Water elevation · USGS gauge 01102505 · updated August 29, 2026
Upper Mystic Lake Water LevelNRNot rated for water quality
The USGS gauge at Upper Mystic Lake, Gate House, at Winchester, MA last recorded a water elevation of 114.15 ft on August 29, 2026. In Middlesex County, Massachusetts, Upper Mystic Lake has no letter grade — no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). 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 Mystic River Watershed Association (Massachusetts); the level above comes from the USGS, which runs the gauge.
Water elevation
114.15ft
feet above sea level
Gauge 01102505, Upper Mystic Lake, Gate House, at Winchester, MA, 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 Upper Mystic Lake, Gate House, at Winchester, MA. 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
- 114.15 ft · August 29, 2026
- Water quality
- NRNot rated
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.
Water quality at Upper Mystic Lake
Upper Mystic Lake has no letter grade. No nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). A lake without enough recent summer sampling is published as Not Rated rather than given a letter the data cannot support. Not Rated is never an F.
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 Upper Mystic Lake right now?
The most recent reading from the USGS gauge at Upper Mystic Lake, Gate House, at Winchester, MA is a water elevation of 114.15 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 Upper Mystic Lake, Gate House, at Winchester, MA. 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 Upper Mystic Lake 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 01102505 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 Upper Mystic Lake?
Upper Mystic Lake has no letter grade — no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). 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 01102505, a public feed with no licence restriction. The water-quality grade is built from EPA Water Quality Portal samples submitted by Mystic River Watershed Association (Massachusetts). For advisories and standards in Massachusetts, MassDEP is the authority — a gauge reading is neither.