NEW YORK (Standard&Poor's) Dec. 3, 2012--Standard&Poor's Ratings Services has assigned its 'A-' rating to the City of Wamego, Kan.'s electric system revenue bonds, series 2012. The outlook is stable. "The rating reflects our view of a small service area and budget that constrain financial flexibility, financial statements that are cash-based and do not conform with generally accepted accounting principles, modest customer concentration; slightly above-average rates coupled with county incomes that are slightly below the state average, and weak bond provisions," said Standard&Poor's credit analyst Jeffrey Panger. Characteristics that we view as credit strengths include the following: A predominately residential service area, and participation in the broader Topeka and Manhattan, Kan., economy, which have below-average