River Report

Ashuelot River river

5 streamgauges 57% of normal Last updated 2026-05-25
Aggregate flow
1,021cfs
% of normal
57%
Daily volume
2,025AF
Seasonal avg
1,798cfs

Total streamflow across the Ashuelot River was last observed at 1,021 cfs, and is expected to yield approximately 2,025 acre-ft of water today; about 57% of normal. River levels are low and may signify a drought. Average streamflow for this time of year is 1,798 cfs, with recent peaks last observed on 2021-07-20 when daily discharge volume was observed at 11,380 cfs.

Maximum discharge along the river is currently at the Ashuelot River At Hinsdale reporting a streamflow rate of 646 cfs. However, the streamgauge with the highest stage along the river is the Ashuelot River Above The Branch with a gauge stage of 66.2 ft. This river is monitored from 5 different streamgauging stations along the Ashuelot River, the highest being situated at an altitude of 810 ft, the Ashuelot River Near Gilsum.

Max discharge

Ashuelot River At Hinsdale

646cfs
Highest stage

Ashuelot River Above The Branch

66.2ft
Highest-elevation gauge

Ashuelot River Near Gilsum

810ft
Aggregate trend

River streamflow levels

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

All 5 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)
Ashuelot River Near Gilsum NH
USGS 01157000
135 3.09 17.7 108% 2 6,840 810
Ashuelot River Below Surry Mt Dam NH
USGS 01158000
151 5.81 0.0 88% 0 1,210 502
Ashuelot River Above The Branch NH
USGS 01158110
21 66.20 -43.4 23% 0 1,260 476
Ashuelot River At West Swanzey NH
USGS 01160350
539 6.80 7.2 94% 18 4,080 456
Ashuelot River At Hinsdale NH
USGS 01161000
646 4.57 6.8 90% 27 6,940 205
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

Ashuelot River

The Ashuelot River is a 64-mile-long river in southwestern New Hampshire. The river flows through several towns, including Ashuelot, Winchester, Hinsdale, and Swanzey. The river's hydrology is largely influenced by the many dams and reservoirs along its length. The two largest reservoirs are the Highland Lake and the Surry Mountain Lake. The river has historically been used for water-powered mills, and today it is used for hydroelectric power generation. Additionally, the river provides opportunities for recreational activities such as fishing, canoeing, and kayaking. The river is also used for agricultural irrigation in some areas. The Ashuelot River is an important natural resource for the region and is home to a variety of fish species, including trout, smallmouth bass, and walleye.

Around the river

Recreation along the Ashuelot River

Fishing access and paddle runs Snoflo tracks within the watershed.

Track the Ashuelot 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 Ashuelot River

Where does the data for the Ashuelot 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.