All rankings
California · California (CIWQS)
West County Wastewater District
D
Frequently reaches water
Reported events
228
Total volume
2.6M gal
Reached waterways
93 (41%)
Reporting since
2007
What caused the overflows
Equipment Failure
98
Other / Unknown
50
Root Intrusion
48
Grease / FOG
26
Rainfall / Flooding
4
Capacity Issue
2
Reported overflow events (showing 200 of 228)
| Date | Volume | Cause | Reached water | Receiving water |
|---|---|---|---|---|
| Feb 26, 2026 | 3K gal | Equipment Failure | — | NA |
| Dec 12, 2025 | 375 gal | Root Intrusion | — | — |
| Oct 2, 2025 | 1K gal | Grease / FOG | Yes | Rheem Creek |
| Sep 21, 2025 | 200 gal | Grease / FOG | Yes | NA |
| Jul 18, 2025 | 95 gal | Root Intrusion | — | — |
| Jun 29, 2025 | 2K gal | Grease / FOG | — | — |
| Apr 21, 2025 | 816 gal | Grease / FOG | Yes | San Pablo Creek |
| Mar 2, 2025 | 3K gal | Root Intrusion | — | — |
| Feb 15, 2025 | 300 gal | Other / Unknown | Yes | Hilltop Lake |
| Feb 4, 2025 | 85K gal | Equipment Failure | Yes | San Pablo Bay |
| Feb 4, 2025 | 400 gal | Equipment Failure | Yes | San Pablo Creek |
| Feb 1, 2025 | 26K gal | Equipment Failure | Yes | San Pablo Creek |
| Nov 22, 2024 | 4K gal | Root Intrusion | Yes | Meeker Slough |
| Oct 14, 2024 | 156 gal | Root Intrusion | — | Rheem Creek |
| Sep 15, 2024 | 220 gal | Equipment Failure | — | — |
| Sep 10, 2024 | 31K gal | Root Intrusion | — | — |
| Aug 19, 2024 | 306 gal | Grease / FOG | — | — |
| Jul 16, 2024 | 32K gal | Equipment Failure | Yes | Rheem Creek |
| Jun 6, 2024 | 3K gal | Grease / FOG | Yes | Unknown |
| Apr 11, 2024 | 1K gal | Equipment Failure | — | — |
| Mar 19, 2024 | 7K gal | Grease / FOG | — | — |
| Mar 18, 2024 | 50 gal | Root Intrusion | — | — |
| Jan 22, 2024 | 20K gal | Equipment Failure | Yes | Rheem Creek |
| Nov 26, 2023 | 440 gal | Grease / FOG | Yes | NA |
| Sep 19, 2023 | 560 gal | Root Intrusion | — | Unknown |
| Aug 29, 2023 | 382K gal | Other / Unknown | — | — |
| Aug 7, 2023 | 3K gal | Equipment Failure | — | — |
| Aug 1, 2023 | 724 gal | Root Intrusion | — | — |
| Jul 26, 2023 | 8K gal | Equipment Failure | Yes | Castro Creek |
| Jul 15, 2023 | 950 gal | Equipment Failure | — | NA |
| Jul 7, 2023 | 4K gal | Equipment Failure | — | — |
| Jun 3, 2023 | 511K gal | Equipment Failure | Yes | San Pablo Creek |
| May 6, 2023 | 8K gal | Equipment Failure | — | Paved Surface |
| Apr 30, 2023 | 10K gal | Equipment Failure | Yes | Surface Water |
| Mar 28, 2023 | 1K gal | Equipment Failure | — | Building or Structure |
| Mar 9, 2023 | 39K gal | Rainfall / Flooding | — | Unpaved surface |
| Mar 9, 2023 | 128K gal | Rainfall / Flooding | Yes | Other (specify below);Separate Storm Drain |
| Mar 1, 2023 | 8K gal | Equipment Failure | Yes | Separate Storm Drain |
| Feb 18, 2023 | 50 gal | Equipment Failure | — | Unpaved surface |
| Dec 14, 2022 | 10K gal | Grease / FOG | Yes | Surface Water |
| Nov 14, 2022 | 14K gal | Grease / FOG | Yes | Separate Storm Drain |
| Oct 30, 2022 | 55 gal | Root Intrusion | — | Unpaved surface |
