Arrowhead Run at Thayerville Water Level
Live river level, flow, historical records and forecast for Arrowhead Run at Thayerville in MD, United States, built from official government gauge data.
- Location MD, United States
- Watershed youghiogheny
- Primary gauge 03075850 (USGS)
About Arrowhead Run at Thayerville
Arrowhead Run in the Youghiogheny watershed, Maryland, is a small USGS-gauged river with 1 sq mi (2.7 km2) upstream of the station.
The watershed
That catchment is the drainage area above this gauge, not the whole watershed name on the map. With only 1 sq mi (2.7 km2) feeding the station, the water can move quickly when rain falls over the basin.
In this part of Maryland, winter and spring are the seasons to watch for higher water, while summer is the lower-water stretch between storms. That is the pattern on the page, and it matches what cottagers and anglers notice at the bank: more water to manage early in the year, less margin in late summer.
What the numbers say
The record high is 3.5 ft (1.07 m) in April 2024. The record low is 2.49 ft (0.76 m) in August 2021.
The usual seasonal shape is modest but clear. February is the highest typical month at 2.97 ft (0.91 m), and August is the lowest typical month at 2.63 ft (0.8 m). The typical annual swing is 4.1 in (10.4 cm).
For someone using the run, that means the station usually changes by a small amount through the year, but the extremes still matter. A dock, crossing, or intake near the channel should be set with the February-to-August difference in mind, and the April 2024 high shows that the water can get noticeably above the usual seasonal range.
Reading the hero number
The hero number on this page should be read against the median for the same calendar day across the station record, not as a raw elevation. That comparison tells you whether today is running high or low for this date, which is the useful question for a river with more than 10 years of record at a USGS station.
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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The science of snow water equivalent and why it drives the season ahead.
What the numbers on the measuring stick actually tell you.
Why Central and South Texas rivers go from gravel beds to fifty-year records in an afternoon - including July 2026 on the Nueces.
One percent, every year, forever - unwrapping hydrology's most misunderstood phrase, and how it differs from our own percentiles.
How every number is computed - About the platform
