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Big Thompson River (CO) near La Salle

Highest listed crest 9.91 ftFlood stage 8.0 ft10 crests since 1980

The Big Thompson River (CO) near La Salle crested above flood stage 4 times among the 10 crests the National Weather Service lists from 1980 to 2021. The highest, 9.91 ft on May 1, 1980, was moderate flooding, 1.91 feet above flood stage. 1 other gauge on the Big Thompson River (CO) crested above flood stage within a week of it.

The gauge

Highest listed crest
9.91 ft
May 1, 1980; 6,220 cubic feet per second
Flood stage
8.0 ft
Major flooding from 11.0 ft
Crests at major
0
4 above flood stage
Most recent flood crest
June 5, 2015
8.79 ft, minor flooding
Location
Weld County
Near Evans (1.9 mi), Greeley (4.4 mi), Johnstown (7.4 mi)
Identifiers
NWS LSLC2
No USGS station

Flood stages

The thresholds the National Weather Service uses for this gauge today, and how many listed crests reached each.

Flood categories, Big Thompson River (CO) near La Salle
Action stage7.01Jun 13, 1997The level at which the NWS or its partners begin to take action
Flood stage (minor)8.02Jun 5, 2015Minimal or no property damage, but possibly some public threat
Moderate flood stage9.52May 1, 1999Some inundation of structures and roads near the stream
Major flood stage11.00—Extensive inundation of structures and roads

Every listed crest

10 crests from 1980 to 2021. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Big Thompson River (CO) near La Salle, 1980 to 2021 4681012ft Flood stage 8.0 ftMajor 11.0 ft May 1, 1980: 9.91 ft, moderate flooding; 6,220 cubic feet per secondMay 31, 1995: 9.47 ft, minor flooding; 6,706 cubic feet per secondJun 13, 1997: 7.01 ft, action stage; 2,622 cubic feet per secondMay 1, 1999: 9.54 ft, moderate flooding; 5,755 cubic feet per secondJun 4, 2005: 4.33 ft, below flood stage; 1,000 cubic feet per secondJun 13, 2010: 6.34 ft, below flood stage; 1,640 cubic feet per secondJun 1, 2014: 6.84 ft, below flood stage; 1,860 cubic feet per secondJun 5, 2015: 8.79 ft, minor flooding; 2,390 cubic feet per secondJun 13, 2016: 4.46 ft, below flood stage; 708 cubic feet per secondJun 8, 2021: 5.19 ft, below flood stage; 925 cubic feet per second Highest, 9.91 ft, May 1, 1980 19801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Big Thompson River (CO) near La Salle 1980s: 1 1990s: 2 2 2000s: 0 2010s: 1 2020s: 0 1980s1990s2000s2010s2020s
  1. These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor.
  2. Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable.

Highest crests

Highest listed crests, Big Thompson River (CO) near La Salle
1May 1, 19809.91+1.91Moderate6,220
2May 1, 19999.54+1.54Moderate5,755
3May 31, 19959.47+1.47Minor6,706
4Jun 5, 20158.79+0.79Minor2,390
5Jun 13, 19977.01−0.99Action2,622
6Jun 1, 20146.84−1.16Below flood stage1,860
7Jun 13, 20106.34−1.66Below flood stage1,640
8Jun 8, 20215.19−2.81Below flood stage925
9Jun 13, 20164.46−3.54Below flood stage708
10Jun 4, 20054.33−3.67Below flood stage1,000

The worst floods along the Big Thompson River (CO)

For this gauge's highest crests, the other gauges on the Big Thompson River (CO) that crested above flood stage within a week.

May 1, 1980: 9.91 ft here, moderate flooding

  • LovelandCO · Apr 30, 1980 · 10.10 ft · Minor

May 1, 1999: 9.54 ft here, moderate flooding

  • LovelandCO · Apr 30, 1999 · 10.48 ft · Minor

Gauges on the Big Thompson River (CO)

Flood gauges sharing the river's name, linked within 80 miles of one another.

Flood gauges on the Big Thompson River (CO)
LovelandCO10.011.93 ft, Sep 13, 20131
Lake EstesCO6.59.05 ft, Sep 12, 20131
La Salle this gaugeCO8.09.91 ft, May 1, 19800

Other gauges in Weld County

Flood gauges in Weld County
Greeley8.58.73 ft, Jun 3, 20140
Greeley8.09.25 ft, Sep 15, 20130
Platteville9.010.03 ft, May 10, 20150
Kersey10.015.09 ft, Sep 14, 20131

Weld County: every hazard · River floods across the country · Colorado

NOAA National Water Prediction Service, gauge LSLC2, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.