Climate Change

Climate change is expected to impact future rainfall events in San Mateo County.

Master Plan modeling predicts:

  • The frequency of storm events may increase, meaning a storm that currently has a 10% chance of occurring each year may have a 20% chance in the future.
  • The amount of rain associated with storm events will increase, meaning a storm that used to produce 2.5 inches of rain may produce 3 inches in the future.
  • Sustainable Streets can help mitigate the predicted increases in runoff and play an important role in keeping our streets from flooding.
  • The images show how runoff depth (the amount of rainfall that flows into the storm drainage system) changes for typical storm recurrence frequencies (for example, a 10-year storm has a 10% chance of occurring in any given year, while a 100-year storm has a 1% chance). Areas in darker blue show the greatest predicted increase in runoff depth.