...S&P Global Ratings has raised its rating to 'A' from 'A-' on Harris County Municipal Utility District (MUD) No. 188, Texas' district's existing general obligation (GO) debt. The outlook is stable. We base the higher rating on continued tax base growth and a reduction in direct and overall debt to levels comparable with peers at the higher rating level, combined with very strong reserves. The rating reflects our opinion of the MUD's: + Access to Houston's deep and diverse economy; + Mature development, limiting any significant future capital needs; and + Very strong finances with a with low property tax rate, which provides revenue-raising flexibility. We believe the rating is somewhat constrained by what we consider the MUD's: + Moderately high, albeit decreasing, overall net debt; and + Highly concentrated tax base. An unlimited-ad valorem tax levied on all taxable property in the MUD secures the bonds. The MUD constructs and maintains water, sewer, and drainage infrastructure on a 477-acre...