All rankings
California · California (CIWQS)
Mill Valley City
B
Seldom reaches water
Reported events
443
Total volume
86K gal
Reached waterways
37 (8%)
Reporting since
2007
What caused the overflows
Root Intrusion
269
Other / Unknown
92
Equipment Failure
42
Grease / FOG
40
Reported overflow events (showing 200 of 443)
| Date | Volume | Cause | Reached water | Receiving water |
|---|---|---|---|---|
| Jan 21, 2026 | 780 gal | Grease / FOG | — | — |
| Jan 19, 2026 | 758 gal | Root Intrusion | — | — |
| Sep 2, 2025 | 153 gal | Root Intrusion | Yes | Arroyo Corte Madera de Presidio |
| Jun 4, 2025 | 233 gal | Root Intrusion | — | — |
| Mar 13, 2025 | 399 gal | Root Intrusion | — | — |
| Oct 29, 2024 | 105 gal | Root Intrusion | — | — |
| Oct 26, 2024 | 525 gal | Root Intrusion | — | — |
| Oct 18, 2024 | 188 gal | Root Intrusion | — | — |
| Oct 12, 2024 | 2K gal | Grease / FOG | Yes | Arroyo Corte Madera del Presidio |
| Jun 21, 2024 | 240 gal | Equipment Failure | — | — |
| May 24, 2024 | 50 gal | Root Intrusion | — | — |
| Jan 9, 2024 | 60 gal | Grease / FOG | — | — |
| Dec 10, 2023 | 100 gal | Equipment Failure | Yes | Old Mill Creek |
| Nov 27, 2023 | 216 gal | Root Intrusion | Yes | Arroyo Corte Madera del Presidio |
| Oct 12, 2023 | 50 gal | Root Intrusion | — | — |
| Sep 8, 2023 | 67 gal | Equipment Failure | — | — |
| Apr 13, 2023 | 15 gal | Grease / FOG | — | Unpaved surface |
| Jun 23, 2022 | 2 gal | Root Intrusion | — | Paved Surface |
| Jun 23, 2022 | 10 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter |
| Apr 19, 2022 | 45 gal | Root Intrusion | — | Unpaved surface |
| Mar 23, 2022 | 84 gal | Other / Unknown | — | Unpaved surface |
| Dec 21, 2021 | 5 gal | Root Intrusion | — | Paved Surface |
| Dec 8, 2021 | 15 gal | Root Intrusion | — | Paved Surface |
| Oct 17, 2021 | 400 gal | Root Intrusion | Yes | Street/Curb and Gutter |
| Aug 9, 2021 | 306 gal | Grease / FOG | — | Paved Surface |
| Aug 3, 2021 | 15 gal | Equipment Failure | — | Paved Surface |
| Jul 4, 2021 | 20 gal | Root Intrusion | — | Street/Curb and Gutter;Unpaved surface |
| May 19, 2021 | 35 gal | Other / Unknown | — | Unpaved surface |
| Apr 26, 2021 | 10 gal | Equipment Failure | — | Unpaved surface |
| Apr 3, 2021 | 120 gal | Other / Unknown | Yes | Street/Curb and Gutter;Surface Water |
| Mar 4, 2021 | 10 gal | Root Intrusion | — | Paved Surface |
| Jan 10, 2021 | 3 gal | Other / Unknown | — | Unpaved surface |
| Dec 19, 2020 | 8 gal | Root Intrusion | — | Street/Curb and Gutter |
| Dec 7, 2020 | 8 gal | Other / Unknown | — | Paved Surface;Street/Curb and Gutter |
| Nov 12, 2020 | 53 gal | Equipment Failure | — | Paved Surface |
| Oct 21, 2020 | 186 gal | Root Intrusion | — | Street/Curb and Gutter |
| Oct 13, 2020 | 43 gal | Other / Unknown | — | Street/Curb and Gutter |
| Sep 18, 2020 | 63 gal | Grease / FOG | — | Street/Curb and Gutter |
| Jul 31, 2020 | 6 gal | Equipment Failure | — | Paved Surface |
