All rankings
California · California (CIWQS)
Sunnyvale City
B
Seldom reaches water
Reported events
142
Total volume
142K gal
Reached waterways
11 (8%)
Reporting since
2007
What caused the overflows
Root Intrusion
85
Grease / FOG
37
Equipment Failure
10
Other / Unknown
10
Reported overflow events (showing 142 of 142)
| Date | Volume | Cause | Reached water | Receiving water |
|---|---|---|---|---|
| Apr 7, 2026 | 2K gal | Grease / FOG | — | — |
| Sep 10, 2025 | 840 gal | Root Intrusion | — | — |
| Sep 3, 2025 | 50 gal | Root Intrusion | — | — |
| Sep 3, 2025 | 50 gal | Root Intrusion | — | — |
| Jul 16, 2025 | 55 gal | Root Intrusion | — | — |
| Mar 6, 2025 | 531 gal | Equipment Failure | — | — |
| Nov 10, 2024 | 600 gal | Grease / FOG | — | — |
| May 3, 2024 | 165 gal | Grease / FOG | — | — |
| Mar 23, 2024 | 850 gal | Root Intrusion | — | — |
| Mar 20, 2024 | 80 gal | Other / Unknown | — | — |
| Dec 31, 2023 | 165 gal | Grease / FOG | — | — |
| Oct 27, 2023 | 960 gal | Root Intrusion | — | — |
| Oct 8, 2023 | 110 gal | Grease / FOG | — | — |
| Mar 16, 2023 | 600 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Sep 22, 2022 | 220 gal | Root Intrusion | — | Paved Surface;Separate Storm Drain;Street/Curb and Gutter |
| Aug 23, 2022 | 2K gal | Grease / FOG | — | Separate Storm Drain;Street/Curb and Gutter |
| Aug 19, 2022 | 30 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Jul 19, 2022 | 2K gal | Equipment Failure | — | Paved Surface;Street/Curb and Gutter |
| Apr 11, 2022 | 55 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Apr 5, 2022 | 110 gal | Equipment Failure | — | Paved Surface;Street/Curb and Gutter |
| Mar 2, 2022 | 20 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Feb 17, 2022 | 10 gal | Grease / FOG | — | Paved Surface;Street/Curb and Gutter |
| Jan 18, 2022 | 1K gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Jan 6, 2022 | 40 gal | Equipment Failure | — | Paved Surface;Street/Curb and Gutter |
| Oct 3, 2021 | 4K gal | Grease / FOG | — | Paved Surface;Street/Curb and Gutter |
| Jul 25, 2021 | 20 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Mar 5, 2021 | 50 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Feb 28, 2021 | 400 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Dec 5, 2020 | 1K gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Oct 30, 2020 | 1K gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Apr 18, 2020 | 475 gal | Root Intrusion | — | Street/Curb and Gutter |
| Apr 8, 2020 | 79 gal | Root Intrusion | — | Street/Curb and Gutter |
| Mar 19, 2020 | 1K gal | Grease / FOG | — | Paved Surface;Street/Curb and Gutter |
| Mar 17, 2020 | 1K gal | Grease / FOG | — | Paved Surface;Street/Curb and Gutter |
| Dec 7, 2019 | 2K gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Nov 8, 2019 | 1K gal | Root Intrusion | — | Other (specify below);Paved Surface |
| Sep 2, 2019 | 3K gal | Grease / FOG | — | Paved Surface |
| Aug 21, 2019 | 55 gal | Root Intrusion | — | Other (specify below) |
| May 25, 2019 | 600 gal | Root Intrusion | — | Paved Surface |
| Feb 18, 2019 | 550 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Jan 2, 2019 | 25 gal | Other / Unknown | — | Paved Surface;Street/Curb and Gutter |
| Dec 20, 2018 | 700 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Oct 5, 2018 | 1K gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Apr 11, 2018 | 2K gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Mar 21, 2018 | 10 gal | Grease / FOG | — | Paved Surface |
| Feb 19, 2018 | 15 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Nov 8, 2017 | 5 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Oct 10, 2017 | 1K gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Apr 15, 2017 | 3K gal | Root Intrusion | — | Paved Surface |
