All rankings
California · California (CIWQS)
Sonora
C
Often reaches water
Reported events
212
Total volume
227K gal
Reached waterways
38 (18%)
Reporting since
2007
What caused the overflows
Root Intrusion
99
Equipment Failure
54
Grease / FOG
32
Other / Unknown
27
Reported overflow events (showing 200 of 212)
| Date | Volume | Cause | Reached water | Receiving water |
|---|---|---|---|---|
| May 27, 2026 | 371 gal | Root Intrusion | Yes | Lake Don Pedro |
| Feb 2, 2026 | 15K gal | Equipment Failure | — | Spill did not enter a body of water. |
| Jan 21, 2026 | 622 gal | Grease / FOG | Yes | Sullivan Creek |
| Dec 9, 2025 | 55 gal | Root Intrusion | — | — |
| Dec 4, 2025 | 355 gal | Equipment Failure | — | — |
| Jan 29, 2025 | 168 gal | Other / Unknown | Yes | Sonora Creek |
| Jan 23, 2025 | 460 gal | Equipment Failure | Yes | Sonora creek |
| Aug 1, 2024 | 271 gal | Root Intrusion | — | — |
| May 23, 2024 | 1K gal | Equipment Failure | Yes | Don Pedro Reservoir |
| Apr 7, 2024 | 832 gal | Equipment Failure | Yes | Don Pedro Reservoir |
| Feb 15, 2024 | 108 gal | Equipment Failure | — | — |
| Apr 11, 2023 | 15 gal | Equipment Failure | — | Paved Surface;Unpaved surface |
| Apr 5, 2023 | 19 gal | Equipment Failure | — | Paved Surface;Unpaved surface |
| Feb 3, 2023 | 30 gal | Root Intrusion | — | Separate Storm Drain;Unpaved surface |
| Dec 12, 2022 | 9K gal | Grease / FOG | Yes | Separate Storm Drain;Surface Water |
| Sep 12, 2022 | 279 gal | Root Intrusion | — | Separate Storm Drain;Unpaved surface |
| May 19, 2022 | 191 gal | Equipment Failure | — | Paved Surface;Separate Storm Drain;Street/Curb and Gutter |
| Jan 15, 2022 | 148 gal | Other / Unknown | — | Paved Surface;Unpaved surface |
| Jan 14, 2022 | 672 gal | Root Intrusion | — | Paved Surface;Separate Storm Drain;Unpaved surface |
| Nov 16, 2021 | 648 gal | Equipment Failure | — | Paved Surface;Unpaved surface |
| Oct 29, 2021 | 25 gal | Root Intrusion | — | Separate Storm Drain |
| Oct 26, 2021 | 100 gal | Equipment Failure | — | Unpaved surface |
| Oct 23, 2021 | 25 gal | Equipment Failure | — | Paved Surface;Separate Storm Drain |
| Aug 15, 2021 | 179 gal | Grease / FOG | — | Unpaved surface |
| Jan 18, 2021 | 270 gal | Equipment Failure | — | Paved Surface;Unpaved surface |
| Dec 19, 2020 | 25 gal | Root Intrusion | — | Paved Surface |
| Dec 19, 2020 | 65 gal | Equipment Failure | — | Separate Storm Drain |
| Sep 15, 2020 | 20 gal | Grease / FOG | — | Paved Surface;Unpaved surface |
| Feb 10, 2020 | 1K gal | Equipment Failure | — | Unpaved surface |
| Jan 13, 2020 | 60 gal | Equipment Failure | — | Unpaved surface |
| Nov 7, 2019 | 80 gal | Equipment Failure | — | Unpaved surface |
| Oct 7, 2019 | 20 gal | Grease / FOG | — | Street/Curb and Gutter |
| Jul 2, 2019 | 400 gal | Equipment Failure | — | Unpaved surface |
| Mar 25, 2019 | 2K gal | Grease / FOG | — | Unpaved surface |
| Dec 24, 2018 | 240 gal | Root Intrusion | — | Unpaved surface |
| Nov 17, 2018 | 400 gal | Root Intrusion | — | Separate Storm Drain;Unpaved surface |