| Jun 10, 2020 | 800 gal | Root Intrusion | — | Street/Curb and Gutter |
| Mar 29, 2020 | 2K gal | Equipment Failure | Yes | Surface Water;Unpaved surface |
| Mar 23, 2020 | 4 gal | Root Intrusion | — | Paved Surface |
| Mar 19, 2020 | 234 gal | Root Intrusion | — | Paved Surface;Street/Curb and Gutter;Unpaved surface |
| Feb 29, 2020 | 7 gal | Grease / FOG | — | Separate Storm Drain;Street/Curb and Gutter;Unpaved surface |
| Nov 24, 2019 | 40 gal | Root Intrusion | — | Other (specify below) |
| Nov 15, 2019 | 50 gal | Root Intrusion | — | Unpaved surface |
| Nov 15, 2019 | 225 gal | Root Intrusion | — | Unpaved surface |
| Nov 7, 2019 | 200 gal | Equipment Failure | Yes | Surface Water;Unpaved surface |
| Oct 5, 2019 | 30 gal | Root Intrusion | — | Drainage Channel |
| Sep 30, 2019 | 161 gal | Equipment Failure | — | Unpaved surface |
| Aug 15, 2019 | 30 gal | Root Intrusion | — | Unpaved surface |
| Aug 2, 2019 | 100 gal | Root Intrusion | — | Other (specify below) |
| May 24, 2019 | 733 gal | Other / Unknown | Yes | Surface Water |
| May 2, 2019 | 65 gal | Equipment Failure | Yes | Drainage Channel |
| Apr 18, 2019 | 15 gal | Equipment Failure | — | Unpaved surface |
| Mar 28, 2019 | 10 gal | Root Intrusion | — | Other (specify below) |
| Feb 13, 2019 | 150 gal | Root Intrusion | Yes | Surface Water |
| Jan 25, 2019 | 470 gal | Equipment Failure | Yes | Surface Water;Unpaved surface |
| Jan 17, 2019 | 500 gal | Grease / FOG | — | Other (specify below) |
| Jan 4, 2019 | 25 gal | Grease / FOG | Yes | Other (specify below) |
| Dec 9, 2018 | 30 gal | Equipment Failure | — | Other (specify below) |
| Nov 27, 2018 | 20 gal | Root Intrusion | — | Other (specify below) |
| Nov 25, 2018 | 210 gal | Root Intrusion | — | Unpaved surface |
| Nov 13, 2018 | 100 gal | Root Intrusion | Yes | Other (specify below) |
| Nov 12, 2018 | 875 gal | Equipment Failure | — | Unpaved surface |
| Nov 5, 2018 | 210 gal | Root Intrusion | — | Other (specify below) |
| Oct 31, 2018 | 35 gal | Root Intrusion | — | Building or Structure |
| Oct 29, 2018 | 25 gal | Grease / FOG | — | Other (specify below) |
| Oct 17, 2018 | 10 gal | Root Intrusion | — | Unpaved surface |
| Oct 13, 2018 | 500 gal | Other / Unknown | — | Other (specify below);Street/Curb and Gutter |
| Sep 23, 2018 | 15 gal | Root Intrusion | — | Unpaved surface |
| Jul 31, 2018 | 600 gal | Grease / FOG | Yes | Drainage Channel;Unpaved surface |
| Jul 22, 2018 | 60 gal | Root Intrusion | Yes | Drainage Channel |
| Jul 10, 2018 | 5 gal | Root Intrusion | — | Unpaved surface |
| Jun 27, 2018 | 20 gal | Root Intrusion | — | Unpaved surface |
| Jun 10, 2018 | 100 gal | Equipment Failure | — | Street/Curb and Gutter;Unpaved surface |
| May 22, 2018 | 85 gal | Root Intrusion | — | Unpaved surface |
| Apr 6, 2018 | 50 gal | Root Intrusion | — | Unpaved surface |
| Feb 8, 2018 | 200 gal | Other / Unknown | — | Unpaved surface |
