General Manager/CEO Darrell Nichols oversees policy development and implementation as well as daily operational and administrative activities for the Guadalupe-Blanco River Authority and its 32 operating divisions. Since joining GBRA in 2016, he has directed more than $800 million in capital improvement projects while managing project development, financing, construction activities, and water supply planning. The GBRA Board appointed Nichols as the agency’s seventh General Manager/CEO in February 2023.
Nichols has more than 30 years of experience in public utility policy, planning and implementation. Prior to joining GBRA, Nichols served as Assistant Executive Administrator and Director of Regional Water Planning and Development for the Texas Water Development Board. His previous experience also includes engineering and consulting experience in the private sector with a firm he founded as well as employment with the predecessor agency to the Texas Commission on Environmental Quality (TCEQ).
Education
B.S. in Civil Engineering – University of Texas at Austin
Deputy General Manager Jonathan Stinson directs the development and implementation of strategic programs and ensures compliance with GBRA’s governance, management, and statutory requirements. He represents GBRA as a voting member of the South Central Texas Regional Water Planning Group (Region L) and the Guadalupe Regional Flood Planning Group (Region 11).
Stinson serves on the Board of Directors and Executive Committee of the Texas Water Association and the Board of Trustees of the Texas Water Pool Risk Management Fund. He is also a member of the U.S. Water Alliance One Water Council, the National Association of Clean Water Agencies, the American Water Works Association – Texas Section, and the Water Environment Association of Texas.
Stinson has more than 20 years of experience in agency administration, public policy, and legislative management, including work on groundwater and surface water policy, economic development, and infrastructure financing. Before joining GBRA, he served as Assistant Executive Administrator for the Texas Water Development Board, a policy advisor to Governor Rick Perry on water, parks and wildlife, and agriculture, and as Legislative Director and policy staff in the Texas Senate.
Education
B.S. in Political Science – Texas A&M University
General Counsel Joe Cole provides legal counsel, opinions, and services related to GBRA’s responsibilities and operations and serves as an advisor to the Board of Directors and executive management. Cole manages litigation and outside counsel and oversees the development and review of policies, contracts, and other legal agreements.
Cole has more than 30 years of experience in environmental and water law, litigation, and regulatory matters. He has held leadership roles with the Department of Defense (DoD), the Environmental Protection Agency (EPA), and the San Antonio Water System (SAWS).
Cole served 20 years in the military and more than 13 years in federal civilian service, most recently as Associate General Counsel at EPA Headquarters and as Chief of the Environmental Law Field Support Center at Joint Base San Antonio Lackland.
Education
LL.M. in Environmental Law – The George Washington University School of Law
J.D. – Saint Louis University School of Law
B.S. in Education – University of Missouri
Executive Manager of Administration Vanessa Guerrero oversees human resources, education, facilities, safety, and information technology for GBRA. She leads the development and execution of long-range organizational strategies, aligning people, operational, safety, and educational priorities to support organizational effectiveness.
Guerrero led GBRA’s communications function from 2018 to 2024 and oversaw information technology infrastructure from 2018 to 2026, strengthening organizational performance and connectivity.
Guerrero has more than 20 years of experience in human resources and organizational development. She joined GBRA as Human Resources Director in October 2017 and was promoted to Executive Manager of Administration in 2018. She is a member of the National Association of Clean Water Agencies and the Society for Human Resource Management and represents GBRA on the State Agency Council.
Education
M.S. in Organizational Development and Leadership – The University of the Incarnate Word
B.A. in Human Resources Development – The University of the Incarnate Word
Executive Manager of Operations David Harris serves as Chief Operations Officer for the Guadalupe-Blanco River Authority, overseeing 10 water systems, 14 wastewater operations, eight pipelines, four hydroelectric plants, three parks, and one diversion system.
Harris is responsible for providing technical support for GBRA’s water and wastewater facilities and assists in the negotiation and development of major contracts. He also serves as a point of contact for water and wastewater utilities throughout the Guadalupe River Basin. Harris is a member of the Texas Water Utilities Association (TWUA) and TWUA’s Double A Club.
Harris has more than 35 years of experience in the water and wastewater industry and holds Class A operator licenses in water and wastewater treatment. He is also licensed in customer service inspection.
Education
B.S. in Wildlife Fisheries Sciences – Texas A&M University
B.S. in Rangeland Ecology and Management – Texas A&M University
Executive Manager of Engineering Charlie Hickman, P.E. leads the planning, design, and construction of GBRA’s capital improvement program, including dams, reservoirs, groundwater wells, pipelines, treatment facilities, and conveyance systems.
Hickman provides strategic guidance on hydrology, hydraulics, water quality, and infrastructure risk management and establishes engineering policies, standards, and best practices to support efficient project delivery. He also oversees property acquisition and coordination with federal, state, and local agencies to obtain regulatory approvals and secure funding opportunities.
Hickman is a licensed Professional Engineer with more than 20 years of experience in engineering and project management related to water resources, public works, and private development projects.
Education
M.S. in Engineering Management – University of Texas at Austin
B.S. in Civil Engineering – University of Texas at San Antonio
Executive Manager of Environmental Science Nathan Pence leads GBRA’s environmental department and science programs, including water quality, watershed protection, applied research, species management, and the environmental laboratory. He oversees development of a Habitat Conservation Plan for the Guadalupe River Basin and administration of the Clean Rivers Program in partnership with the Texas Commission on Environmental Quality.
Pence serves as a founding board member and treasurer of the National Habitat Conservation Plan Coalition and as chair of the Guadalupe Basin Coalition. He has more than 25 years of experience in watershed management and planning. Prior to joining GBRA, he served as Executive Director of Threatened and Endangered Species for the Edwards Aquifer Authority and worked for the City of New Braunfels on economic development and natural resource initiatives.
Education
M.S. in Aquatic Biology – Texas State University
B.S. in Aquatic Biology – Texas State University
Executive Manager of Finance/CFO Randy Staats is responsible for the overall management of GBRA’s finance department, leading all accounting and financial functions, including budgeting and financial planning, payroll, accounts payable and receivable, treasury and investments, risk management, purchasing, grant and construction accounting, capital assets, debt planning and administration, financial reserves, and administration of the defined benefit pension plan.
He also oversees financial reporting and preparation of the annual comprehensive financial report and serves as an advisor to the Board of Directors and executive management on financial matters.
A Certified Public Accountant and Certified Internal Auditor, Staats has more than 33 years of experience in finance, accounting, and auditing. He is a member of the Texas Society of CPAs, the Government Finance Officers Association, and the Government Treasurers’ Organization of Texas.
Education
M.Acy. in Accounting – Southwest Texas State University
B.B.A. in Finance – Texas A&I University