Water elevation · USGS gauge 07130000 · updated August 29, 2026
Water elevation
3801.43ft
feet above sea level
Gauge 07130000, John Martin Reservoir at Caddoa, CO, 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 John Martin Reservoir at Caddoa, CO. 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
- 3801.43 ft · August 29, 2026
- Water quality
- Readings on the lake page
The Corps of Engineers reads John Martin Dam at 3,801.38 ft, 50.46 ft below its Top of Conservation of 3,851.84 ft.
Both numbers come from the U.S. Army Corps of Engineers for its John Martin Dam 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 John Martin Reservoir
John Martin Reservoir has limited nutrient and algae sampling on record. A lake without recent nutrient or algae sampling shows whatever measurements exist rather than an estimate.
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.
Common questions
What is the water level at John Martin Reservoir right now?
The most recent reading from the USGS gauge at John Martin Reservoir at Caddoa, CO is a water elevation of 3801.43 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 John Martin Reservoir at Caddoa, CO. 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 John Martin Reservoir low?
John Martin Reservoir stood at 3,801.38 ft on September 27, 2026, 50.46 ft below its Top of Conservation of 3,851.84 ft. Both numbers come from the U.S. Army Corps of Engineers for its John Martin Dam 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 John Martin Reservoir?
John Martin Reservoir has limited nutrient and algae sampling on record. 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 07130000, a public feed with no licence restriction. The water-quality readings come from EPA Water Quality Portal samples submitted by Colorado Dept. of Public Health & Environment-WQCD. For advisories and standards in Colorado, CDPHE is the authority — a gauge reading is neither.