Foster City Lagoon

Bay in California, near Foster City

No current status shown

No current status is assigned to this water outline. Check the water page for reports and any estimated downstream stretches. Why this status, and its source

Map sources: water outlines and launches from OpenBoatLaunch and OpenStreetMap contributors (Open Database License); wastewater outlets from EPA and state records; downstream estimates by DirtyWaterWatch using U.S. Geological Survey maps and flow data. Base map: OpenFreeMap and OpenMapTiles.

Square boat markers mark boat launches listed by OpenBoatLaunch.

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About this status

No current status shown: no report we track sets a status on this water now; how statuses work. No status does not mean the water is safe. Follow posted signs and local health advice.

Sources checked: Beach Watch: Beach Advisories (Postings and Closures) and Beach Water Quality Monitoring (last successful check 2026-11-06 08:37 UTC). Status by DirtyWaterWatch, updated 2026-11-06 09:03 UTC. · Updated Nov 6, 2026, 1:03 AM PST

The last 90 days

Last 90 days, hour by hour. Red: discharge or advisory reported. Amber: caution. Hatched amber: end not confirmed. Plum: algal bloom advisory. Red or amber with a light line inside: beach advisory or caution. Dotted: monthly report (days with discharge, dates not given). Grey: no current status on the water outline. Purple hatching: a status resting on a source that could not be checked on schedule.

No discharge, advisory or caution periods are shown for this water in this time span. Check downstream stretches and source coverage.

Source: DirtyWaterWatch calculations using the reports named above and the published status rules. Updated 2026-11-06 09:03 UTC.

Reported discharges over time

Historical charts are not available here. See the reports and sources on this page.

Reports linked to Foster City Lagoon

Reports linked to Foster City Lagoon, newest first
When	Report	Status
Feb 11, 10:00 AM PSTto Feb 25, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Erckenbrack Park, Foster City - Erckenbrack Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Jan 1, 10:00 AM PSTto Feb 4, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Erckenbrack Park, Foster City - Erckenbrack Park, at beach · Beach advisory · volume in each report map	lifted
Jan 1, 10:00 AM PSTto Feb 4, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Erckenbrack Park, Foster City - Erckenbrack Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Jan 1, 10:00 AM PSTto Feb 25, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Marlin Park, Foster City - Marlin Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Jan 1, 10:00 AM PSTto Feb 4, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Gull Park, Foster City - Gull Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Oct 16 ’25, 10:00 AM PDTto Dec 31 ’25, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Marlin Park, Foster City - Marlin Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Jul 16 ’25, 10:00 AM PDTto Sep 24 ’25, 10:00 AM PDT	Health Department County of San Mateo Environmental Health via Beach Watch · Marlin Park, Foster City - Marlin Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Jul 2 ’25, 10:00 AM PDTto Dec 31 ’25, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Gull Park, Foster City - Gull Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
May 29 ’25, 10:00 AM PDTto Dec 31 ’25, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Erckenbrack Park, Foster City - Erckenbrack Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
May 14 ’25, 10:00 AM PDTto Jun 18 ’25, 10:00 AM PDT	Health Department County of San Mateo Environmental Health via Beach Watch · Gull Park, Foster City - Gull Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Mar 19 ’25, 10:00 AM PDTto Jul 2 ’25, 10:00 AM PDT	Health Department County of San Mateo Environmental Health via Beach Watch · Marlin Park, Foster City - Marlin Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Mar 12 ’25, 10:00 AM PDTto Apr 30 ’25, 10:00 AM PDT	Health Department County of San Mateo Environmental Health via Beach Watch · Gull Park, Foster City - Gull Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Jan 1 ’25, 12:00 AM PSTto May 14 ’25, 10:00 AM PDT	Health Department County of San Mateo Environmental Health via Beach Watch · Erckenbrack Park, Foster City - Erckenbrack Park, at beach · Beach advisory · volume in each report map	lifted
Jan 1 ’25, 12:00 AM PSTto May 14 ’25, 10:00 AM PDT	Health Department County of San Mateo Environmental Health via Beach Watch · Erckenbrack Park, Foster City - Erckenbrack Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Jan 1 ’25, 12:00 AM PSTto Feb 12 ’25, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Gull Park, Foster City - Gull Park, at beach · Beach advisory · volume not reported report · notice · map	lifted
Jan 1 ’25, 12:00 AM PSTto Feb 12 ’25, 10:00 AM PST	Health Department County of San Mateo Environmental Health via Beach Watch · Marlin Park, Foster City - Marlin Park, at beach · Beach advisory · volume not reported report · notice · map	lifted

Sources: Beach Watch: Beach Advisories (Postings and Closures) and Beach Water Quality Monitoring, retrieved 2026-11-04 15:26 UTC. A report's record id and times show when you hover or focus its "report" link.

Download these reports as CSV

All reports in California by year: 2026 (4 here) · 2025 (10 here)

Beaches named in these records: Erckenbrack Park, Foster City - Erckenbrack Park, at beach, Gull Park, Foster City - Gull Park, at beach, Marlin Park, Foster City - Marlin Park, at beach.

Wastewater outlets on this water

Outfall: a pipe or outlet where wastewater enters a water body.

No wastewater outlet in our records is linked to this water.

Boat launches

Boat Park (Foster City) · Boat ramp
Leo J Ryan Memorial Park (Foster City) · Boat ramp

Source: OpenBoatLaunch launch records (public agency data and OpenStreetMap, Open Database License). · Foster City Lagoon on OpenBoatLaunch

Nearby waters

Seal Slough, CA No current status shown about 2 km away
Laurel Creek, CA No current status shown about 4 km away
San Mateo Creek, CA No current status shown about 10 km away
Redwood Creek, CA No current status shown about 10 km away
Unnamed stream near Millbrae, CA No current status shown about 11 km away

Sources covering this water

Beach Watch: Beach Advisories (Postings and Closures) and Beach Water Quality Monitoring · Latest check succeeded · Last successful check: 2026-11-06 08:37 UTC

14 records linked to this water. Updated Nov 6, 2026, 1:03 AM PST.