| Nov 3, 2018 | 3 gal | Root Intrusion | — | Paved Surface |
| Sep 4, 2018 | 1K gal | Root Intrusion | — | Unpaved surface |
| Mar 24, 2018 | 78 gal | Root Intrusion | — | Unpaved surface |
| Dec 23, 2017 | 60 gal | Equipment Failure | — | Building or Structure;Paved Surface |
| Dec 17, 2017 | 30 gal | Equipment Failure | — | Paved Surface;Separate Storm Drain |
| Dec 10, 2017 | 15 gal | Equipment Failure | — | Separate Storm Drain |
| Oct 27, 2017 | 100 gal | Grease / FOG | — | Unpaved surface |
| Feb 13, 2017 | 5 gal | Equipment Failure | Yes | Separate Storm Drain |
| Jan 16, 2017 | 100 gal | Equipment Failure | — | Separate Storm Drain |
| Dec 24, 2016 | 5 gal | Root Intrusion | — | Paved Surface |
| Sep 9, 2016 | 100 gal | Root Intrusion | — | Paved Surface;Separate Storm Drain;Unpaved surface |
| Jul 29, 2016 | 210 gal | Other / Unknown | — | Paved Surface;Separate Storm Drain |
| Apr 14, 2016 | 80 gal | Other / Unknown | — | Separate Storm Drain |
| Feb 9, 2016 | 200 gal | Root Intrusion | — | Unpaved surface |
| Jan 13, 2016 | 457 gal | Root Intrusion | — | Separate Storm Drain |
| Nov 11, 2015 | 42 gal | Grease / FOG | — | Paved Surface;Separate Storm Drain |
| Oct 14, 2015 | 10 gal | Grease / FOG | — | Paved Surface |
| Sep 14, 2015 | 20 gal | Equipment Failure | — | Unpaved surface |
| Sep 13, 2015 | 100 gal | Equipment Failure | — | Separate Storm Drain |
| Jul 24, 2015 | 10 gal | Root Intrusion | — | Paved Surface |
| May 18, 2015 | 200 gal | Equipment Failure | — | Unpaved surface |
| Feb 22, 2015 | 50 gal | Root Intrusion | — | Unpaved surface |
| Feb 2, 2015 | 50 gal | Root Intrusion | — | Paved Surface;Unpaved surface |
| Nov 24, 2014 | 50 gal | Root Intrusion | — | Separate Storm Drain |
| Nov 3, 2014 | 20 gal | Root Intrusion | — | Separate Storm Drain |
| Sep 30, 2014 | 80 gal | Root Intrusion | — | Unpaved surface |
| Apr 16, 2014 | 70 gal | Root Intrusion | — | Separate Storm Drain |
| Feb 16, 2014 | 50 gal | Root Intrusion | — | Unpaved surface |
| Jan 6, 2014 | 5 gal | Equipment Failure | — | Paved Surface |
| Nov 11, 2013 | 40 gal | Root Intrusion | — | Unpaved surface |
| Aug 13, 2013 | 400 gal | Root Intrusion | — | Unpaved surface |
| Jul 12, 2013 | 70 gal | Root Intrusion | — | Other paved surface |
| Apr 10, 2013 | 300 gal | Root Intrusion | Yes | Surface water |
| Mar 13, 2013 | 20 gal | Root Intrusion | — | Separate storm drain |
| Feb 3, 2013 | 20 gal | Equipment Failure | — | Other paved surface |
| Jan 9, 2013 | 30 gal | Other / Unknown | Yes | Surface water |
| Dec 20, 2012 | 400 gal | Root Intrusion | — | Unpaved surface |
| Nov 29, 2012 | 85 gal | Grease / FOG | — | Unpaved surface |
| Nov 24, 2012 | 50 gal | Root Intrusion | — | Other paved surface;Unpaved surface |
| Nov 23, 2012 | 50 gal | Root Intrusion | — | Unpaved surface |
| Nov 8, 2012 | 140 gal | Equipment Failure | Yes | Surface water |
| Aug 23, 2012 | 2K gal | Root Intrusion | Yes | Unpaved surface |
| Aug 8, 2012 | 65 gal | Equipment Failure | Yes | Surface water |
