Standard&Poor's Ratings Services raised its long-term rating on Huntsville, Ala.'s water system revenue warrants outstanding to 'AAA' from 'AA+'. The outlook is stable. The upgrade reflects what we view as continued strong economic development within the system's service area, strong management with demonstrated rate increases and planning procedures, the system's emerging role as a regional water provider, and improving liquidity levels. The rating reflects Standard&Poor's opinion of the system's: Expanding customer base, which is characterized by above-average wealth and income levels; Exceptionally low water rates compared with the rates of regional and national peers, resulting in tremendous rate-setting flexibility; Solid financial performance and position, which has generated what we see as sound debt service coverage levels;