River Report

Tualatin River river

2 streamgauges 61% of normal Last updated 2026-05-19
Aggregate flow
585cfs
% of normal
61%
Daily volume
1,160AF
Seasonal avg
956cfs

Total streamflow across the Tualatin River was last observed at 585 cfs, and is expected to yield approximately 1,160 acre-ft of water today; about 61% of normal. River levels are low and may signify a drought. Average streamflow for this time of year is 956 cfs, with recent peaks last observed on 2015-12-12 when daily discharge volume was observed at 15,370 cfs.

Maximum discharge along the river is currently at the Tualatin River At West Linn reporting a streamflow rate of 397 cfs. However, the streamgauge with the highest stage along the river is the Tualatin River Near Dilley with a gauge stage of 10.02 ft. This river is monitored from 2 different streamgauging stations along the Tualatin River, the highest being situated at an altitude of 168 ft, the Tualatin River Near Dilley.

Max discharge

Tualatin River At West Linn

397cfs
Highest stage

Tualatin River Near Dilley

10.02ft
Highest-elevation gauge

Tualatin River Near Dilley

168ft
Aggregate trend

River streamflow levels

Daily aggregate streamflow across every monitored gauge along the Tualatin River. Use the range buttons to zoom in on a specific period.

Total streamflow

Sum of all monitored streamgauges · daily

Per-gauge breakdown

Every streamgauge along the Tualatin River

All 2 USGS gauges Snoflo tracks for this river, with current flow, stage, recent change, percent of normal, and the gauge's all-time min / max. Click any header to sort. Cells are heatmapped relative to the column min/max -- darker blue = higher.

Streamgauge Streamflow (cfs) Gauge stage (ft) 24h Δ (%) % Normal Min (cfs) Max (cfs) Elevation (ft)
Tualatin River Near Dilley OR
USGS 14203500
96 10.02 -4.9 55% 51 17,100 168
Tualatin River At West Linn OR
USGS 14207500
397 3.41 -13.5 52% 143 26,400 110
Annual peaks

Maximum streamflow discharge by year

The single highest aggregate discharge recorded each year. Spotting the multi-year trend reveals droughts vs. wet cycles long before the headline daily flow does.

Annual peak discharge

From the river's full record · one point per water year

Profile

Streamflow elevation profile

Each bubble is one gauge along the river, plotted by current streamflow (x-axis) vs elevation (y-axis), sized by gauge stage. Reading top-to-bottom traces the river from headwaters down to its mouth -- you can see flow accumulate as elevation drops.

Elevation vs streamflow

One point per monitored gauge · bubble size = gauge stage

About this river

Tualatin River

The Tualatin River is a 83-mile long river located in Oregon, United States. It has a rich history, being home to indigenous people for thousands of years, and later used by early pioneers for transportation and agriculture. The river's hydrology is heavily influenced by precipitation and snowmelt, with flow peaking in the winter months. The river is impounded by several dams, including the Hagg Lake Dam and Barney Reservoir Dam, which provide flood control and recreational opportunities. The river is also used for agricultural purposes, with many farms located along its banks. Recreational activities include fishing, boating, and wildlife viewing. Despite ongoing efforts to improve water quality, the river has been plagued by pollutants in the past, and remains a focus of conservation efforts.

Around the river

Recreation along the Tualatin River

Fishing access and paddle runs Snoflo tracks within the watershed.

Track the Tualatin River in the Snoflo app

Set per-gauge push alerts (e.g. "alert me when flow at the Russian R Nr Healdsburg crosses 5,000 cfs"), and Snoflo's iOS app pushes the moment USGS reports the crossing.

FAQ

About the Tualatin River

Where does the data for the Tualatin River come from?

Streamflow and gauge stage data are sourced from the U.S. Geological Survey (USGS) National Water Information System. The aggregate flow shown at the top of the page is computed by Snoflo as the sum of all monitored gauges along the river.

How is "percent of normal" calculated?

Today's aggregate streamflow is compared to the historical average aggregate streamflow on this calendar day across the river's full record. 100% means right on average; values above 100% indicate above-normal flow (wet year); values below indicate below-normal (dry year or drought).

Why are some gauges showing very different flows?

Gauges along a river measure flow at different points: headwater gauges read what's coming off the snowpack or mountain runoff; downstream gauges integrate everything upstream, including tributary inputs. Wide spreads usually mean a tributary is contributing significantly between gauges.

What's the elevation profile chart showing?

Each bubble is one gauge along the river, plotted by streamflow (x-axis) and elevation (y-axis), sized by gauge stage. Reading top-down traces the river from headwaters to mouth -- you can see flow build as elevation drops.

Can I get alerts when a specific gauge crosses a threshold?

Yes -- alerts are managed in the Snoflo iOS app on a per-gauge basis. Open any individual streamgauge from the table above and favorite it to set a discharge threshold.