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California · California (CIWQS)

Half Moon Bay City

C
Often reaches water
Reported events
82
Total volume
224K gal
Reached waterways
15 (18%)
Reporting since
2007

What caused the overflows

Grease / FOG
25
Other / Unknown
22
Equipment Failure
15
Root Intrusion
12
Capacity Issue
6
Rainfall / Flooding
2

Reported overflow events (showing 82 of 82)

DateVolumeCauseReached waterReceiving water
Mar 30, 2026235 galEquipment Failure——
Mar 30, 2026235 galEquipment Failure——
Sep 1, 202375 galOther / Unknown——
Jan 14, 2023521 galCapacity IssueYesDrainage Channel;Paved Surface;Street/Curb and Gutter;Unpaved surface
Jan 14, 20235K galCapacity Issue—Unpaved surface
Jan 4, 202315K galCapacity Issue—Unpaved surface
Jan 4, 20237 galOther / UnknownYesSeparate Storm Drain
Dec 31, 202288K galCapacity Issue—Unpaved surface
Dec 13, 202129K galOther / UnknownYesUnpaved surface
Nov 14, 2021208 galEquipment Failure—Other (specify below)
Aug 24, 202125 galRoot Intrusion—Paved Surface;Unpaved surface
Jul 27, 20203 galEquipment Failure—Unpaved surface
Aug 13, 20196 galOther / Unknown—Unpaved surface
Dec 1, 2017900 galOther / UnknownYesBeach
Nov 23, 2017180 galOther / Unknown—Unpaved surface
Oct 11, 20176K galGrease / FOGYesBeach
Mar 21, 2017300 galOther / UnknownYesBeach
Feb 20, 201720K galEquipment Failure—Unpaved surface
Jan 4, 20171K galCapacity IssueYesBeach
Sep 17, 201620 galRoot Intrusion—Building or Structure
Aug 9, 201615 galRoot Intrusion—Unpaved surface
Nov 12, 2015150 galRoot Intrusion—Drainage Channel;Separate Storm Drain
Aug 20, 201550 galGrease / FOG—Paved Surface;Unpaved surface
Aug 15, 20152K galEquipment Failure—Separate Storm Drain
Aug 14, 2015600 galOther / Unknown—Building or Structure
Jul 16, 20154K galGrease / FOG—Separate Storm Drain;Unpaved surface
Jul 16, 20154K galGrease / FOG—Unpaved surface
Dec 11, 20143K galRainfall / FloodingYesBeach;Separate Storm Drain;Street/Curb and Gutter
Sep 24, 2014330 galRoot Intrusion—Separate Storm Drain
Sep 11, 2014675 galRoot Intrusion—Unpaved surface
Aug 30, 20148K galEquipment Failure—Beach
Jul 27, 20141K galGrease / FOG—Building or Structure
Jun 23, 20146K galGrease / FOG—Beach
May 21, 2014500 galGrease / FOG—Beach
Mar 21, 20143 galEquipment Failure—Paved Surface
Mar 21, 2014449 galEquipment Failure—Paved Surface;Unpaved surface
Feb 17, 20142K galEquipment FailureYesOther (specify below)
Dec 23, 201210K galCapacity Issue—Other paved surface;Unpaved surface
Dec 2, 2012200 galRainfall / Flooding—Other (specify below)
Jun 19, 20123 galOther / Unknown—Other (specify below)
May 23, 2012750 galRoot IntrusionYesOther paved surface;Separate storm drain;Surface water;Unpaved surface
Feb 9, 20124 galOther / Unknown—Building or structure;Other (specify below)
Feb 4, 2012150 galOther / Unknown—Street/curb and gutter
Jan 16, 201225 galOther / Unknown—Building or structure
Dec 17, 2011625 galOther / Unknown—Separate storm drain
Dec 4, 2011500 galOther / UnknownYesBeach;Separate storm drain;Street/curb and gutter
Nov 13, 20113K galGrease / FOG—Unpaved surface
Oct 16, 201115 galGrease / FOG—Other paved surface
Oct 2, 201125 galGrease / FOG—Unpaved surface
Aug 20, 2011329 galOther / Unknown—Separate storm drain;Street/curb and gutter
May 22, 201125 galGrease / FOG—Other paved surface
May 3, 2011500 galGrease / FOG—Unpaved surface
May 2, 201120 galGrease / FOG—Unpaved surface
Jan 15, 20115 galGrease / FOG—Unpaved surface
Jan 5, 2011500 galRoot IntrusionYesBeach;Separate storm drain;Unpaved surface
Dec 29, 2010200 galGrease / FOG—Unpaved surface
Aug 20, 201010 galGrease / FOG—Street/curb and gutter
Aug 11, 20105 galGrease / FOG—Unpaved surface
Mar 23, 2010175 galOther / UnknownYesStorm drain
Feb 4, 20105 galOther / Unknown—Other paved surface
Jan 15, 201050 galEquipment Failure—Other paved surface;Unpaved surface
Dec 23, 200980 galOther / Unknown—Other paved surface
Dec 10, 200950 galOther / Unknown—Other paved surface
Nov 13, 20091 galOther / Unknown—Other paved surface
Nov 7, 2009100 galGrease / FOG—Unpaved surface
Oct 19, 20095 galEquipment Failure—Unpaved surface
Sep 19, 20095 galRoot Intrusion—Unpaved surface
Aug 8, 20095 galRoot Intrusion—Unpaved surface
Jul 30, 20094K galEquipment FailureYesBeach;Surface water
May 9, 200920 galEquipment Failure—Unpaved surface
Apr 8, 200925 galOther / Unknown—Unpaved surface
Dec 18, 20085 galEquipment Failure—Other paved surface;Unpaved surface
Oct 29, 2008800 galRoot Intrusion—Unpaved surface
Oct 9, 2008100 galRoot Intrusion—Other paved surface;Unpaved surface
May 22, 20085 galGrease / FOG—Unpaved surface
May 4, 20082K galGrease / FOG—Other paved surface;Unpaved surface
Apr 4, 200810 galGrease / FOG—Unpaved surface
Mar 23, 2008121 galOther / UnknownYesSeparate storm drain
Mar 23, 200810 galGrease / FOG—Unpaved surface;Other paved surface;Storm drain;Street/curb and gutter
Feb 23, 20082 galGrease / FOG—Unpaved surface
May 19, 200750 galGrease / FOG—Building or structure
May 19, 2007650 galGrease / FOG—Unpaved surface

Source: California (CIWQS). Volumes are utility-reported estimates. Some events lack precise coordinates or volumes.