Skip Navigation Link weather.gov  
NOAA logo - Click to go to the NOAA homepage National Weather Service NWS logo - Click to go to the NWS homepage
Advanced Hydrologic Prediction Service
Image background of Navigation bar Left
Bookmark and Share Navigation Bar End Cap

  
 

Web Portal Changes: In Spring 2024, the Advanced Hydrologic Prediction Service (AHPS) hosted at https://water.weather.gov will be replaced by the National Water Prediction Service (NWPS) at a repurposed https://water.noaa.gov. A preview of NWPS is available here, where you can see your station hydrograph by replacing SSSSS with the station 5-character id: https://preview.water.noaa.gov/gauges/SSSSS.

Flood Inundation Mapping: Experimental real-time flood Inundation mapping services for 10% of the United States are now available via the NWS Map Viewer. Additional products and geospatial services depicting River Forecast Center and National Water Model forecasts continue to be accessible as described in the StoryMap here.

Please visit https://www.weather.gov/owp/operations for more information.



Hydrograph River at a Glance Download
Willow Brook at Old Redwood Highway Bridge Stage (ft)Highest Observation: 32.87 ft at 1:10PM Feb 24, 2024Highest Observation: 32.87 ft at 2:08PM Feb 24, 2024Observed: 32.84 ft at 3:06PM Feb 24, 2024Observed: 32.84 ft at 4:05PM Feb 24, 2024Observed: 32.84 ft at 5:03PM Feb 24, 2024Observed: 32.82 ft at 6:01PM Feb 24, 2024Observed: 32.82 ft at 7:00PM Feb 24, 2024Observed: 32.79 ft at 7:58PM Feb 24, 2024Observed: 32.79 ft at 8:56PM Feb 24, 2024Observed: 32.79 ft at 9:55PM Feb 24, 2024Observed: 32.77 ft at 10:53PM Feb 24, 2024Observed: 32.74 ft at 11:51PM Feb 24, 2024Observed: 32.77 ft at 12:50AM Feb 25, 2024Observed: 32.74 ft at 1:48AM Feb 25, 2024Observed: 32.74 ft at 2:46AM Feb 25, 2024Observed: 32.74 ft at 3:45AM Feb 25, 2024Observed: 32.74 ft at 4:43AM Feb 25, 2024Observed: 32.74 ft at 5:41AM Feb 25, 2024Observed: 32.74 ft at 6:40AM Feb 25, 2024Observed: 32.74 ft at 7:38AM Feb 25, 2024Observed: 32.74 ft at 8:36AM Feb 25, 2024Observed: 32.74 ft at 9:35AM Feb 25, 2024Observed: 32.74 ft at 10:33AM Feb 25, 2024Observed: 32.72 ft at 11:31AM Feb 25, 2024Observed: 32.72 ft at 12:30PM Feb 25, 2024Observed: 32.72 ft at 1:28PM Feb 25, 2024Observed: 32.74 ft at 2:26PM Feb 25, 2024Observed: 32.69 ft at 3:25PM Feb 25, 2024Observed: 32.72 ft at 4:23PM Feb 25, 2024Observed: 32.69 ft at 5:21PM Feb 25, 2024Observed: 32.69 ft at 6:20PM Feb 25, 2024Observed: 32.69 ft at 7:18PM Feb 25, 2024Observed: 32.69 ft at 8:16PM Feb 25, 2024Observed: 32.67 ft at 9:15PM Feb 25, 2024Observed: 32.67 ft at 10:13PM Feb 25, 2024Observed: 32.67 ft at 11:11PM Feb 25, 2024Observed: 32.64 ft at 12:10AM Feb 26, 2024Observed: 32.64 ft at 1:08AM Feb 26, 2024Observed: 32.67 ft at 2:06AM Feb 26, 2024Observed: 32.64 ft at 3:05AM Feb 26, 2024Observed: 32.64 ft at 4:03AM Feb 26, 2024Observed: 32.64 ft at 5:01AM Feb 26, 2024Observed: 32.64 ft at 6:58AM Feb 26, 2024Observed: 32.64 ft at 7:56AM Feb 26, 2024Observed: 32.64 ft at 8:55AM Feb 26, 2024Observed: 32.64 ft at 9:53AM Feb 26, 2024Observed: 32.64 ft at 10:51AM Feb 26, 2024Observed: 32.64 ft at 11:50AM Feb 26, 2024Observed: 32.64 ft at 12:48PM Feb 26, 2024Observed: 32.64 ft at 1:46PM Feb 26, 2024Observed: 32.64 