Lewis H. McMahan LEWIS H. McMAHAN of Dallas, Texas (chair, utility services committee). McMahan is the owner and operator of MWR Ranch, LLC. He currently serves as a member of the advisory board of Southern Methodist University’s Lyle School of Engineering, member on the Dallas Symphony Orchestra Building Committee and former member of SMU Alumni Board. He previously served as chairman on the Texas Instruments Foundation Board and as president of Texas Instruments Alumni Association, Texas Water Development Board, Dallas Regional Chamber Water Committee and past board member of the United Way of Metropolitan Dallas and the Dallas Museum of Art. McMahan earned a Bachelor of Science degree in civil engineering from SMU. McMahan was appointed as director for Dallas County in 2019.