Water elevation · USGS gauge 08109900 · updated August 29, 2026
Water elevation
237.54ft
feet above sea level
Gauge 08109900, Somerville Lake near Somerville, TX, 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
Water elevation is the height of the lake surface above sea level, as surveyed at Somerville Lake near Somerville, TX. It is the number reservoir operators publish, and it is comparable from one reading to the next at this lake. It is not the depth of the water.
- Measured as
- Water elevation, ft above sea level
- Most recent reading on file
- 237.54 ft · August 29, 2026
- Water quality
- Readings on the lake page
The Corps of Engineers reads Somerville Lake at 236.71 ft, 1.29 ft below its Top of Conservation of 238.00 ft.
Both numbers come from the U.S. Army Corps of Engineers for its Somerville Lake project, on that project's own vertical datum (NGVD-29). That figure is a fixed level rather than a seasonal target, so a reservoir drawn down on purpose in autumn can sit well under it and still be exactly where the Corps intends. Because the datum is the project's own, this elevation is comparable to its own reference and to nothing else — not to a gauge reading from another agency, and not to a lake's mapped surface elevation.
Water quality at Somerville Lake Big Creek Arm
Somerville Lake Big Creek Arm's readings for total phosphorus, total nitrogen, chlorophyll-a, and turbidity are shown beside the EPA National Lakes Assessment condition classes for its own ecoregion. Clarity averages 1.8 feet of visibility, shown separately.
The gauge measures how much water is in the lake. The nutrient and algae readings measure what is in the water. A rise or a drawdown does not change those readings until the lake is sampled again.
Full water-quality breakdown for Somerville Lake Big Creek Arm
Common questions
What is the water level at Somerville Lake Big Creek Arm right now?
The most recent reading from the USGS gauge at Somerville Lake near Somerville, TX is a water elevation of 237.54 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 water elevation mean?
Water elevation is the height of the lake surface above sea level, as surveyed at Somerville Lake near Somerville, TX. It is the number reservoir operators publish, and it is comparable from one reading to the next at this lake. It is not the depth of the water.
Is Somerville Lake Big Creek Arm low?
Somerville Lake Big Creek Arm stood at 236.71 ft on September 27, 2026, 1.29 ft below its Top of Conservation of 238.00 ft. Both numbers come from the U.S. Army Corps of Engineers for its Somerville Lake project, on that project's own vertical datum (NGVD-29). That figure is a fixed level rather than a seasonal target, so a reservoir drawn down on purpose in autumn can sit well under it and still be exactly where the Corps intends. Because the datum is the project's own, this elevation is comparable to its own reference and to nothing else — not to a gauge reading from another agency, and not to a lake's mapped surface elevation.
Does the water level affect water quality at Somerville Lake Big Creek Arm?
Somerville Lake Big Creek Arm has nutrient and algae readings on record from state and federal monitoring. Each lake's nutrient and algae readings — total phosphorus, total nitrogen, chlorophyll-a, and turbidity — are shown beside the EPA National Lakes Assessment 2022 condition class for that lake's own ecoregion, so a reading is compared against the lakes it would naturally resemble. LakeQuality publishes no letter grade. 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 readings 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 08109900, a public feed with no licence restriction. The water-quality readings come from EPA Water Quality Portal samples submitted by Texas Commission on Environmental Quality. For advisories and standards in Texas, TCEQ is the authority — a gauge reading is neither.