| Mar 27, 2017 | 110 gal | Root Intrusion | — | Paved Surface |
| Feb 21, 2017 | 1K gal | Grease / FOG | — | Paved Surface |
| Jan 31, 2017 | 25 gal | Grease / FOG | — | Paved Surface |
| Jul 25, 2016 | 10 gal | Equipment Failure | — | Paved Surface |
| Jul 11, 2016 | 5 gal | Root Intrusion | — | Street/Curb and Gutter |
| Feb 20, 2016 | 750 gal | Root Intrusion | — | Paved Surface |
| Jun 11, 2015 | 20 gal | Root Intrusion | — | Street/Curb and Gutter |
| Feb 15, 2015 | 900 gal | Root Intrusion | — | Paved Surface |
| Feb 9, 2015 | 875 gal | Root Intrusion | — | Paved Surface |
| Dec 29, 2014 | 75 gal | Root Intrusion | — | Paved Surface |
| Nov 26, 2014 | 425 gal | Grease / FOG | — | Paved Surface |
| Sep 19, 2014 | 1K gal | Root Intrusion | — | Separate Storm Drain;Street/Curb and Gutter |
| Apr 17, 2014 | 80 gal | Root Intrusion | — | Street/Curb and Gutter |
| Apr 8, 2014 | 75 gal | Root Intrusion | — | Street/Curb and Gutter |
| Mar 29, 2014 | 275 gal | Root Intrusion | — | Paved Surface;Separate Storm Drain;Street/Curb and Gutter |
| Mar 22, 2014 | 300 gal | Root Intrusion | — | Paved Surface;Separate Storm Drain;Street/Curb and Gutter |
| Mar 19, 2014 | 135 gal | Grease / FOG | — | Paved Surface;Separate Storm Drain;Street/Curb and Gutter |
| Sep 9, 2013 | 587 gal | Root Intrusion | — | Paved Surface;Separate Storm Drain;Street/Curb and Gutter |
| Jul 9, 2013 | 96 gal | Grease / FOG | — | Other paved surface;Street/curb and gutter;Unpaved surface |
| Jul 6, 2013 | 374 gal | Root Intrusion | — | Street/curb and gutter |
| Jun 24, 2013 | 2K gal | Grease / FOG | — | Separate storm drain;Street/curb and gutter |
| Jun 20, 2013 | 330 gal | Root Intrusion | — | Separate storm drain;Street/curb and gutter |
| Jun 17, 2013 | 10 gal | Root Intrusion | — | Street/curb and gutter |
| Apr 30, 2013 | 1K gal | Root Intrusion | — | Street/curb and gutter |
| Mar 23, 2013 | 300 gal | Root Intrusion | — | Separate storm drain;Street/curb and gutter |
| Feb 28, 2013 | 30 gal | Grease / FOG | — | Street/curb and gutter |
| Feb 8, 2013 | 50 gal | Root Intrusion | — | Street/curb and gutter |
| Feb 5, 2013 | 255 gal | Root Intrusion | — | Separate storm drain;Street/curb and gutter |
| Jan 27, 2013 | 10 gal | Root Intrusion | — | Street/curb and gutter;Unpaved surface |
| Jan 25, 2013 | 40 gal | Root Intrusion | — | Street/curb and gutter;Unpaved surface |
| Jan 13, 2013 | 575 gal | Equipment Failure | — | Street/curb and gutter |
| Nov 26, 2012 | 725 gal | Grease / FOG | — | Other paved surface;Separate storm drain;Street/curb and gutter |
| Sep 13, 2012 | 1K gal | Grease / FOG | — | Building or structure;Separate storm drain;Street/curb and gutter |
| Aug 22, 2012 | 100 gal | Equipment Failure | — | Street/curb and gutter |
| Apr 19, 2012 | 3K gal | Grease / FOG | — | Separate storm drain;Street/curb and gutter |
| Apr 4, 2012 | 250 gal | Grease / FOG | — | Building or structure;Other paved surface |
| Apr 4, 2012 | 40 gal | Root Intrusion | — | Separate storm drain;Street/curb and gutter |
| Jan 15, 2012 | 225 gal | Grease / FOG | — | Separate storm drain;Street/curb and gutter |
| Jan 10, 2012 | 35 gal | Root Intrusion | — | Street/curb and gutter |
| Jan 5, 2012 | 25 gal | Root Intrusion | — | Street/curb and gutter |
| Nov 21, 2011 | 500 gal | Root Intrusion | — | Separate storm drain;Street/curb and gutter |
| Nov 19, 2011 | 700 gal | Grease / FOG | — | Street/curb and gutter |
| Nov 8, 2011 | 250 gal | Other / Unknown | — | Separate storm drain;Street/curb and gutter |
| Oct 30, 2011 | 3K gal | Root Intrusion | — | Separate storm drain;Street/curb and gutter |
| Oct 12, 2011 | 2K gal | Other / Unknown | Yes | Other (specify below) |
