The City of Berkeley says:
Street Sweeping: Residential street sweeping is a City service that not only beautifies our streets and community by removing litter and debris, but protects our environment and keeps the storm drain system from clogging. Street sweeping reduces the pollutant load (leaves, pet/animal debris, heavy metals, oils, grease, sediment, etc.) to the Bay. In addition, material removed by street sweeping will not be able to block lines reducing the amount of flooding during heavy rainfall…
Love your street-sweeping parking tickets!