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Hydrograph River at a Glance Download
Willow Brook at Old Redwood Highway Bridge Stage (ft)Observed: 32.62 ft at 10:03AM Mar 23, 2024Observed: 32.59 ft at 12:58PM Mar 23, 2024Observed: 32.59 ft at 1:56PM Mar 23, 2024Observed: 32.62 ft at 3:53PM Mar 23, 2024Observed: 32.64 ft at 4:51PM Mar 23, 2024Observed: 32.64 ft at 5:50PM Mar 23, 2024Observed: 32.64 ft at 6:48PM Mar 23, 2024Observed: 32.59 ft at 7:46PM Mar 23, 2024Observed: 32.59 ft at 8:45PM Mar 23, 2024Observed: 32.59 ft at 9:43PM Mar 23, 2024Observed: 32.62 ft at 10:41PM Mar 23, 2024Observed: 32.64 ft at 11:40PM Mar 23, 2024Observed: 32.64 ft at 12:38AM Mar 24, 2024Observed: 32.64 ft at 1:36AM Mar 24, 2024Observed: 32.62 ft at 2:35AM Mar 24, 2024Observed: 32.62 ft at 3:33AM Mar 24, 2024Observed: 32.62 ft at 4:31AM Mar 24, 2024Observed: 32.62 ft at 6:28AM Mar 24, 2024Observed: 32.64 ft at 7:26AM Mar 24, 2024Observed: 32.62 ft at 8:25AM Mar 24, 2024Observed: 32.62 ft at 9:23AM Mar 24, 2024Observed: 32.62 ft at 10:21AM Mar 24, 2024Observed: 32.59 ft at 11:20AM Mar 24, 2024Observed: 32.54 ft at 12:18PM Mar 24, 2024Observed: 32.54 ft at 1:16PM Mar 24, 2024Observed: 32.54 ft at 2:15PM Mar 24, 2024Observed: 32.54 ft at 3:13PM Mar 24, 2024Observed: 32.54 ft at 4:11PM Mar 24, 2024Observed: 32.52 ft at 5:10PM Mar 24, 2024Observed: 32.49 ft at 7:06PM Mar 24, 2024Observed: 32.49 ft at 8:05PM Mar 24, 2024Observed: 32.47 ft at 9:03PM Mar 24, 2024Observed: 32.44 ft at 10:01PM Mar 24, 2024Observed: 32.44 ft at 11:00PM Mar 24, 2024Observed: 32.47 ft at 11:58PM Mar 24, 2024Observed: 32.44 ft at 12:56AM Mar 25, 2024Observed: 32.44 ft at 1:55AM Mar 25, 2024Observed: 32.42 ft at 2:53AM Mar 25, 2024Observed: 32.42 ft at 3:51AM Mar 25, 2024Observed: 32.42 ft at 4:50AM Mar 25, 2024Observed: 32.39 ft at 5:48AM Mar 25, 2024Observed: 32.39 ft at 6:46AM Mar 25, 2024Observed: 32.39 ft at 7:45AM Mar 25, 2024Observed: 32.39 ft at 8:43AM Mar 25, 2024Observed: 32.39 ft at 9:42AM Mar 25, 2024Observed: 32.39 ft at 10:40AM Mar 25, 2024Observed: 32.39 ft at 11:38AM Mar 25, 2024Observed: 32.37 ft at 12:36PM Mar 25, 2024Observed: 32.37 ft at 2:33PM Mar 25, 2024Observed: 32.37 ft at 3:31PM Mar 25, 2024Observed: 32.37 ft at 4:30PM Mar 25, 2024Observed: 32.37 ft at 5:28PM Mar 25, 2024Observed: 32.34 ft at 6:26PM Mar 25, 2024Observed: 32.34 ft at 7:25PM Mar 25, 2024Observed: 32.34 ft at 8:23PM Mar 25, 2024Observed: 32.34 ft at 9:21PM Mar 25, 2024Observed: 32.34 ft at 10:20PM Mar 25, 2024Observed: 32.34 ft at 11:18PM Mar 25, 2024Observed: 32.34 ft at 12:16AM Mar 26, 2024Observed: 32.34 ft at 1:15AM Mar 26, 2024Observed: 32.34 ft at 2:13AM Mar 26, 2024Observed: 32.34 ft at 3:11AM Mar 26, 2024Observed: 32.34 ft at 4:10AM Mar 26, 2024Observed: 32.34 