Big Sioux River near Watertown Water Level
Live river level, flow, historical records and forecast for Big Sioux River near Watertown in SD, United States, built from official government gauge data.
- Location SD, United States
- Watershed upper big sioux
- Primary gauge 06479438 (USGS)
About Big Sioux River near Watertown
The Big Sioux River near Watertown is in the Upper Big Sioux watershed in South Dakota.
What the record shows
This station has 50 years on record. The high-water mark is 11.64 ft (3.55 m), set in April 2023. The low-water mark is 3.65 ft (1.11 m), set in August 2021.
The seasonal pattern is straightforward: the typical high month is April at 5.39 ft (1.64 m), and the typical low month is September at 4.06 ft (1.24 m). That gives a typical annual swing of 16 in (40.6 cm). For anyone with a dock, intake, or low bank crossing, that is the range to expect the river to work through in an average year.
Spring is the month to watch most closely here. In Prairie hydrology, snowmelt is the defining event, and this record shows April as the high month. Summer sits lower, with September as the typical minimum.
The watershed
The gauge drains 525 sq mi (1,360 km2) above the station. That is the area feeding this site, not the full named watershed on the map.
For neighbours upstream and downstream, that matters because this station reflects what is happening across that contributing area. The river can rise well beyond its typical April level, as it did in April 2023, and it can also fall well below the usual September level, as it did in August 2021.
Reading the hero number
The number on this page is most useful when you compare today’s reading with the median for the same calendar day across the station record. That tells you whether the river is running high or low for this date, instead of just showing a single elevation.
This station is a USGS site with 50 years on record, so the calendar-day median is a better reference than the raw reading alone.
How this page is built
Readings come from official government gauges and are rolled into daily records: the daily mean, high and low for every day on record. Each calendar day gets its own baseline from the full history, so the level you see is compared against what this specific date usually looks like rather than an annual average.
How Nibi Metrics works · Water stories
Nibi Metrics - live water levels, flow, and forecasts for lakes and rivers across Canada, the US and the UK
Real-time water levels, forecasts, and alerts for lakes and rivers across Canada, the US and the UK. Built on official government data.
Nibi Metrics tracks more than 13,000 gauged lakes and rivers across Canada, the United States and the United Kingdom, reading directly from official federal monitoring networks: the Water Survey of Canada, the United States Geological Survey, Quebec's provincial hydrometric network, and the Environment Agency for England. Every number on the platform is measured, not modelled - taken from a government gauge on the water itself and compared against that location's own historical record for this exact date.
What you can see for any monitored lake or river
The level right now, in feet or metres, updated as the source agency publishes new readings - for many stations that is every five to fifteen minutes. How today compares to typical: every location carries its own typical-for-this-date band built from its historical record, so a reading is never just a number - it is above, below, or near what this water usually does on this calendar day. Which way it is moving: a measured RISING, FALLING, or STEADY verdict computed from the gauge's own recent readings, with the rate of change - the difference between a flood ending and one beginning. What comes next: level forecasts up to 72 hours ahead, driven by the gauge's recent behaviour, upstream water, and quantitative precipitation forecasts, alongside live radar, lightning, and weather for the surrounding region.
Alerts that watch the water for you
Set a threshold on any location - a level, a distance above typical, or a rate of climb - and Nibi emails or notifies you the moment the gauge crosses it. Cottagers use it for spring freshet, anglers for river conditions, marinas and municipalities for operations. The scanning runs around the clock against the same measured data shown on every page.
Where Nibi comes from
Nibi means water in Anishinaabemowin. The platform began at a family cottage on Lake Muskoka, Ontario, where the spring melt floods the shoreline most years and the only forecast was standing on the dock, looking, and guessing. It grew into an independent, member-funded platform run by Muskoka Research Inc. - no investors, no data resale, and a privacy policy shorter than most cookie banners. The core data is free for everyone, forever; paid plans add automation like multi-location alerts, deep history, and reports.
Coverage
Nibi spans the continent: every Canadian province and territory with active federal gauges - from Vancouver Island rivers to the Muskoka lakes, prairie reservoirs, and Quebec's hydrometric network - and the United States from Maine to the Texas Hill Country, the Ohio Valley, and the Pacific Northwest. Coverage grows where the water news is: when a basin floods, its gauges join the platform with their full historical records attached. Many stations report every five to fifteen minutes; most report at least hourly; every page states exactly when its gauge last spoke.
Free forever, funded by members
The core promise is simple: the water data is free, for everyone, forever. Live levels, maps, radar, and recent history never sit behind a paywall. Paid plans fund the platform by adding automation - multi-location alerts, decades of history, longer forecasts, and PDF reports - so the people who need more carry the cost for everyone who just needs to check the lake before driving up. There are no investors and no advertising deals shaping what the data says.
Water Stories
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How every number is computed - About the platform