| Jul 5, 2012 | 5 gal | Root Intrusion | — | Street/curb and gutter |
| Apr 1, 2012 | 20 gal | Root Intrusion | — | Unpaved surface |
| Mar 23, 2012 | 3K gal | Grease / FOG | Yes | Surface water |
| Feb 19, 2012 | 50 gal | Other / Unknown | — | Separate storm drain |
| Feb 2, 2012 | 50 gal | Equipment Failure | Yes | Surface water |
| Oct 29, 2011 | 200 gal | Other / Unknown | Yes | Surface water |
| Oct 21, 2011 | 30 gal | Other / Unknown | — | Unpaved surface |
| Oct 14, 2011 | 70 gal | Root Intrusion | — | Separate storm drain |
| Oct 13, 2011 | 50 gal | Root Intrusion | — | Separate storm drain |
| Oct 11, 2011 | 200 gal | Root Intrusion | Yes | Surface water |
| Jul 1, 2011 | 40K gal | Grease / FOG | — | Unpaved surface |
| Apr 22, 2011 | 175 gal | Grease / FOG | — | Separate storm drain |
| Apr 19, 2011 | 150 gal | Other / Unknown | Yes | Surface water |
| Apr 17, 2011 | 53K gal | Equipment Failure | Yes | Unpaved surface |
| Apr 4, 2011 | 20 gal | Root Intrusion | — | Separate storm drain |
| Mar 4, 2011 | 15 gal | Root Intrusion | — | Other paved surface |
| Feb 28, 2011 | 750 gal | Equipment Failure | Yes | Other (specify below) |
| Feb 17, 2011 | 700 gal | Grease / FOG | Yes | Separate storm drain |
| Feb 12, 2011 | 300 gal | Other / Unknown | — | Unpaved surface |
| Feb 9, 2011 | 50 gal | Other / Unknown | — | Unpaved surface |
| Jan 31, 2011 | 350 gal | Other / Unknown | Yes | Unpaved surface |
| Jan 29, 2011 | 60 gal | Root Intrusion | — | Other paved surface |
| Jan 18, 2011 | 30 gal | Equipment Failure | — | Street/curb and gutter;Unpaved surface |
| Jan 18, 2011 | 1 gal | Root Intrusion | — | Unpaved surface |
| Jan 17, 2011 | 75 gal | Root Intrusion | Yes | Separate storm drain |
| Jan 12, 2011 | 15 gal | Equipment Failure | — | Unpaved surface |
| Dec 30, 2010 | 15 gal | Other / Unknown | — | Street/curb and gutter |
| Dec 6, 2010 | 30 gal | Equipment Failure | — | Unpaved surface |
| Nov 25, 2010 | 60 gal | Grease / FOG | — | Other paved surface |
| Nov 17, 2010 | 50 gal | Equipment Failure | — | Unpaved surface |
| Nov 13, 2010 | 60 gal | Root Intrusion | — | Other paved surface |
| Oct 19, 2010 | 30 gal | Grease / FOG | — | Other paved surface;Storm drain |
| Sep 30, 2010 | 250 gal | Other / Unknown | — | Storm drain;Unpaved surface |
| Aug 26, 2010 | 265 gal | Grease / FOG | Yes | Surface water |
| Jul 13, 2010 | 100 gal | Grease / FOG | — | Storm drain |
| Jul 6, 2010 | 40 gal | Equipment Failure | — | Unpaved surface |
| Jun 6, 2010 | 820 gal | Root Intrusion | — | Storm drain |
| Jun 5, 2010 | 700 gal | Grease / FOG | — | Unpaved surface |
| Jun 5, 2010 | 700 gal | Grease / FOG | — | Unpaved surface |
| May 18, 2010 | 20 gal | Root Intrusion | — | Other paved surface |
| May 12, 2010 | 100 gal | Equipment Failure | — | Other paved surface;Unpaved surface |
| May 9, 2010 | 15 gal | Root Intrusion | — | Unpaved surface |
| May 5, 2010 | 120 gal | Equipment Failure | — | Unpaved surface |
| Apr 24, 2010 | 150 gal | Grease / FOG | — | Unpaved surface |
