County of Sonoma
Permit Sonoma › Wet Weather Percolation Groundwater Testing
Well and Septic Systems

Wet Weather Groundwater Determinations & Percolation Testing for 2023 Season

Published: January 27, 2023

rain gauge

  • Groundwater determinations have closed in all seven areas. Percolation testing remains open in all seven areas (Cloverdale, Guerneville, Healdsburg, Petaluma, Santa Rosa, Sebastopol, and Sonoma).

  • Rainfall totals data and/or testing dates are valid as of January 27, 2023.

More Information: Wet Weather Groundwater Determinations & Percolation Testing