S&P Global Ratings affirmed its 'A-1+' commercial paper (CP) rating on Houston Combined Utility Systems (CUS), Texas' series B-4. We also affirmed our 'A-1+' short-term rating on the utility system's CP notes series B-4, based on Houston's transparency and financial reporting, as well as market access, which, in our view, is excellent. This would likely allow the city sufficient ability--even under a compressed timeline--to issue refunding bonds. Providing an additional hedge against extraordinary risk is the CUS' robust liquidity. The series B-4 notes are additionally secured by a revolving credit agreement with State Street Bank and Trust Co. For additional information on Houston Combined Utility Systems, see the rationale, published July 26, 2016, on RatingsDirect. We understand the CP program