Washington reservoir · state assessment record
Wynoochee Lake
The assessment record reported by Washington to EPA under Clean Water Act sections 303(d) and 305(b), filed in the 2022 reporting cycle.
- 990
- Assessed acres
- Lake / Reservoir / Pond
- Water type
- 755.3 ft
- Water Surface Elevation (provisional)
This waterbody in one line
Wynoochee Lake, a reservoir in Washington, was reported but not assessed in the state's most recent Integrated Report cycle (2022). By assessed acreage it sits among the largest 10% by assessed acreage nationally (38,628 lakes). A USGS gauge tracks its water surface elevation daily.
- Not Assessed
- overall status
- P94
- Assessed size nationally
Assessment verdicts are the state agency's decisions as reported to EPA ATTAINS; PlainLakes renders them without modification.
How Wynoochee Lake reads against the filed register
Paragraphs are selected by this unit's percentiles and use matrix: different lakes lead with different dimensions. Figures are ATTAINS / portal register arithmetic, not advice.
The signature stat: assessed size
The number that most separates Wynoochee Lake nationally is assessed size: 990.2 acres, larger than 94% of the 38,628 lake-type units with an area on file.
IR category 3 on Wynoochee Lake
The Integrated Report category filed for Wynoochee Lake is 3. PlainLakes renders EPA's code without remapping it into a consumer grade.
Overall status: Not Assessed
ATTAINS overall status on this unit is “Not Assessed”. PlainLakes does not rewrite that vocabulary into a consumer score.
According to the U.S. Environmental Protection Agency's ATTAINS program, Washington carries 832 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Wynoochee Lake without modification. See our methodology for reporting-unit limits and gauge linking rules.
The record
Designated-use assessments
Fully Supporting and Not Supporting are the state's definitive verdicts; other entries mean the use was not conclusively assessed in this cycle.
| