Gage height · USGS gauge 06821140 · updated August 29, 2026
Smithville Lake by Dam Water LevelDWater-quality grade D
The USGS gauge at Smithville Reservoir near Smithville, MO last recorded a gage height of 863.72 ft at Smithville Lake by Dam on August 29, 2026. In Clay County, Missouri, Smithville Lake by Dam carries an overall water-quality grade of D. Water clarity averages 3.3 feet of visibility, and there is one public boat landing on the lake. The water-quality samples behind that grade were submitted to the EPA Water Quality Portal by Univ. of Missouri, Columbia; the level above comes from the USGS, which runs the gauge.
Gage height
863.72ft
feet on the station datum
Gauge 06821140, Smithville Reservoir near Smithville, MO, operated by the U.S. Geological Survey. The value above is the most recent reading on file with its own timestamp. When the gauge answers, it is replaced by the current one — no estimate is ever shown in place of a missing reading.
What this number is
Gage height is the height of the water above a reference point set at Smithville Reservoir near Smithville, MO when the station was installed. It tracks rise and fall at this lake accurately, but the zero point is local: it is not depth, not sea level, and not comparable to another lake's gage height.
- Measured as
- Gage height, ft on the station datum
- Most recent reading on file
- 863.72 ft · August 29, 2026
- Water quality
- DGrade D
No target level is shown here. Saying a lake is high or low needs a conservation pool or a seasonal rule curve to measure against, and the gauge reading alone does not carry one. The station page above holds the full record, including the last several days, which is what a single reading has to be read against.
Surface elevation is a different number
Mapped surface elevation at Smithville Lake by Dam is about 863 feet above sea level, from the HydroLAKES global lake dataset. That is a fixed cartographic value, not a reading: it does not move when the lake rises, and it is not the gage height above. Keep the two apart.
Water quality at Smithville Lake by Dam
Smithville Lake by Dam grades D on total phosphorus, total nitrogen, chlorophyll-a, and turbidity, measured against the EPA National Lakes Assessment condition classes for its own ecoregion. Clarity averages 3.3 feet of visibility — shown, not scored.
The gauge measures how much water is in the lake. The grade measures what is in the water. A rise or a drawdown does not change the letter until the lake is sampled again.
Common questions
What is the water level at Smithville Lake by Dam right now?
The most recent reading from the USGS gauge at Smithville Reservoir near Smithville, MO is a gage height of 863.72 ft, taken on August 29, 2026. This page reloads that gauge every time it is opened, so the number above is the current one whenever the station is reporting. USGS lake gauges typically post a new value every 15 to 60 minutes.
What does gage height mean?
Gage height is the height of the water above a reference point set at Smithville Reservoir near Smithville, MO when the station was installed. It tracks rise and fall at this lake accurately, but the zero point is local: it is not depth, not sea level, and not comparable to another lake's gage height.
Is Smithville Lake by Dam low?
That question needs a target pool level to answer, and the gauge reading alone does not supply one. Reservoir operators publish a conservation pool or a seasonal rule curve for the lakes they manage, and the USGS station page for gauge 06821140 carries the full record this reading came from, including the past several days. Comparing today against that record is the honest version of "low" — a single number is not.
Does the water level affect water quality at Smithville Lake by Dam?
Smithville Lake by Dam carries an overall water-quality grade of D. Lakes are graded A to F on nutrients and algae — total phosphorus, total nitrogen, chlorophyll-a, and turbidity — measured against the EPA National Lakes Assessment 2022 condition classes for that lake's own ecoregion, so a lake is judged against the lakes it would naturally resemble. None of that comes from the gauge. A drawdown can concentrate nutrients and a heavy inflow can dilute them, but neither shows up in the grade until the water is sampled again. Treat the two numbers as separate measurements of the same lake.
Where these numbers come from
The level and temperature are U.S. Geological Survey instantaneous values from gauge 06821140, a public feed with no licence restriction. The water-quality grade is built from EPA Water Quality Portal samples submitted by Univ. of Missouri, Columbia. For advisories and standards in Missouri, Missouri DNR is the authority — a gauge reading is neither.