| Sep 15, 2022 | 50 gal | Root Intrusion | — | Unpaved surface |
| Aug 22, 2022 | 31K gal | Equipment Failure | Yes | Surface Water |
| Aug 18, 2022 | 2K gal | Equipment Failure | Yes | Building or Structure;Separate Storm Drain |
| Apr 15, 2022 | 2K gal | Equipment Failure | Yes | Separate Storm Drain |
| Feb 26, 2022 | 400 gal | Root Intrusion | Yes | Separate Storm Drain |
| Jan 19, 2022 | 13K gal | Other / Unknown | Yes | Surface Water |
| Dec 17, 2021 | 13K gal | Other / Unknown | Yes | Surface Water |
| Nov 3, 2021 | 19K gal | Equipment Failure | — | Other (specify below) |
| Oct 24, 2021 | 111K gal | Root Intrusion | Yes | Separate Storm Drain |
| Oct 24, 2021 | 350 gal | Equipment Failure | — | Unpaved surface |
| Oct 24, 2021 | 450 gal | Root Intrusion | — | Unpaved surface |
| Sep 30, 2021 | 20 gal | Root Intrusion | — | Unpaved surface |
| Sep 11, 2021 | 2K gal | Root Intrusion | Yes | Separate Storm Drain |
| May 4, 2021 | 200 gal | Root Intrusion | — | Unpaved surface |
| Apr 6, 2021 | 718 gal | Equipment Failure | Yes | Surface Water |
| Jan 30, 2021 | 229 gal | Equipment Failure | Yes | Separate Storm Drain |
| Nov 24, 2020 | 44K gal | Other / Unknown | Yes | Other (specify below);Separate Storm Drain |
| Nov 9, 2020 | 675 gal | Equipment Failure | — | Paved Surface;Street/Curb and Gutter |
| Jul 10, 2020 | 750 gal | Root Intrusion | — | Unpaved surface |
| Apr 22, 2020 | 100 gal | Grease / FOG | — | Street/Curb and Gutter |
| Mar 30, 2020 | 193K gal | Equipment Failure | Yes | Surface Water |
| Mar 23, 2020 | 5 gal | Root Intrusion | — | Unpaved surface |
| Feb 5, 2020 | 1K gal | Other / Unknown | — | Unpaved surface |
| Nov 14, 2019 | 14K gal | Equipment Failure | Yes | Drainage Channel;Unpaved surface |
| Oct 28, 2019 | 61K gal | Equipment Failure | Yes | Drainage Channel;Unpaved surface |
| Oct 7, 2019 | 590 gal | Equipment Failure | Yes | Other (specify below);Separate Storm Drain |
| Sep 23, 2019 | 50 gal | Equipment Failure | — | Paved Surface |
| Sep 11, 2019 | 5 gal | Equipment Failure | — | Paved Surface |
| Aug 27, 2019 | 750 gal | Root Intrusion | — | Unpaved surface |
| Aug 22, 2019 | 250 gal | Equipment Failure | — | Unpaved surface |
| Jun 28, 2019 | 50 gal | Grease / FOG | — | Paved Surface |
| May 21, 2019 | 100 gal | Other / Unknown | — | Separate Storm Drain;Street/Curb and Gutter |
| May 8, 2019 | 3K gal | Equipment Failure | Yes | Other (specify below);Separate Storm Drain |
| May 7, 2019 | 2K gal | Equipment Failure | Yes | Separate Storm Drain;Surface Water |
| Apr 17, 2019 | 1K gal | Equipment Failure | — | Separate Storm Drain |
| Mar 30, 2019 | 900 gal | Equipment Failure | Yes | Separate Storm Drain;Unpaved surface |
| Feb 13, 2019 | 2K gal | Rainfall / Flooding | — | Unpaved surface |
| Feb 13, 2019 | 720 gal | Equipment Failure | — | Unpaved surface |
| Feb 13, 2019 | 220 gal | Capacity Issue | — | Building or Structure;Other (specify below) |