| Oct 7, 2011 | 240 gal | Grease / FOG | — | Street/curb and gutter |
| Sep 18, 2011 | 55 gal | Root Intrusion | — | Street/curb and gutter |
| Aug 16, 2011 | 50 gal | Root Intrusion | — | Street/curb and gutter |
| Jul 16, 2011 | 690 gal | Other / Unknown | Yes | Separate storm drain;Street/curb and gutter;Other (specify below) |
| Jul 15, 2011 | 50 gal | Other / Unknown | — | Unpaved surface |
| Apr 11, 2011 | 120 gal | Equipment Failure | — | Separate storm drain;Other (specify below) |
| Feb 25, 2011 | 20 gal | Other / Unknown | — | Unpaved surface |
| Feb 4, 2011 | 20 gal | Root Intrusion | — | Street/curb and gutter |
| Jan 27, 2011 | 3K gal | Grease / FOG | Yes | Other (specify below) |
| Jan 14, 2011 | 50 gal | Root Intrusion | — | Street/curb and gutter |
| Dec 11, 2010 | 100 gal | Root Intrusion | — | Street/curb and gutter |
| Oct 23, 2010 | 55 gal | Root Intrusion | — | Street/curb and gutter |
| Sep 24, 2010 | 25K gal | Grease / FOG | Yes | Separate storm drain;Other (specify below) |
| Sep 18, 2010 | 4K gal | Grease / FOG | — | Storm drain |
| Sep 16, 2010 | 10 gal | Root Intrusion | — | Street/curb and gutter |
| Jun 16, 2010 | 2K gal | Root Intrusion | — | Storm drain;Street/curb and gutter |
| May 31, 2010 | 25 gal | Root Intrusion | — | Street/curb and gutter |
| May 1, 2010 | 300 gal | Grease / FOG | — | Street/curb and gutter |
| Apr 16, 2010 | 280 gal | Grease / FOG | Yes | Storm drain;Surface water |
| Apr 9, 2010 | 2K gal | Root Intrusion | Yes | Storm drain;Surface water |
| Apr 4, 2010 | 325 gal | Other / Unknown | — | Street/curb and gutter |
| Mar 31, 2010 | 15 gal | Root Intrusion | — | Street/curb and gutter |
| Mar 7, 2010 | 50 gal | Grease / FOG | — | Street/curb and gutter |
| Feb 7, 2010 | 5 gal | Root Intrusion | — | Street/curb and gutter |
| Jan 25, 2010 | 110 gal | Grease / FOG | — | Street/curb and gutter |
| Jan 7, 2010 | 5 gal | Root Intrusion | — | Street/curb and gutter |
| Dec 21, 2009 | 3K gal | Root Intrusion | — | Storm drain;Street/curb and gutter |
| Dec 13, 2009 | 400 gal | Root Intrusion | — | Storm drain;Street/curb and gutter |
| Dec 5, 2009 | 375 gal | Root Intrusion | — | Storm drain;Street/curb and gutter;Unpaved surface |
| Nov 21, 2009 | 375 gal | Grease / FOG | — | Storm drain;Street/curb and gutter |
| Oct 24, 2009 | 375 gal | Root Intrusion | — | Other paved surface;Storm drain;Street/curb and gutter |
| Oct 21, 2009 | 250 gal | Root Intrusion | — | Other paved surface;Storm drain |
| Sep 26, 2009 | 50 gal | Root Intrusion | — | Storm drain;Street/curb and gutter |
| Aug 26, 2009 | 215 gal | Root Intrusion | Yes | Separate storm drain;Other (specify below) |
| Jul 3, 2009 | 2K gal | Root Intrusion | Yes | Surface water |
| Jun 25, 2009 | 60 gal | Root Intrusion | — | Street/curb and gutter |
| Apr 29, 2009 | 26 gal | Grease / FOG | — | Other paved surface |
| Jan 28, 2009 | 450 gal | Grease / FOG | — | Separate storm drain;Street/curb and gutter |
| Jan 11, 2009 | 50 gal | Grease / FOG | — | Street/curb and gutter |
| Dec 15, 2008 | 20 gal | Root Intrusion | — | Street/curb and gutter |
| Oct 28, 2008 | 650 gal | Root Intrusion | Yes | Surface water |
| Oct 6, 2008 | 5 gal | Other / Unknown | — | Other paved surface |
| Jun 24, 2008 | 9 gal | Other / Unknown | — | Other paved surface |
| Oct 27, 2007 | 30K gal | Equipment Failure | Yes | Surface water |
| Aug 29, 2007 | 65 gal | Root Intrusion | — | Street/curb and gutter |
| Aug 14, 2007 | 5 gal | Root Intrusion | — | Unpaved surface |
| Jun 4, 2007 | 500 gal | Equipment Failure | Yes | Unpaved surface;Other (specify below) |
| May 6, 2007 | 4K gal | Root Intrusion | — | Storm drain |
Source: California (CIWQS). Volumes are utility-reported estimates. Some events lack precise coordinates or volumes.