River Report

Mongaup River river

2 streamgauges 81% of normal Last updated 2026-05-31
Aggregate flow
260cfs
% of normal
81%
Daily volume
515AF
Seasonal avg
320cfs

Total streamflow across the Mongaup River was last observed at 260 cfs, and is expected to yield approximately 515 acre-ft of water today; about 81% of normal. Average streamflow for this time of year is 320 cfs, with recent peaks last observed on 2021-10-28 when daily discharge volume was observed at 4,956 cfs.

Maximum discharge along the river is currently at the Mongaup River Near Mongaup Ny reporting a streamflow rate of 203 cfs. However, the streamgauge with the highest stage along the river is the Mongaup River At Mongaup Valley Ny with a gauge stage of 3.11 ft. This river is monitored from 2 different streamgauging stations along the Mongaup River, the highest being situated at an altitude of 1,069 ft, the Mongaup River At Mongaup Valley Ny.

Max discharge

Mongaup River Near Mongaup Ny

203cfs
Highest stage

Mongaup River At Mongaup Valley Ny

3.11ft
Highest-elevation gauge

Mongaup River At Mongaup Valley Ny

1,069ft
Aggregate trend

River streamflow levels

Daily aggregate streamflow across every monitored gauge along the Mongaup 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 Mongaup 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)
Mongaup River At Mongaup Valley Ny NY
USGS 01432900
57 3.11 -19.2 66% 12 4,470 1,069
Mongaup River Near Mongaup Ny NY
USGS 01433500
203 1.91 -4.7 133% 12 3,960 626
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

Mongaup River

The Mongaup River is a 20-mile-long river located in Sullivan and Orange Counties in New York. The river starts at the Mongaup Pond in the Catskill Mountains and flows into the Delaware River. The Mongaup River has a rich history, having been used for logging and fishing in the past. The river is also an important source of drinking water for several communities. The river has several reservoirs and dams, including the Rio Dam and the Mongaup Falls Reservoir. These reservoirs help regulate the flow of the river and provide hydroelectric power. The Mongaup River is a popular destination for recreational activities such as fishing, kayaking, and camping. The river is also used for agricultural purposes, including irrigation and livestock watering.

Track the Mongaup 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 Mongaup River

Where does the data for the Mongaup 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.