S&P Global Ratings raised its ratings by one notch to 'AA' on the senior subordinate-lien bonds and to 'AA-' on the third subordinate-lien series 2012 revenue bonds issued by Nashville&Davidson County Metropolitan Government, Tenn. for its water and sewer utility system, which does business as Metro Water Services (MWS). We also assigned a 'AA' rating to MWS' series 2017A water and sewer revenue green bonds and series 2017B revenue bonds. Both series are being issued as senior subordinate-lien bonds; the senior subordinate lien is the second in priority of three existing liens and serves as the working lien. The rating reflects, in our opinion, the combination of an extremely strong enterprise risk profile and a very strong financial