River Report

Grand River river

12 streamgauges 83% of normal Last updated 2026-05-24
Aggregate flow
22,335cfs
% of normal
83%
Daily volume
44,301AF
Seasonal avg
26,854cfs

Total streamflow across the Grand River was last observed at 22,335 cfs, and is expected to yield approximately 44,301 acre-ft of water today; about 83% of normal. Average streamflow for this time of year is 26,854 cfs, with recent peaks last observed on 2017-04-07 when daily discharge volume was observed at 240,121 cfs.

Maximum discharge along the river is currently at the Grand River Near Sumner reporting a streamflow rate of 10,100 cfs. This is also the highest stage along the Grand River, with a gauge stage of 23.64 ft at this location. This river is monitored from 12 different streamgauging stations along the Grand River, the highest being situated at an altitude of 10,170 ft, the Grand River Ditch At La Poudre Pass.

Max discharge

Grand River Near Sumner

10,100cfs
Highest stage

Grand River Near Sumner

23.64ft
Highest-elevation gauge

Grand River Ditch At La Poudre Pass

10,170ft
Aggregate trend

River streamflow levels

Daily aggregate streamflow across every monitored gauge along the Grand 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 Grand River

All 12 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)
Grand River Ditch At La Poudre Pass CO
USGS 09010000
39 0.89 9.6 91% 0 288 10,170
Grand R At Little Eagle Sd SD
USGS 06357800
99 3.02 22.3 48% 0 14,400 1,640
Grand River At Jackson MI
USGS 04109000
158 10.09 -25.5 93% 24 835 911
Grand River Near Eaton Rapids MI
USGS 04111000
1,400 4.79 10.2 154% 84 3,860 855
Grand River At Lansing MI
USGS 04113000
809 3.53 8.2 57% 69 10,200 808
Grand River Near Gallatin MO
USGS 06897500
3,960 10.28 -21.1 284% 3 73,700 740
Grand River At Portland MI
USGS 04114000
930 5.88 6.3 60% 136 10,800 719
Grand River At Chillicothe MO
USGS 06899680
361 6.97 · · · · 686
Grand River Near Sumner MO
USGS 06902000
10,100 23.64 -35.3 387% 13 127,000 636
Grand River At Ionia MI
USGS 04116000
1,630 9.75 4.5 62% 277 24,600 620
Grand River Near Painesville Oh OH
USGS 04212100
1,250 4.10 174.1 409% 12 16,700 596
Grand River At Grand Rapids MI
USGS 04119000
3,360 3.37 -3.5 67% 590 34,900 587
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

Grand River

The Grand River is a 300-kilometer long river that runs through southern Ontario, Canada. It was an important waterway for Indigenous peoples and European explorers and was later used for transportation and industry. The river originates in the highlands of Dufferin County and flows into Lake Erie at Port Maitland. The river’s hydrology is affected by numerous tributaries and reservoirs, including the Conestogo, Speed, and Eramosa rivers, and the Elora and Guelph Lake reservoirs. There are also several dams along the river, including the Shand Dam and the Guelph Lake Dam. The Grand River is used for water supply, flood control, and hydroelectric power generation. It is also a popular destination for recreational activities such as fishing, boating, and camping. The river is also home to several agricultural operations, including dairy farms and crop production.

Track the Grand 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 Grand River

Where does the data for the Grand 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.