Tinley Park, IL Environmental Rules: Grading & Drainage (2026)

Tinley Park's building and stormwater codes prohibit altering lot grading in ways that redirect water onto neighboring properties or interfere with established drainage patterns. Most residential lots in the Village's subdivisions were platted with a specific drainage scheme (swales along rear or side lot lines) that must be preserved. Adding significant fill, building retaining walls, or regrading large areas requires a grading permit and drainage review. Sump pump discharge lines must terminate on the property owner's own lawn (at least 5 feet from the foundation and not closer than 5 to 10 feet from property lines, depending on conditions) or connect to the storm sewer with Village approval. Sump pump discharge to the sanitary sewer is prohibited under MWRD rules and contributes to sewer overflows. Downspouts from roofs should discharge to splash blocks on lawns that slope away from the foundation. Downspouts connected directly to the sanitary sewer (through old tile or clandestine connections) are prohibited and must be disconnected. Illinois follows a reasonable use rule for surface water: a landowner may not unreasonably divert or accumulate water to a neighbor's detriment.