50 ILCS 815/2
Any county or municipality may, by ordinance, adopt requirements that all applications for building permits contain a statement that such buildings and appurtenances connected therewith include facilities for the orderly runoff or retention of rain and melting snow. Such facilities may include, but not be limited to: retention ponds, retention tanks, pools located on and a part of the roof of buildings, permeable pavements and such other facilities as may be suitable. Such plans shall include a signed statement issued by a licensed civil engineer that the plans include facilities adequate to prevent harmful runoff. The governing body of the county or municipality shall determine rain and snowfalls taking into consideration such factors as the permeability and water absorbing quality of the soil and adequacy of existing water-ways.
50 ILCS 815/2