Board Members

Timothy L. Hildenbrand, President 830-709-3879 Gina Mangold 830-709-3879 
Caroline A. Nentwich, Vice President 830-709-3879 Hector De La Fuente 830-709-3879
Richard A. Sultenfuss, 2nd Vice President 830-709-3879 Roy Tschirhart, Jr. 830-709-3879
JoNell M. Tarvin, Secretary/Treasurer 830-709-3879


Present Term August 2019-August 2022

Mr. Hildenbrand was appointed to fill an unexpired term on the Board of Directors in April 1999.  He was re-elected to the board in August 1999, August 2002,  2005,  2007, 2010, 2013, 2016  and again in 2019.   He held the office of  2nd Vice-President from 1999 to 2000.  In August 2000 he was elected Vice President.  In May 2006 he was elected President in August 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 and 2019. Tim has attended multiple conferences on water and brings to the board a vast and wide range of expertise in water related issues. 

Mr. Hildenbrand is a Certified Petroleum Geologist and has been involved in various aspects of the Oil and Gas industry since graduation in May of 1980.   Mr. Hildenbrand is currently employed by and an officer of, the Zachry Group of Companies.  He has a B.S. in Geological Engineering and his education also includes an Intensive Spanish Course, Proyecto Linguistiso Francisco Maroquin Antigua, Guatemala, Central America.

Tim, his wife and their children live in the rural area of Medina County.  Tim is active in community affairs and is also a rancher.

Mr. Hildenbrand currently serves on the Management Advisory Committee.

Present Term August 2018-August 2021

Ms. Nentwich was appointed to the Board of Directors in October of 2004 to fill a vacancy in the 2003-2006 term. Ms. Nentwich was elected as 1st Vice President in 2007 and continues to serve in that position on the Board. Caroline brings to the board 40 plus years of business administrative knowledge and skills.  She has attended numerous conferences on water related issues and Public Funds Investments.  

Ms. Nentwich has been in the business sector for over 40 years primarily in the Information Systems arena within the Financial Industry.  Ms. Nentwich has a Bachelor's degree in accounting with a concentration in Business Data Systems and a MBA with a concentration in Information Systems.

Caroline resides outside of Castroville. She has two sons Karl and Brian. Caroline is also a  rancher.

Ms. Nentwich serves as Chairman of the Wages and Benefits Committee and is on the Finance Committee.

RICHARD A. SULTENFUSS, 2nd Vice President
Present Term August 2019-August 2022                                                               

Mr. Sultenfuss was appointed to the Board of Directors in March 1993. He was elected to the board in August 1995, August 1998, August 2001, August 2004, August 2007, 2010, 2013, 2016  and August 2019. Mr. Sultenfuss was appointed as 2nd Vice President at the May 15, 2018 Board Meeting and remains in that position today. Richard brings to the board valuable knowledge of general operations of wells, pumps, and motors and is boiler certified.

Mr. Sultenfuss has an Associates Degree in Applied Science-Refrigeration, a Master Air Conditioning and Heating License, Water Analysis Training, a Factory Chiller and Pumps certification, and was a licensed H/VAC Contractor. He has recently retired from the Assistant Manager of Mueller and Wilson Inc. in San Antonio.

Richard and his wife Cindy reside and raised their children in the rural area of the southeast section of Medina County. He is active in community affairs and is also a rancher.

Mr. Sultenfuss serves as the Chairman of the Operations Committee.

JONELL M. TARVIN, Secretary/Treasurer
Present Term August 2017- August 2020

Ms. Tarvin was elected to the Board of Directors in August 1999.   She was reelected in August 2002, August 2005, 2008, 2011, 2014 and again in August 2017. She has held the office of 2nd Vice-President and is currently the Secretary/Treasurer.  She has completed a course in Public Funds Investment in compliance with the Public Funds Investment Act.  She has attended a number of conferences and seminars on water issues.   She brings to the board a reliable expertise in management and finance.   

Ms. Tarvin is retired from Southwestern Bell Telephone Co., where she worked for 29 years as an Area Manager.  She is also a certified substitute teacher.  

JoNell and her late husband John raised their family in the Dunlay/Castroville area.  Ms. Tarvin is active in community affairs and is a rancher. 

Ms. Tarvin serves as Chair of the Finance Committee and also serves on the Management Advisory Committee.

Present Term August 2017-August 2020

Mr. De La Fuente was appointed to the Board in May 2010 to fill an unexpired 2008-2011 term. He was elected to the Board in 2011. Mr. De La Fuente has been an East Medina customer for over 20 + years and has lived his entire life in the District. 

Mr. De La Fuente's specialty is evaluating oil used in agriculture and construction off-road equipment drivelines. He works with original manufactures providing technical support and developing new technologies. He currently works for Chevon Oronite Company and had previously worked for Southwest Research for 20+ years.

Hector is married, has 3 children and lives on the Pearson area. Mr. De La fuente is an active member with his church and community.

Mr. De La Fuente currently serves on the Wage and Benefits Committee.

Present Term  August 2018- August 2021

Mr. Tschirhart was  appointed to the Board in November 2010 to serve an unexpired 2009-2012 term. He was elected to the Board in August 2012.  Mr. Tschirhart's father was one of the original members of East Medina County Water Supply Corporation.

Mr. Tschirhart is currently retired with many years of experience in the plumbing supply field.

Roy and his wife Linda live in the Devine area.

Mr. Tschirhart currently serves on the Operations Committee.

Present Term Expires August 2020

Ms. Mangold was appointed to the Board in August 2018 to serve the remainder of an unexpired term. Ms. Mangold grew up in the rural Natalia area and has lived her entire life in the District.

Ms. Mangold is the Executive Vice President & Chiel Operating Officer for NEXT Oncology. She graduated from Natalia High School in 1986, Texas A&M University in 1990 with a B.S. degree in Biomedical Science and earned an MBA in Business/Finance in 1996 from Our Lady of the Lake University. She has over 25 years of experience in the field of oncology drug-development for treatment in patients with cancer. Ms. Mangold formerly served 11 years as a co-founder of South Texas Accelerated Research Therapeutic, LLC (START) and as the company's Chief Operating officer. In addition to those responsibilites, she also was CEO for START Shanghai. She previously served as Director of Research Administration and Manager of Preclinical Operations for the Cancer Therapy and Research Center (CTRC) in San Antonio.

Gina lives in the Castroville area with her husband, Brett Erpedling. She has two grown children, Amanda and Bradley, and enjoys fishing at the coast with her husband and traveling whenever possible.


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