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Hydrograph River at a Glance Download
Sage Creek at Lake Hennessey Stage (ft)Highest Observation: 1.11 ft at 1:07PM May 13, 2024Highest Observation: 1.11 ft at 1:10PM May 13, 2024Observed: 1.1 ft at 1:10AM May 14, 2024Observed: 1.1 ft at 1:10PM May 14, 2024Observed: 1.1 ft at 1:10AM May 15, 2024Observed: 1.1 ft at 1:10PM May 15, 2024Observed: 1.1 ft at 1:07AM May 16, 2024Observed: 1.1 ft at 1:10AM May 16, 2024Observed: 1.09 ft at 1:10PM May 16, 2024Observed: 1.1 ft at 1:07AM May 17, 2024Observed: 1.1 ft at 1:10AM May 17, 2024Observed: 1.08 ft at 1:07PM May 17, 2024Observed: 1.08 ft at 1:10PM May 17, 2024Observed: 1.09 ft at 1:07AM May 18, 2024Observed: 1.09 ft at 1:10AM May 18, 2024SBSC1(plotting HGIRR) Graph Created (12:45PM May 18, 2024)ObservedLatest observed value: 1.09 ft at 1:10 AM PDT 18-May-2024. Flood Stage is 13.3 ft
About this graph
Tabular Data (UTC)
Tabular Data (PDT)
XML Data
RSS Files
Datum: Not Available
NOTE: Graphical forecasts are not available for the Sage Creek at Lake Hennessey. 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: 12
Moderate Flood Stage: 10
Flood Stage: 9
Action Stage: 7
Low Stage (in feet): -9999

Historic Crests
Currently none available.

Recent Crests
Currently none available.

Low Water Records
Currently none available.
Zoom Level:16
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Gauge LocationGauge Map Marker
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
12 Major flood stage. Water is approximately 2 feet deep on Highway 128 and surrounding floodplain. Travel severely restricted or impossible and dangerous along Highway 128.
10 Moderate flood stage. Water inundates floodplain, bridge deck at private driveway, and Highway 128. NWS will issue a Flash Flood Warning if not yet already issued.
9 Minor flood stage. Flows begin to backwater at private driveway bridge crossing at gaging site. NWS may issue an urban/small stream advisory if not already issued.
7 Monitor stage. Water is 2 feet below backwater conditions at private driveway at stream gaging site. NWS may issue a Flash Flood Watch if not yet already issued.
About This Location Collapse

Latitude: 38.491389° N, Longitude: 122.335278° W, Horizontal Datum: NAD83/WGS84

River Stage
Reference Frame
Gauge Height Flood Stage Uses
NWS stage 0 ft 9 ft Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps
Vertical Datum Elevation
(gauge height = 0)
(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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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
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Page last modified: 2-Nov-2020 7:27 PM
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