| Feb 13, 2019 | 156K gal | Rainfall / Flooding | Yes | Separate Storm Drain |
| Sep 15, 2018 | 220 gal | Equipment Failure | — | Other (specify below) |
| Jun 27, 2018 | 540 gal | Equipment Failure | — | Paved Surface;Unpaved surface |
| Jan 12, 2018 | 10K gal | Equipment Failure | — | Paved Surface;Unpaved surface |
| Dec 1, 2017 | 6K gal | Root Intrusion | — | Unpaved surface |
| Nov 6, 2017 | 30 gal | Other / Unknown | — | Paved Surface |
| Oct 16, 2017 | 588 gal | Equipment Failure | — | Separate Storm Drain |
| Sep 12, 2017 | 18K gal | Equipment Failure | Yes | Separate Storm Drain |
| Jul 14, 2017 | 2K gal | Root Intrusion | Yes | Separate Storm Drain |
| Jul 8, 2017 | 81K gal | Grease / FOG | Yes | Surface Water |
| Jun 13, 2017 | 785 gal | Equipment Failure | Yes | Separate Storm Drain |
| Apr 6, 2017 | 61K gal | Equipment Failure | Yes | Other (specify below);Separate Storm Drain |
| Feb 7, 2017 | 900 gal | Capacity Issue | Yes | Separate Storm Drain |
| Jan 19, 2017 | 2K gal | Other / Unknown | Yes | Separate Storm Drain |
| Jan 16, 2017 | 30 gal | Equipment Failure | Yes | Separate Storm Drain |
| Jan 9, 2017 | 52 gal | Equipment Failure | Yes | Separate Storm Drain |
| Jan 1, 2017 | 870 gal | Equipment Failure | — | Building or Structure;Paved Surface;Unpaved surface |
| Oct 11, 2016 | 30 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter;Unpaved surface |
| Sep 13, 2016 | 108K gal | Equipment Failure | Yes | Other (specify below);Separate Storm Drain |
| Jun 1, 2016 | 50 gal | Other / Unknown | — | Other (specify below);Separate Storm Drain |
| May 16, 2016 | 217 gal | Equipment Failure | Yes | Separate Storm Drain |
| Apr 29, 2016 | 480 gal | Grease / FOG | Yes | Building or Structure;Separate Storm Drain;Street/Curb and Gutter |
| Mar 17, 2016 | 5 gal | Equipment Failure | — | Paved Surface |
| Mar 5, 2016 | 5K gal | Equipment Failure | — | Other (specify below) |
| Feb 16, 2016 | 2K gal | Other / Unknown | — | Unpaved surface |
| Jan 18, 2016 | 6K gal | Root Intrusion | — | Unpaved surface |
| Dec 2, 2015 | 900 gal | Other / Unknown | — | Paved Surface;Separate Storm Drain;Street/Curb and Gutter |
| Nov 23, 2015 | 800 gal | Grease / FOG | Yes | Surface Water |
| Nov 5, 2015 | 10 gal | Root Intrusion | — | Paved Surface |
| Oct 30, 2015 | 300 gal | Equipment Failure | — | Unpaved surface |
| Oct 7, 2015 | 4K gal | Equipment Failure | Yes | Separate Storm Drain |
| Oct 6, 2015 | 8K gal | Grease / FOG | Yes | Separate Storm Drain |
| Sep 8, 2015 | 1K gal | Root Intrusion | — | Unpaved surface |
| Jul 2, 2015 | 3K gal | Equipment Failure | Yes | Separate Storm Drain |
| Jun 20, 2015 | 3K gal | Equipment Failure | Yes | Separate Storm Drain |
| Apr 11, 2015 | 1K gal | Other / Unknown | Yes | Surface Water |
| Jan 28, 2015 | 200 gal | Equipment Failure | — | Unpaved surface |
| Jan 19, 2015 | 190 gal | Equipment Failure | — | Unpaved surface |
| Jan 10, 2015 | 725 gal | Grease / FOG | — | Street/Curb and Gutter |
| Jan 7, 2015 | 450 gal | Equipment Failure | — | Building or Structure;Unpaved surface |