ft at 2:45PM Feb 26, 2024Observed: 32.64 ft at 3:43PM Feb 26, 2024Observed: 32.62 ft at 4:41PM Feb 26, 2024Observed: 32.62 ft at 5:40PM Feb 26, 2024Observed: 32.62 ft at 6:38PM Feb 26, 2024Observed: 32.59 ft at 7:36PM Feb 26, 2024Observed: 32.59 ft at 8:35PM Feb 26, 2024Observed: 32.59 ft at 9:33PM Feb 26, 2024Observed: 32.57 ft at 10:31PM Feb 26, 2024Observed: 32.59 ft at 1:26AM Feb 27, 2024Observed: 32.57 ft at 2:25AM Feb 27, 2024Observed: 32.57 ft at 3:23AM Feb 27, 2024Observed: 32.57 ft at 4:21AM Feb 27, 2024Observed: 32.57 ft at 5:20AM Feb 27, 2024Observed: 32.57 ft at 6:18AM Feb 27, 2024Observed: 32.54 ft at 7:16AM Feb 27, 2024Observed: 32.57 ft at 8:15AM Feb 27, 2024Observed: 32.57 ft at 9:13AM Feb 27, 2024Observed: 32.52 ft at 10:11AM Feb 27, 2024Observed: 32.59 ft at 11:10AM Feb 27, 2024Observed: 32.57 ft at 12:08PM Feb 27, 2024Observed: 32.57 ft at 1:06PM Feb 27, 2024Observed: 32.54 ft at 2:05PM Feb 27, 2024Observed: 32.54 ft at 3:03PM Feb 27, 2024Observed: 32.54 ft at 4:01PM Feb 27, 2024Observed: 32.54 ft at 5:58PM Feb 27, 2024Observed: 32.54 ft at 6:56PM Feb 27, 2024Observed: 32.54 ft at 7:55PM Feb 27, 2024Observed: 32.52 ft at 8:53PM Feb 27, 2024Observed: 32.52 ft at 9:51PM Feb 27, 2024Observed: 32.52 ft at 10:50PM Feb 27, 2024Observed: 32.49 ft at 11:48PM Feb 27, 2024Observed: 32.49 ft at 12:46AM Feb 28, 2024Observed: 32.49 ft at 1:45AM Feb 28, 2024Observed: 32.49 ft at 2:43AM Feb 28, 2024Observed: 32.49 ft at 3:41AM Feb 28, 2024Observed: 32.49 ft at 4:40AM Feb 28, 2024Observed: 32.49 ft at 5:38AM Feb 28, 2024Observed: 32.49 ft at 6:34AM Feb 28, 2024Observed: 32.49 ft at 7:35AM Feb 28, 2024Observed: 32.47 ft at 8:33AM Feb 28, 2024Observed: 32.49 ft at 9:31AM Feb 28, 2024Observed: 32.47 ft at 10:30AM Feb 28, 2024Observed: 32.52 ft at 11:28AM Feb 28, 2024Observed: 32.49 ft at 12:26PM Feb 28, 2024Observed: 32.49 ft at 2:23PM Feb 28, 2024Observed: 32.49 ft at 3:21PM Feb 28, 2024Observed: 32.47 ft at 4:20PM Feb 28, 2024Observed: 32.49 ft at 5:18PM Feb 28, 2024Observed: 32.47 ft at 6:16PM Feb 28, 2024Observed: 32.47 ft at 7:15PM Feb 28, 2024Observed: 32.47 ft at 8:13PM Feb 28, 2024Observed: 32.44 ft at 9:11PM Feb 28, 2024Observed: 32.47 ft at 10:10PM Feb 28, 2024Observed: 32.47 ft at 11:08PM Feb 28, 2024Observed: 32.44 ft at 12:06AM Feb 29, 2024Observed: 32.44 ft at 1:05AM Feb 29, 2024Observed: 32.44 ft at 2:03AM Feb 29, 2024Observed: 32.44 ft at 3:01AM Feb 29, 2024Observed: 32.47 ft at 4:00AM Feb 29, 2024Observed: 32.44 ft at 4:58AM Feb 29, 2024Observed: 32.44 ft at 5:56AM Feb 29, 2024Observed: 32.44 ft at 6:55AM Feb 29, 2024Observed: 32.44 ft at 7:53AM Feb 29, 2024Observed: 32.44 ft at 8:51AM Feb 29, 2024PTMC1(plotting HGIRR) Graph Created (1:00PM Feb 29, 2024)ObservedLatest observed value: 32.44 ft at 8:51 AM PST 29-Feb-2024. Flood Stage is 40.7 ft
Printable Image
About this graph
Tabular Data (UTC)
Tabular Data (PST)
XML Data
RSS Files
Datum: Not Available
Metadata
NOTE: Graphical forecasts are not available for the Willow Brook at Old Redwood Highway Bridge. During times of high water, forecast crest information can be found in the text products.
Return to Area Map
Flood Categories (in feet)
Major Flood Stage: 44.3
Moderate Flood Stage: 43
Flood Stage: 40.7
Action Stage: 40.7
Low Stage (in feet): -9999

