Drainage and source reduction refers to cleaning and maintaining drainage ways and/or eliminating other potential mosquito breeding sites. Breeding sites can include tree holes, tires, buckets, boat covers, etc. Drainage maintenance plays a significant role in Chesapeake's mosquito control efforts because of its importance to source reduction. These efforts include cleaning and re-grading of non-roadside ditches to ensure proper water flow that will reduce the amount of standing water. Source reduction allows the use of biological control measures to be taken instead of chemical control; therefore, benefiting environmental and fiscal concerns.