The Knoxville Police Department is reminding citizens to keep grass clippings off of the street. 

According to the department, if you sweep your clippings onto the street grass clippings can cause bacteria growth in receiving water bodies, legal penalties, a storm water system clog which can lead to flooding, safety hazards for motorists, and pesticides and chemicals to runoff into storm water drains causing more filtration needs. Some benefits of keeping clippings in your lawn can be that the clippings act as a natural mulch which helps conserve soil moisture preventing your lawn from drought stress, and your lawn will recycle the nutrients your lawn needs to stay healthy. 

For city code regarding grass clippings you can follow this link.