| Dec 27, 2014 | 5K gal | Equipment Failure | Yes | Separate Storm Drain;Surface Water;Unpaved surface |
| Nov 28, 2014 | 4K gal | Equipment Failure | Yes | Separate Storm Drain |
| Oct 24, 2014 | 800 gal | Equipment Failure | Yes | Separate Storm Drain |
| Oct 20, 2014 | 675 gal | Grease / FOG | Yes | Surface Water |
| Oct 14, 2014 | 3K gal | Equipment Failure | — | Other (specify below);Separate Storm Drain |
| Sep 10, 2014 | 3K gal | Root Intrusion | — | Other (specify below) |
| Aug 9, 2014 | 1K gal | Equipment Failure | — | Building or Structure |
| Jul 20, 2014 | 2K gal | Other / Unknown | Yes | Surface Water |
| Jul 8, 2014 | 959 gal | Other / Unknown | — | Other (specify below) |
| Jun 12, 2014 | 615 gal | Root Intrusion | — | Unpaved surface |
| May 31, 2014 | 2K gal | Root Intrusion | Yes | Separate Storm Drain |
| May 26, 2014 | 53K gal | Equipment Failure | Yes | Unpaved surface |
| Apr 27, 2014 | 400 gal | Equipment Failure | Yes | Drainage Channel |
| Feb 13, 2014 | 2K gal | Equipment Failure | Yes | Separate Storm Drain |
| Jan 2, 2014 | 350 gal | Root Intrusion | — | Unpaved surface |
| Dec 27, 2013 | 25 gal | Equipment Failure | — | Unpaved surface |
| Nov 27, 2013 | 5 gal | Equipment Failure | — | Paved Surface |
| Nov 25, 2013 | 15K gal | Equipment Failure | Yes | Separate Storm Drain |
| Oct 27, 2013 | 621 gal | Equipment Failure | — | Street/Curb and Gutter;Surface Water |
| Oct 12, 2013 | 5 gal | Equipment Failure | — | Unpaved surface |
| Oct 8, 2013 | 30 gal | Root Intrusion | — | Unpaved surface |
| Oct 3, 2013 | 4K gal | Grease / FOG | Yes | Separate Storm Drain |
| Sep 20, 2013 | 610 gal | Equipment Failure | Yes | Separate Storm Drain |
| Sep 18, 2013 | 60 gal | Equipment Failure | — | Building or Structure;Unpaved surface |
| Sep 14, 2013 | 2K gal | Other / Unknown | — | Building or Structure |
| Aug 4, 2013 | 5K gal | Other / Unknown | Yes | Separate Storm Drain |
| Jun 10, 2013 | 2K gal | Other / Unknown | — | Separate storm drain |
| Apr 5, 2013 | 1K gal | Equipment Failure | — | Separate storm drain |
| Mar 28, 2013 | 720 gal | Other / Unknown | — | Separate storm drain |
| Jan 3, 2013 | 525 gal | Other / Unknown | — | Unpaved surface |
| Dec 25, 2012 | 5K gal | Equipment Failure | Yes | Surface water;Unpaved surface |
| Oct 27, 2012 | 410 gal | Equipment Failure | Yes | Separate storm drain |
| Oct 14, 2012 | 300 gal | Root Intrusion | — | Unpaved surface |
| Sep 30, 2012 | 4K gal | Equipment Failure | Yes | Separate storm drain;Street/curb and gutter |
| Jun 9, 2012 | 3K gal | Equipment Failure | Yes | Separate storm drain |
| Jun 4, 2012 | 1K gal | Equipment Failure | Yes | Separate storm drain |
| May 10, 2012 | 2K gal | Root Intrusion | Yes | Separate storm drain;Street/curb and gutter;Surface water |
| Mar 31, 2012 | 6K gal | Grease / FOG | Yes | Surface water |
| Mar 20, 2012 | 5K gal | Equipment Failure | Yes | Unpaved surface |
| Mar 5, 2012 | 600 gal | Equipment Failure | — | Unpaved surface |
