Wet Weather Groundwater Determinations & Percolation Testing for 2022 Season

Percolation testing is open in all areas. Groundwater determinations are open in Cloverdale, Healdsburg, Petaluma, Santa Rosa, Sebastopol, and Sonoma areas. Visit our wet weather testing season web page for more information.

Rainfall totals data and/or testing dates are valid as of April 17, 2022, and can be viewed at Permit Sonoma's Wet Weather Groundwater Determinations & Percolation Testing webpage.