Historic Crests
Currently none available.

Recent Crests
Currently none available.

Low Water Records
Currently none available.
Zoom Level:14
KML Image
Gauge LocationGauge Map Marker
Disclaimer
Latitude/Longitude Disclaimer: The gauge location shown in the above map is the approximate location based on the latitude/longitude coordinates provided to the NWS by the gauge owner.
Flood Impacts & Photos Collapse
If you notice any errors in the below information, please contact our Webmaster
44.3 Major Flood Stage. Water level has reached by bottom of the bridge soffit.
43.9 Flood waters flowing down Redwood Way at Old Redwood Highway.
43.2 Water levels are above bankfull and begin flowing through upstream businesses, including passing through the old lumber company's parking lot.
43 Moderate Flood Stage. A local detention basin may begin to release water onto North McDowell Blvd. Ext.
42.3 Water begins to flow across Ely Road at the railroad track near Old Redwood Highway. Holm Road begins to flood and water ponds on North McDowell at the Post Office.
41.7 City of Petaluma will notify the City Manager and evaluate the need to activate the Emergency Operations Center.
40.7 Action Stage. NWS and City of Petaluma will be closely monitoring the situation. NWS will issue an urban/small stream advisory if not already issued.
About This Location Collapse

Latitude: 38.279722° N, Longitude: 122.669444° W, Horizontal Datum: NAD83/WGS84

River Stage
Reference Frame
Gauge Height Flood Stage Uses
NWS stage 0 ft 40.7 ft Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps
Vertical Datum Elevation
(gauge height = 0)
Elevation
(gauge height = flood stage)
Elevation information source
NAVD88 Not Available Not Available Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps
NGVD 29 Not Available Not Available Older USGS topographic maps, NGVD29 benchmarks
MSL Not Available Not Available Older USGS topographic maps, MSL benchmarks
Other Not Available Not Available  
Resources Collapse
Hydrologic Resources Additional Resources
Collaborative Agencies Collapse
The National Weather Service prepares its forecasts and other services in collaboration with agencies like the US Geological Survey, US Bureau of Reclamation, US Army Corps of Engineers, Natural Resource Conservation Service, National Park Service, ALERT Users Group, Bureau of Indian Affairs, and many state and local emergency managers across the country. For details, please click here.
NWS Information
National Weather Service
San Francisco Bay Area Weather Forecast Office
21 Grace Hopper Ave, Stop 5
Monterey, CA 93943-5505
(831) 656-1725
Ask Questions/Webmaster
Page last modified: 2-Nov-2020 7:27 PM
Disclaimer
Credits
Glossary
Privacy Policy
About Us
Career Opportunities