Steamboat Slough

River in California, past Isleton, Rio Vista, Snug Harbor and Walnut Grove

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.

Bookmark this water page and check it before each trip · Report a missing notice or error

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: Surface Water - Freshwater Harmful Algal Blooms (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 Steamboat Slough

Cyanobacteria (harmful blue-green algae) can make water unfit for contact; the issuing authority decides when its advisory ends.

Reports linked to Steamboat Slough, newest first
When	Report	Status
Jul 20 ’21to Dec 31 ’21	California State Water Resources Control Board (FHAB program) · Right side · Algae advisory · volume not reported report · notice · map	lifted

Sources: Surface Water - Freshwater Harmful Algal Blooms, retrieved 2026-11-06 03:07 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: 2021 (1 here)

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

Hogback Island, Isleton · Boat ramp
Sandy Beach Park and BLF, Rio Vista · Boat ramp

Source: OpenBoatLaunch launch records (public agency data and OpenStreetMap, Open Database License). · Steamboat Slough on OpenBoatLaunch

Nearby waters

Sherman Lake, CA No current status shown about 23 km away
New York Slough, CA No current status shown about 27 km away
Contra Loma Reservoir, CA No current status shown about 31 km away
Lodi Lake, CA No current status shown about 31 km away
Alamo Creek, CA No current status shown about 32 km away

Sources covering this water

Surface Water - Freshwater Harmful Algal Blooms · Latest check succeeded · Last successful check: 2026-11-06 08:37 UTC

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