Rivermatics

USGS Streamgage 06730525

St Vrain Creek below Boulder Creek at Hwy 119 near Longmont

St Vrain Creek below Boulder Creek at Hwy 119 near Longmont is USGS streamgage 06730525 in Colorado, monitoring river discharge in hydrologic subbasin 10190005. It drains a watershed of about 872 square miles. Discharge records at this site go back to 2013. Typical flow runs near 128.1 cfs in July and 125.9 cfs in April, with the higher of the two arriving in July. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead.

View live conditions & forecast →

Gauge details

State
Colorado
Drainage area
872 sq mi
Gauge elevation
4,849 ft
Subbasin (HUC-8)
10190005
Coordinates
40.16047, -105.00794
USGS site number
06730525
Records begin
2013-09-19 (13 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for St Vrain Creek below Boulder Creek at Hwy 119 near Longmont. Each day carries a median estimate and the band the model expects the flow to fall within — not a single number to plan against. Forecasts are re-issued daily; see the live screen for the current outlook.

Forecast daily mean discharge in cubic feet per second, by date
Date Low p10 Expected p50 High p90 Range
35.2 40.4 45.1
30.8 38.4 46.7
28.4 37 48.1
27.9 37.8 53.2
26.3 37.6 55.4
28.9 42.8 67.6
30.5 45.6 70.4
30.9 47.3 72.8
22.1 34.9 55.9
19.4 31 50
18.6 29.9 48.7
17.7 28.3 46.2
17.1 28 47.9
17.2 28.2 49

All values in cubic feet per second (cfs). Estimates only — do not use them for navigation or for any safety, rescue, or emergency decision.

Typical flow by month

Long-term daily discharge percentiles from the USGS record (up to 13 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.

Historical monthly discharge percentiles in cubic feet per second
Month Low p10 Typical p50 High p90 Range
January 59.6 98.4 135.4
February 57.6 100.7 155.8
March 65 108.4 264.2
April 62.7 125.9 444.4
May 113.6 393.6 1,736
June 218.8 637.1 2,142.5
July 77.9 128.1 578.5
August 66 98.9 206
September 55.8 90.7 568.8
October 59.3 111.6 451.9
November 76.4 113.6 289.6
December 68.3 108.7 188.5

All values in cubic feet per second (cfs).

Common questions

When does St Vrain Creek below Boulder Creek at Hwy 119 near Longmont normally run highest?
June, on the long-term record. The median daily flow that month is about 637.1 cfs, against 90.7 cfs in September, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for St Vrain Creek below Boulder Creek at Hwy 119 near Longmont?
It depends on the month. In January, half of days historically fall near 98.4 cfs, with the middle 80% of days between 59.6 and 135.4 cfs. The month-by-month table on this page gives the full range.
How long has St Vrain Creek below Boulder Creek at Hwy 119 near Longmont been measured?
Discharge records at USGS site 06730525 begin in 2013, about 13 years, covering roughly 4,704 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for St Vrain Creek below Boulder Creek at Hwy 119 near Longmont?
Yes. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on this basin's observed flows, weather, and snowpack, and issues a daily flow outlook reaching 14 days ahead: a median estimate inside a confidence band, not a single number to bet on. Every forecast is scored against days the model never trained on, and that track record is published on the live gauge screen. Open live conditions to see the current outlook.
Where is St Vrain Creek below Boulder Creek at Hwy 119 near Longmont?
The gauge sits at 40.16047, -105.00794, in Colorado, in hydrologic subbasin 10190005, at an elevation of about 4,849 feet, draining roughly 872 square miles.
Can I use St Vrain Creek below Boulder Creek at Hwy 119 near Longmont data for flood or safety decisions?
No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.

Other gauges in this subbasin