Permeable Pavements, Grass Could Cool Cities, Clean Water

Engineers receive $2.6 million to complete three water sustainability projects in San Antonio.

UTSA professors will examine the use of permeable pavements such as interlocking blocks and permeable asphalt to help the city adopt better water infiltration systems and reduce the urban heat island effect.
UTSA professors will examine the use of permeable pavements such as interlocking blocks and permeable asphalt to help the city adopt better water infiltration systems and reduce the urban heat island effect.
UTSA

The University of Texas at San Antonio (UTSA) College of Engineering has been selected to receive approximately $2.6 million in city funding to complete three water sustainability projects in San Antonio.

Five UTSA engineering professors and one environmental scientist from the College of Sciences will work on behalf of the city to demonstrate the viability of permeable parking lots, to use roadside vegetation and trenchless technology to improve water quality, and to mitigate inner city flooding.

"At UTSA we continuously work to create innovative engineering solutions for problems that our communities find meaningful. These projects are another example of how we work to serve San Antonio," said JoAnn Browning, dean of the UTSA College of Engineering.

Two of the projects will be funded by the Proposition 1 Edwards Aquifer Protection Program.

The first project, spearheaded by civil engineering and environmental science faculty Vikram Kapoor, Samer Dessouky and Jeffrey Hutchinson, will evaluate the best vegetation to improve rain infiltration along major San Antonio roadways. The UTSA researchers will explore solutions to manage water runoff and filter toxic pollutants such as polycyclic aromatic hydrocarbons which can be found in soot or formed during the incomplete burning of coal, garbage, oil and gas.

"In arid and semi-arid regions such as central Texas, the use of native perennial and evergreen xeric vegetation in storm water retention basins represents a cost-effective method that may control sediment and pollutants," said Hutchinson.

The second project will be led by UTSA Civil Engineering professors Tom Papagiannakis and Marcio Giacomoni. It seeks to demonstrate the viability of permeable parking lots to reduce storm water runoff while lowering surface temperatures to mitigate heat island effects. This project will examine four alternative permeable parking designs made of (1) permeable asphalt, (2) plastic grid pavers, (3) permeable concrete, and (4) permeable interlocking concrete pavers. Water samples will be collected during storm events and sent to the UTSA Environmental Engineering laboratory to evaluate water quality. Pavement and water temperatures will also be measured on-site.

The Edwards Aquifer is the major water source for the residents of south-central Texas. The vegetation and permeable pavements projects will be funded for three years with the sole mission to improve water quality in recharge zones leveraging sustainable solutions.

The third project, funded by the FY 2019 Storm Water Operating Fund Adopted Budget, seeks to replace underground street pipes that channel storm water into creeks to alleviate flooding. The UTSA team, led by Civil Engineering Professors Hatim Sharif and Samer Dessouky, will test various trenchless technology with minimal disturbance to city streets.

"The city has miles of old corrugated metal pipes that are deteriorating in San Antonio. To replace that, it will cost billions and take more than 100 years," said Sharif. "The city is trying to find cost effective and fast solutions."

According to Sharif, within the last several years, corrugated metal pipes (CMP) have failed or collapsed in San Antonio due to severe corrosion. This has required the city to complete emergency pipe repairs and to mitigate pavement failures. The UTSA researcher estimates that about 26 miles of CMP have an "F" rating and require immediate attention.

The three projects are examples of how UTSA serves San Antonio to solve the grand challenges related to its fast-growing population.

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