Sonoma County Rainfall Totals and Testing Open/Closure Dates Testing

Press release from the Sonoma County Government:

January 8, 2021

Testing has not yet opened for the season.

The information in the table below is updated when open dates change or when new rainfall totals data are collected. The latest updates to the data are displayed in bold below. Data and open/closure information were updated on January 7, 2021.

Area Total Required (inches)Total to Date (inches)GroundwaterPercolationCloverdale20"8.38”ClosedClosedGuerneville25"6.94”ClosedClosedHealdsburg20"5.10” ClosedClosedPetaluma12.5"2.81”ClosedClosedSanta Rosa15"5.53”ClosedClosedSebastopol17.5"5.64” ClosedClosedSonoma15"4.45” ClosedClosed

The Memorandum of Understanding with the State of California Regional Water Quality Control Board allows for wet weather percolation and groundwater testing between January 1 and March 1, and after having received 50% of the average rainfall.

Depth to groundwater determinations can be conducted within ten (10) calendar days following a rainfall of 0.8 inches in a 48 hour period. Sonoma County is divided into 7 geographic areas for this purpose. The amount of rainfall will be posted for each area.

Visit our Inspection Scheduling page to make inspection requests for wet weather percolation/groundwater tests.

Inspection Codes

Wet weather percolation test: 384 Wet weather groundwater test: 386

View inspection codes for the Well & Septic section

• Area Boundary Maps
• Groundwater Table Determinations

This press release was produced by the Sonoma County Government>. The views expressed here are the author’s own.