| Apr 8, 2010 | 20 gal | Root Intrusion | — | Other paved surface |
| Mar 26, 2010 | 100 gal | Other / Unknown | — | Unpaved surface |
| Mar 11, 2010 | 50 gal | Root Intrusion | — | Unpaved surface |
| Feb 20, 2010 | 200 gal | Equipment Failure | — | Unpaved surface |
| Feb 17, 2010 | 150 gal | Grease / FOG | Yes | Surface water |
| Feb 15, 2010 | 15 gal | Other / Unknown | — | Other paved surface;Unpaved surface |
| Jan 9, 2010 | 25 gal | Equipment Failure | — | Unpaved surface |
| Jan 7, 2010 | 250 gal | Root Intrusion | — | Unpaved surface |
| Jan 3, 2010 | 128 gal | Root Intrusion | — | Unpaved surface |
| Dec 14, 2009 | 20 gal | Root Intrusion | — | Other paved surface |
| Dec 13, 2009 | 25 gal | Root Intrusion | — | Unpaved surface |
| Nov 22, 2009 | 5 gal | Other / Unknown | — | Unpaved surface |
| Nov 17, 2009 | 50 gal | Root Intrusion | — | Other paved surface;Street/curb and gutter;Unpaved surface |
| Nov 17, 2009 | 30 gal | Root Intrusion | — | Other paved surface;Unpaved surface |
| Oct 31, 2009 | 250 gal | Root Intrusion | — | Storm drain |
| Oct 3, 2009 | 2 gal | Root Intrusion | — | Unpaved surface |
| Oct 2, 2009 | 200 gal | Root Intrusion | — | Storm drain |
| Sep 23, 2009 | 15 gal | Root Intrusion | — | Unpaved surface |
| Sep 18, 2009 | 60 gal | Root Intrusion | — | Other paved surface;Unpaved surface |
| Sep 16, 2009 | 50 gal | Grease / FOG | — | Unpaved surface |
| Aug 19, 2009 | 20 gal | Root Intrusion | — | Unpaved surface |
| Aug 17, 2009 | 300 gal | Equipment Failure | — | Unpaved surface |
| Aug 14, 2009 | 55 gal | Root Intrusion | — | Unpaved surface |
| Aug 7, 2009 | 10 gal | Other / Unknown | — | Unpaved surface |
| Aug 4, 2009 | 20 gal | Root Intrusion | — | Other paved surface;Separate storm drain |
| Jun 27, 2009 | 30 gal | Other / Unknown | — | Other paved surface;Street/curb and gutter |
| Jun 25, 2009 | 800 gal | Equipment Failure | — | Storm drain;Unpaved surface |
| Jun 17, 2009 | 800 gal | Root Intrusion | — | Unpaved surface |
| Jun 10, 2009 | 900 gal | Other / Unknown | Yes | Storm drain |
| Jun 9, 2009 | 10 gal | Equipment Failure | — | Other paved surface |
| Jun 2, 2009 | 100 gal | Equipment Failure | Yes | Surface water |
| May 31, 2009 | 180 gal | Grease / FOG | — | Unpaved surface |
| May 11, 2009 | 600 gal | Root Intrusion | Yes | Other paved surface;Storm drain;Street/curb and gutter;Surface water;Unpaved surface |
| May 10, 2009 | 50 gal | Root Intrusion | — | Unpaved surface |
| Apr 29, 2009 | 7 gal | Root Intrusion | — | Other paved surface;Unpaved surface |
| Apr 25, 2009 | 3 gal | Root Intrusion | — | Unpaved surface |
| Apr 17, 2009 | 150 gal | Equipment Failure | — | Unpaved surface |
| Apr 16, 2009 | 1 gal | Equipment Failure | — | Unpaved surface |
| Mar 30, 2009 | 600 gal | Other / Unknown | Yes | Separate storm drain;Surface water |
| Feb 19, 2009 | 35 gal | Root Intrusion | — | Other paved surface;Storm drain;Street/curb and gutter |
| Feb 10, 2009 | 500 gal | Root Intrusion | Yes | Surface water;Unpaved surface |