| Dec 24, 2017 | 200 gal | Root Intrusion | — | Drainage Channel;Unpaved surface |
| Dec 7, 2017 | 1K gal | Root Intrusion | — | Unpaved surface |
| Nov 30, 2017 | 25 gal | Root Intrusion | — | Other (specify below);Street/Curb and Gutter |
| Nov 24, 2017 | 105 gal | Equipment Failure | Yes | Drainage Channel;Paved Surface;Separate Storm Drain;Street/Curb and Gutter;Surface Water;Unpaved surface |
| Nov 7, 2017 | 50 gal | Root Intrusion | — | Other (specify below);Paved Surface |
| Oct 28, 2017 | 105 gal | Root Intrusion | Yes | Separate Storm Drain;Street/Curb and Gutter |
| Oct 20, 2017 | 135 gal | Equipment Failure | — | Street/Curb and Gutter |
| Oct 11, 2017 | 75 gal | Root Intrusion | — | Other (specify below) |
| Aug 19, 2017 | 150 gal | Root Intrusion | — | Separate Storm Drain;Street/Curb and Gutter |
| Jul 27, 2017 | 375 gal | Root Intrusion | Yes | Drainage Channel |
| Jul 21, 2017 | 100 gal | Other / Unknown | Yes | Separate Storm Drain |
| Jul 19, 2017 | 360 gal | Root Intrusion | — | Other (specify below) |
| Jun 28, 2017 | 5 gal | Root Intrusion | — | Unpaved surface |
| Apr 18, 2017 | 200 gal | Grease / FOG | — | Unpaved surface |
| Mar 28, 2017 | 50 gal | Other / Unknown | — | Unpaved surface |
| Jan 9, 2017 | 25 gal | Root Intrusion | — | Unpaved surface |
| Jan 5, 2017 | 10 gal | Root Intrusion | — | Unpaved surface |
| Jan 3, 2017 | 50 gal | Other / Unknown | — | Unpaved surface |
| Dec 15, 2016 | 50 gal | Root Intrusion | — | Street/Curb and Gutter |
| Dec 13, 2016 | 400 gal | Root Intrusion | — | Unpaved surface |
| Dec 6, 2016 | 75 gal | Root Intrusion | — | Street/Curb and Gutter |
| Dec 1, 2016 | 500 gal | Other / Unknown | — | Unpaved surface |
| Oct 24, 2016 | 25 gal | Equipment Failure | — | Street/Curb and Gutter |
| Oct 17, 2016 | 2 gal | Equipment Failure | — | Unpaved surface |
| Oct 9, 2016 | 300 gal | Root Intrusion | — | Other (specify below);Street/Curb and Gutter |
| Oct 5, 2016 | 500 gal | Equipment Failure | Yes | Separate Storm Drain |
| Sep 26, 2016 | 25 gal | Root Intrusion | — | Street/Curb and Gutter |
| Sep 26, 2016 | 50 gal | Other / Unknown | — | Other (specify below) |
| Sep 24, 2016 | 363 gal | Grease / FOG | — | Street/Curb and Gutter |
| Sep 19, 2016 | 50 gal | Root Intrusion | — | Unpaved surface |
| Aug 22, 2016 | 600 gal | Equipment Failure | Yes | Drainage Channel |
| Aug 19, 2016 | 50 gal | Root Intrusion | — | Unpaved surface |
| Aug 7, 2016 | 250 gal | Grease / FOG | Yes | Drainage Channel |
| Jul 31, 2016 | 500 gal | Root Intrusion | — | Street/Curb and Gutter;Unpaved surface |
| Jul 20, 2016 | 120 gal | Equipment Failure | — | Unpaved surface |
| Jul 17, 2016 | 120 gal | Equipment Failure | — | Unpaved surface |
| Jun 4, 2016 | 450 gal | Root Intrusion | — | Other (specify below) |
| Feb 25, 2016 | 50 gal | Other / Unknown | — | Street/Curb and Gutter |
| Feb 5, 2016 | 180 gal | Root Intrusion | — | Other (specify below) |
