The 'AAA' rating assigned to the Colorado Water Resources and Power Development Authority's drinking water revenue bonds, series 2006B, is based on the state revolving fund program's ability to meet Standard&Poor's Ratings Services' default-tolerance criteria for a 'AAA' rated program, based on cash flow tests for the combined drinking water and clean water (water pollution control) programs. The rating reflects: Drinking water and water pollution control loans through a surplus matching account; Sizable debt service reserves dedicated to the borrowers' loans, funded at a minimum of maximum annual debt service, coupled with surplus funds at the program level that can be used to cure any loan defaults or reserve deficiencies; and The stable credit quality of the borrowers