| Feb 10, 2009 | 200 gal | Grease / FOG | — | Other paved surface;Unpaved surface |
| Feb 8, 2009 | 10 gal | Root Intrusion | — | Other paved surface;Unpaved surface |
| Jan 26, 2009 | 225 gal | Root Intrusion | — | Unpaved surface |
| Jan 20, 2009 | 30 gal | Other / Unknown | — | Unpaved surface |
| Jan 7, 2009 | 300 gal | Equipment Failure | — | Other paved surface;Street/curb and gutter;Unpaved surface |
| Jan 7, 2009 | 200 gal | Equipment Failure | — | Building or structure;Other paved surface;Unpaved surface |
| Jan 6, 2009 | 500 gal | Equipment Failure | — | Other paved surface;Unpaved surface |
| Dec 30, 2008 | 273 gal | Root Intrusion | — | Unpaved surface |
| Dec 28, 2008 | 2K gal | Root Intrusion | Yes | Storm drain;Surface water;Other (specify below) |
| Nov 4, 2008 | 250 gal | Root Intrusion | — | Other paved surface |
| Nov 1, 2008 | 6K gal | Equipment Failure | — | Unpaved surface |
| Oct 3, 2008 | 500 gal | Grease / FOG | Yes | Unpaved surface |
| Sep 30, 2008 | 25 gal | Root Intrusion | — | Other paved surface;Unpaved surface |
| Sep 16, 2008 | 15 gal | Root Intrusion | — | Unpaved surface |
| Sep 10, 2008 | 25 gal | Root Intrusion | — | Street/curb and gutter |
| Sep 7, 2008 | 15 gal | Other / Unknown | — | Other paved surface |
| Aug 27, 2008 | 30 gal | Other / Unknown | — | Unpaved surface |
| Aug 13, 2008 | 20 gal | Root Intrusion | — | Unpaved surface |
| Aug 11, 2008 | 30 gal | Root Intrusion | — | Other paved surface;Separate storm drain;Street/curb and gutter |
| Jul 28, 2008 | 10 gal | Root Intrusion | — | Unpaved surface |
| Jul 26, 2008 | 5 gal | Equipment Failure | — | Street/curb and gutter |
| Jul 19, 2008 | 2K gal | Root Intrusion | — | Other paved surface;Street/curb and gutter;Unpaved surface |
| Jun 25, 2008 | 90 gal | Root Intrusion | Yes | Other paved surface;Storm drain;Surface water |
| Jun 23, 2008 | 275 gal | Grease / FOG | Yes | Other paved surface;Separate storm drain;Surface water |
| Jun 4, 2008 | 80 gal | Root Intrusion | — | Other paved surface;Street/curb and gutter |
| May 27, 2008 | 200 gal | Grease / FOG | — | Other paved surface;Unpaved surface |
| May 5, 2008 | 500 gal | Root Intrusion | — | Other paved surface;Storm drain |
| Apr 27, 2008 | 20 gal | Root Intrusion | — | Other paved surface;Unpaved surface |
| Apr 27, 2008 | 20 gal | Root Intrusion | — | Other paved surface;Unpaved surface |
| Apr 16, 2008 | 900 gal | Root Intrusion | — | Unpaved surface |
| Apr 7, 2008 | 2 gal | Grease / FOG | — | Unpaved surface |
| Feb 24, 2008 | 55K gal | Root Intrusion | Yes | Storm drain;Surface water;Unpaved surface |
| Feb 22, 2008 | 150 gal | Grease / FOG | Yes | Surface water;Unpaved surface |
| Feb 16, 2008 | 800 gal | Root Intrusion | — | Unpaved surface |
| Feb 16, 2008 | 30 gal | Root Intrusion | — | Street/curb and gutter;Unpaved surface |
| Feb 9, 2008 | 700 gal | Root Intrusion | — | Other paved surface;Unpaved surface |
Source: California (CIWQS). Volumes are utility-reported estimates. Some events lack precise coordinates or volumes.