ft at 5:08AM Mar 26, 2024Observed: 32.32 ft at 6:06AM Mar 26, 2024Observed: 32.34 ft at 7:05AM Mar 26, 2024Observed: 32.34 ft at 8:03AM Mar 26, 2024Observed: 32.32 ft at 9:01AM Mar 26, 2024Observed: 32.32 ft at 10:00AM Mar 26, 2024Observed: 32.29 ft at 10:58AM Mar 26, 2024Observed: 32.32 ft at 11:56AM Mar 26, 2024Observed: 32.34 ft at 1:53PM Mar 26, 2024Observed: 32.32 ft at 2:51PM Mar 26, 2024Observed: 32.32 ft at 3:50PM Mar 26, 2024Observed: 32.29 ft at 4:48PM Mar 26, 2024Observed: 32.29 ft at 5:46PM Mar 26, 2024Observed: 32.29 ft at 6:45PM Mar 26, 2024Observed: 32.29 ft at 7:43PM Mar 26, 2024Observed: 32.29 ft at 8:41PM Mar 26, 2024Observed: 32.27 ft at 9:40PM Mar 26, 2024Observed: 32.29 ft at 10:38PM Mar 26, 2024Observed: 32.27 ft at 11:36PM Mar 26, 2024Observed: 32.29 ft at 12:35AM Mar 27, 2024Observed: 32.29 ft at 1:33AM Mar 27, 2024Observed: 32.29 ft at 2:31AM Mar 27, 2024Observed: 32.27 ft at 3:30AM Mar 27, 2024Observed: 32.29 ft at 4:28AM Mar 27, 2024Observed: 32.29 ft at 5:26AM Mar 27, 2024Observed: 32.27 ft at 6:25AM Mar 27, 2024Observed: 32.29 ft at 8:21AM Mar 27, 2024Observed: 32.27 ft at 10:18AM Mar 27, 2024Observed: 32.29 ft at 11:16AM Mar 27, 2024Observed: 32.29 ft at 12:15PM Mar 27, 2024Observed: 32.29 ft at 1:13PM Mar 27, 2024Observed: 32.29 ft at 2:11PM Mar 27, 2024Observed: 32.29 ft at 3:10PM Mar 27, 2024Observed: 32.29 ft at 4:08PM Mar 27, 2024Observed: 32.32 ft at 5:06PM Mar 27, 2024Observed: 32.32 ft at 6:05PM Mar 27, 2024Observed: 32.37 ft at 7:03PM Mar 27, 2024Observed: 32.42 ft at 8:01PM Mar 27, 2024Observed: 32.54 ft at 9:00PM Mar 27, 2024Observed: 32.54 ft at 9:58PM Mar 27, 2024Observed: 32.49 ft at 10:56PM Mar 27, 2024Observed: 32.54 ft at 11:55PM Mar 27, 2024Observed: 32.59 ft at 12:53AM Mar 28, 2024Observed: 32.79 ft at 1:51AM Mar 28, 2024Observed: 32.79 ft at 2:50AM Mar 28, 2024Observed: 32.79 ft at 3:48AM Mar 28, 2024Highest Observation: 32.84 ft at 4:46AM Mar 28, 2024PTMC1(plotting HGIRR) Graph Created (9:45AM Mar 28, 2024)ObservedLatest observed value: 32.84 ft at 4:46 AM PDT 28-Mar-2024. Flood Stage is 40.7 ft
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Tabular Data (UTC)
Tabular Data (PDT)
XML Data
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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.
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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
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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
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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  
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Page last modified: 2-Nov-2020 7:27 PM
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