| Jan 28, 2016 | 15 gal | Other / Unknown | — | Street/Curb and Gutter |
| Jan 24, 2016 | 100 gal | Other / Unknown | — | Other (specify below) |
| Jan 8, 2016 | 60 gal | Root Intrusion | — | Other (specify below) |
| Jan 7, 2016 | 605 gal | Root Intrusion | — | Unpaved surface |
| Jan 3, 2016 | 50 gal | Root Intrusion | — | Other (specify below) |
| Jan 2, 2016 | 185 gal | Root Intrusion | — | Building or Structure |
| Dec 21, 2015 | 80 gal | Other / Unknown | — | Other (specify below) |
| Dec 16, 2015 | 15 gal | Root Intrusion | — | Unpaved surface |
| Dec 15, 2015 | 15 gal | Root Intrusion | — | Unpaved surface |
| Dec 13, 2015 | 100 gal | Other / Unknown | — | Other (specify below) |
| Dec 10, 2015 | 5 gal | Other / Unknown | — | Other (specify below) |
| Nov 16, 2015 | 60 gal | Root Intrusion | — | Unpaved surface |
| Nov 16, 2015 | 60 gal | Root Intrusion | — | Unpaved surface |
| Nov 4, 2015 | 800 gal | Other / Unknown | — | Other (specify below) |
| Oct 30, 2015 | 50 gal | Other / Unknown | — | Street/Curb and Gutter |
| Oct 28, 2015 | 5 gal | Equipment Failure | — | Unpaved surface |
| Oct 26, 2015 | 20 gal | Root Intrusion | — | Unpaved surface |
| Oct 21, 2015 | 30 gal | Root Intrusion | — | Other (specify below) |
| Oct 20, 2015 | 20 gal | Root Intrusion | — | Street/Curb and Gutter |
| Oct 19, 2015 | 250 gal | Root Intrusion | — | Street/Curb and Gutter |
| Oct 19, 2015 | 50 gal | Root Intrusion | — | Unpaved surface |
| Oct 13, 2015 | 25 gal | Grease / FOG | — | Unpaved surface |
| Sep 22, 2015 | 10 gal | Grease / FOG | — | Street/Curb and Gutter |
| Jul 24, 2015 | 135 gal | Root Intrusion | — | Other (specify below);Street/Curb and Gutter |
| Jul 13, 2015 | 5K gal | Other / Unknown | — | Unpaved surface |
| Jun 8, 2015 | 20 gal | Root Intrusion | — | Unpaved surface |
| May 26, 2015 | 5 gal | Other / Unknown | — | Paved Surface |
| May 7, 2015 | 5 gal | Root Intrusion | — | Paved Surface |
| May 4, 2015 | 100 gal | Equipment Failure | — | Unpaved surface |
| May 4, 2015 | 450 gal | Other / Unknown | — | Unpaved surface |
| Apr 13, 2015 | 25 gal | Equipment Failure | — | Street/Curb and Gutter |
| Apr 12, 2015 | 100 gal | Grease / FOG | — | Street/Curb and Gutter |
| Mar 17, 2015 | 40 gal | Equipment Failure | — | Street/Curb and Gutter |
| Mar 15, 2015 | 100 gal | Root Intrusion | — | Unpaved surface |
| Feb 26, 2015 | 50 gal | Other / Unknown | — | Unpaved surface |
| Feb 22, 2015 | 375 gal | Root Intrusion | — | Street/Curb and Gutter;Unpaved surface |
| Feb 14, 2015 | 300 gal | Root Intrusion | — | Other (specify below) |
| Feb 10, 2015 | 120 gal | Root Intrusion | — | Unpaved surface |
| Feb 9, 2015 | 5 gal | Equipment Failure | — | Paved Surface |
| Jan 30, 2015 | 40 gal | Other / Unknown | — | Separate Storm Drain |
| Jan 27, 2015 | 300 gal | Root Intrusion | — | Street/Curb and Gutter |
| Jan 24, 2015 | 375 gal | Other / Unknown | — | Unpaved surface |
