What's happening?
This fall (2026), the Army Corps of Engineers plans to lower the water level in the Detroit Dam reservoir through a process called a “deep drawdown.”
The Goal: To improve fish passage through the dam.
As the water level drops, sediment behind the dam will be stirred up, making the North Santiam River much murkier with sediment—potentially affecting the ecology and drinking water treatment systems downstream.
There are current legal filings between cities along the North Santiam River and the U.S. Army Corps of Engineers seeking to prevent the deep drawdown from happening.
This site brings together independent river readings, official updates, and articles to help keep the public informed.
Official 2026 timing update
Residents should come back often as the window approaches. Follow recent news, events, and litigation updates.
Or sign up for USGS WaterAlert to receive turbidity updates.
One connected river
From Detroit and Idanha to Salem and Turner, ten communities depend on the North Santiam watershed. Much of that water is treated with sand filtration, a proven system that works best when excess solids and silt stay low.
Choose a marker to understand a place on the river. Numbered stations show our demonstration dataset; five USGS gauges show live provisional federal readings. Seeing both on one map makes it easier to understand what changed, where, and when.
What changed?
Published field data appears below. Draft samples remain private until an administrator reviews and publishes them. Stations without a published sample remain marked TBD.
Cloudiness caused by suspended particles
Compare the demonstration samples at Detroit Lake with live provisional USGS turbidity data from below Stout Creek near Mehama. This station sits above Detroit Dam while the gauge sits well below it, so read these as the two ends of the drawdown — reservoir conditions going in, river conditions coming out — not as the same water sampled twice.
Loading federal gauge history…
These methods answer a similar question but use different light sources: USGS reports FNU and the demonstration samples use NTU. The values may move together, but they are not interchangeable, so we keep each series separate.
Gauge 14183020Why shared facts matter
The U.S. Army Corps of Engineers, which owns and operates Detroit Dam, plans a deep drawdown of Detroit Reservoir to give endangered salmon and steelhead safer downstream passage. Lowering a reservoir that far can stir up decades of accumulated sediment and release it into the North Santiam.
That river is not just scenery. It has been Salem's primary water supply for more than 80 years, and it is treated at Geren Island near Stayton using slow sand filtration—a naturally-driven process in use since the 1930s that depends on consistently clean source water. Sustained high turbidity is exactly the condition that process handles worst, and in a worst case it can force treatment to pause.
On July 8, 2026, the City of Salem filed a federal lawsuit against the Corps in U.S. District Court in Oregon. A central claim: the Corps never delivered a turbidity impact report owed to Congress under the Water Resources Development Act of 2024. Salem is asking a court to compel that analysis and set enforceable safeguards—like sediment thresholds that would pause or adjust the drawdown.
Fish passage is a genuine legal and ecological obligation, and reliable drinking water for roughly 220,000 people is a shared community need. A transparent record of turbidity from the reservoir to Jefferson gives residents, utilities, wildlife advocates, and decision-makers the same facts to work from.
Turbidity is cloudiness from suspended silt. It is not itself toxic, but it interferes with treatment and disinfection, and particles can shelter microorganisms from it. A large, sustained spike from a drawdown is a real operational problem for a river-fed slow sand plant—which is why it is the measurement the lawsuit turns on, and the one we track most closely.
Detroit and Idanha sit above the dam, so downstream turbidity does not reach their source water the same way. Gates, Mill City, Lyons, Mehama, Stayton, Jefferson and Salem draw from or near the river below it. Our stations span both sides so the difference is visible, not assumed.
The passage requirements behind the drawdown protect threatened salmon and steelhead. Clear sediment data helps communities understand whether that work is proceeding alongside dependable drinking-water treatment.
The 760-square-mile North Santiam watershed is largely undeveloped forest, which is why the water arrives clean enough for a sand filtration method. Slow sand beds clean water through a living biological layer rather than chemicals, and heavy suspended solids clog that bed—cutting flow rates, driving more frequent backwashing, and shortening how long the media lasts. Sediment is the one variable capable of undoing that advantage quickly.
Samples are organized by place, date, and measurement so residents, reporters, utilities, and river advocates can begin with the same clearly labeled information.
This page brings in live provisional readings from five U.S. Geological Survey gauges—reservoir elevation at Detroit Lake, plus flow, temperature, pH, and continuous turbidity between Niagara and Jefferson. Each value is checked against its timestamp. Readings older than four hours are withheld, including values returned from retired sensors, so stale data is never presented as current.
For your health, follow all the instructions provided by your water purveyor. They will provide you with the appropraite information you need for your specific water system.
Who this information serves
This site is built for residents, water customers, river users, and local leaders in Detroit, Mill City, Gates, Stayton, Salem, Jefferson, and Aumsville, as well as neighboring North Santiam communities. Their locations and water systems differ, but changes at Detroit Reservoir can matter across the connected watershed.
River conditions shown here are informational. Follow your local utility and public health agency for drinking-water notices and emergency guidance.
Official sources and updates
Public Health Division · USGS WaterAlert
USGS WaterAlert can notify you the moment a monitored gauge you choose crosses a turbidity level you set—so you do not need to keep checking this page during the drawdown window.
Your water deserves a clear answer
River monitoring shows what is happening across the region. Testing your own water gives you results specific to your home, well, or business—so you can understand what is there and choose your next step with confidence.
Professional testing from Waterlab Corp