HB 157 amends Section 341.0315 of the Texas Health and Safety Code to require the Texas Commission on Environmental Quality (TCEQ) to produce an annual report on public drinking water supply systems. This report, due to the legislature by September 1 each year, must include: (1) an analysis of significant events affecting water systems and their consequences, (2) a summary of challenges, vulnerabilities, and failures experienced, (3) projections on the physical condition of water systems and effects of population growth, and (4) recommendations to prevent unplanned downtime during disasters. TCEQ may collaborate with other agencies, local governments, and water systems to compile the report.