| Jan 10, 2015 | 200 gal | Other / Unknown | — | Unpaved surface |
| Jan 6, 2015 | 20 gal | Root Intrusion | — | Separate Storm Drain |
| Dec 25, 2014 | 488 gal | Other / Unknown | — | Separate Storm Drain |
| Dec 15, 2014 | 18 gal | Root Intrusion | — | Street/Curb and Gutter |
| Dec 8, 2014 | 400 gal | Grease / FOG | Yes | Surface Water |
| Dec 7, 2014 | 100 gal | Other / Unknown | — | Other (specify below) |
| Nov 26, 2014 | 20 gal | Root Intrusion | — | Unpaved surface |
| Oct 23, 2014 | 100 gal | Root Intrusion | — | Unpaved surface |
| Oct 19, 2014 | 50 gal | Root Intrusion | — | Other (specify below) |
| Oct 16, 2014 | 50 gal | Root Intrusion | — | Paved Surface |
| Sep 24, 2014 | 60 gal | Grease / FOG | — | Street/Curb and Gutter |
| Sep 11, 2014 | 20 gal | Root Intrusion | — | Separate Storm Drain |
| Aug 23, 2014 | 450 gal | Root Intrusion | — | Other (specify below);Street/Curb and Gutter;Unpaved surface |
| Aug 16, 2014 | 50 gal | Root Intrusion | — | Street/Curb and Gutter |
| Aug 6, 2014 | 5 gal | Root Intrusion | — | Unpaved surface |
| Aug 4, 2014 | 22 gal | Root Intrusion | — | Paved Surface |
| Aug 4, 2014 | 22 gal | Root Intrusion | — | Street/Curb and Gutter |
| Jul 16, 2014 | 96 gal | Other / Unknown | — | Paved Surface |
| Jul 7, 2014 | 100 gal | Other / Unknown | — | Paved Surface |
| Jun 23, 2014 | 25 gal | Grease / FOG | — | Unpaved surface |
| Jun 14, 2014 | 90 gal | Root Intrusion | — | Unpaved surface |
| May 8, 2014 | 20 gal | Other / Unknown | — | Separate Storm Drain |
| May 2, 2014 | 30 gal | Root Intrusion | — | Separate Storm Drain |
| May 2, 2014 | 30 gal | Equipment Failure | Yes | Separate Storm Drain |
| Mar 13, 2014 | 50 gal | Other / Unknown | — | Paved Surface |
| Feb 10, 2014 | 300 gal | Equipment Failure | — | Separate Storm Drain |
| Feb 2, 2014 | 75 gal | Equipment Failure | — | Unpaved surface |
| Jan 20, 2014 | 2K gal | Equipment Failure | Yes | Surface Water |
| Dec 27, 2013 | 50 gal | Other / Unknown | — | Unpaved surface |
| Dec 3, 2013 | 85 gal | Equipment Failure | Yes | Surface Water |
| Nov 3, 2013 | 400 gal | Root Intrusion | Yes | Unpaved surface |
| Oct 28, 2013 | 5 gal | Root Intrusion | — | Paved Surface |
| Sep 2, 2013 | 375 gal | Root Intrusion | Yes | Separate storm drain;Surface water |
| Aug 31, 2013 | 75 gal | Other / Unknown | — | Street/Curb and Gutter;Separate storm drain |
| Aug 28, 2013 | 16 gal | Root Intrusion | — | Other (specify below) |
| Aug 13, 2013 | 21 gal | Root Intrusion | — | Street/curb and gutter |
| Aug 12, 2013 | 20 gal | Root Intrusion | — | Unpaved surface |
| Jul 15, 2013 | 20 gal | Other / Unknown | — | Street/curb and gutter |
| Jul 7, 2013 | 39 gal | Root Intrusion | — | Street/Curb and Gutter |
| May 30, 2013 | 25 gal | Root Intrusion | — | Unpaved surface |
Source: California (CIWQS). Volumes are utility-reported estimates. Some events lack precise coordinates or volumes.