the end, the clients were pleased with the work the students submitted. Class evaluations from the students enthusiastically reviewed the opportunity to work on a "real engineering" assignment.

"As a future Environmental Engineer, I couldn't have imagined a project more suited to my interests," said Chandni Patel (civil enginering sophmore). I never knew the potential that rainwater storage systems had, and now feel the desire to put tanks on the side of every building I see. Here in Austin, water is especially valuable, and now that I know how effective a water tank can be, I will bring it to the attention of every company I consult for in the future. Who knows? Maybe I'll even put a rainwater storage tank on my own house!"