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Hydrograph River at a Glance Download
Saint Vrain Creek below Longmont Stage (ft)USGS--Water Resources of the United StatesSVLC2(plotting HGIRG) Graph Created (8:15PM May 22, 2024)ObservedFlood Stage is 15.5 ft
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Tabular Data (UTC)
Tabular Data (MDT)
XML Data
RSS Files
Datum: NAVD88
NOTE: Stage may be affected by ice during winter months.

NOTE: Forecasts are not available for the Saint Vrain Creek below Longmont. Only observed stages are available for this point.

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Upstream Gauge - at Hygiene Upstream Gauge Downstream Gauge Downstream Gauge - near Platteville
Flood Categories (in feet)
Major Flood Stage: 18.5
Moderate Flood Stage: 17
Flood Stage: 15.5
Action Stage: 15
Low Stage (in feet): -9999

Historic Crests
(1) 14.56 ft on 05/09/2015
(2) 13.44 ft on 05/18/2017
(3) 12.97 ft on 06/01/2014
(4) 12.24 ft on 07/02/2019
(5) 12.17 ft on 06/14/2016
(6) 12.08 ft on 06/07/2021
(7) 11.31 ft on 06/19/2018
(8) 11.20 ft on 06/06/2020

(P): Preliminary values subject to further review.

Recent Crests
(1) 12.08 ft on 06/07/2021
(2) 11.20 ft on 06/06/2020
(3) 12.24 ft on 07/02/2019
(4) 11.31 ft on 06/19/2018
(5) 13.44 ft on 05/18/2017
(6) 12.17 ft on 06/14/2016
(7) 14.56 ft on 05/09/2015
(8) 12.97 ft on 06/01/2014

(P): Preliminary values subject to further review.

Low Water Records
Currently none available.

For more information on your flood risk go to

Zoom Level:14
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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
18.5 Major, extensive flooding occurs as a wide expanse of the creek spreads out horizontally across the floodplain.
17.5 Flooding affects large areas along the creek with numerous roads and structures impacted.
16.5 There is significant flooding of agricultural land along the creek.
15.5 Parks and agricultural fields and parks near the creek flood. Railroad tracks may be impacted.
15 Water begins to overflow into the lowest areas adjacent to Saint Vrain Creek below its confluence with Boulder Creek.
About This Location Collapse

Latitude: 40.160500° N, Longitude: 105.007900° W, Horizontal Datum: NAD83/WGS84

River Stage
Reference Frame
Gauge Height Flood Stage Uses
NWS stage 0 ft 15.5 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 4849 4864.5 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 U.S. Geological Survey

Current/Historical Observations:

Additional Information Collapse
Observations provided by the U.S. Geological Survey in cooperation with the City of Longmont
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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
Denver/Boulder Weather Forecast Office
325 Broadway
Boulder, CO 80305-3328
(303) 494-4221
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Page last modified: 2-Nov-2020 7:28 PM
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