| Jan 13, 2012 | 15 gal | Other / Unknown | — | Unpaved surface |
| Jan 9, 2012 | 2K gal | Other / Unknown | — | Unpaved surface |
| Dec 27, 2011 | 300 gal | Other / Unknown | — | Separate storm drain;Street/curb and gutter |
| Dec 13, 2011 | 30 gal | Equipment Failure | — | Street/curb and gutter |
| Oct 26, 2011 | 1K gal | Other / Unknown | Yes | Street/curb and gutter;Surface water |
| Sep 22, 2011 | 50 gal | Other / Unknown | Yes | Other (specify below) |
| Sep 2, 2011 | 60 gal | Equipment Failure | — | Unpaved surface |
| May 24, 2011 | 900 gal | Other / Unknown | — | Unpaved surface |
| May 6, 2011 | 2K gal | Other / Unknown | Yes | Surface water |
| Apr 25, 2011 | 100 gal | Equipment Failure | — | Street/curb and gutter;Unpaved surface |
| Mar 24, 2011 | 900 gal | Other / Unknown | Yes | Separate storm drain |
| Mar 24, 2011 | 1K gal | Other / Unknown | Yes | Separate storm drain |
| Mar 15, 2011 | 100 gal | Other / Unknown | — | Unpaved surface |
| Feb 11, 2011 | 100 gal | Equipment Failure | Yes | Separate storm drain;Surface water |
| Jan 3, 2011 | 200 gal | Other / Unknown | — | Separate storm drain |
| Oct 30, 2010 | 450 gal | Other / Unknown | Yes | Separate storm drain |
| Oct 26, 2010 | 2K gal | Other / Unknown | — | Storm drain |
| Aug 29, 2010 | 500 gal | Other / Unknown | — | Storm drain |
| Jun 26, 2010 | 25 gal | Other / Unknown | — | Other paved surface |
| May 6, 2010 | 900 gal | Other / Unknown | Yes | Separate storm drain;Surface water |
| May 2, 2010 | 1K gal | Other / Unknown | — | Unpaved surface |
| Apr 16, 2010 | 200 gal | Other / Unknown | — | Other (specify below) |
| Mar 5, 2010 | 100 gal | Equipment Failure | — | Street/curb and gutter |
| Feb 18, 2010 | 5 gal | Grease / FOG | — | Street/curb and gutter |
| Feb 8, 2010 | 900 gal | Equipment Failure | — | Separate storm drain |
| Jan 19, 2010 | 8K gal | Other / Unknown | — | Separate storm drain |
| Dec 13, 2009 | 400 gal | Other / Unknown | — | Separate storm drain |
| Dec 4, 2009 | 600 gal | Other / Unknown | Yes | Separate storm drain |
| Nov 29, 2009 | 70 gal | Other / Unknown | — | Unpaved surface |
| Nov 29, 2009 | 125 gal | Root Intrusion | — | Street/curb and gutter;Unpaved surface |
| Nov 18, 2009 | 400 gal | Root Intrusion | — | Unpaved surface |
| Nov 9, 2009 | 3K gal | Other / Unknown | Yes | Separate storm drain |
| Oct 18, 2009 | 2K gal | Root Intrusion | Yes | Separate storm drain |
| Oct 14, 2009 | 750 gal | Root Intrusion | — | Building or structure;Unpaved surface |
| Jun 2, 2009 | 200 gal | Root Intrusion | — | Street/curb and gutter |
| Jun 1, 2009 | 600 gal | Grease / FOG | — | Unpaved surface |
| May 31, 2009 | 5K gal | Equipment Failure | Yes | Surface water |
| Apr 27, 2009 | 500 gal | Root Intrusion | — | Unpaved surface |
| Feb 26, 2009 | 250 gal | Grease / FOG | — | Street/curb and gutter;Unpaved surface |
Source: California (CIWQS). Volumes are utility-reported estimates. Some events lack precise coordinates or volumes.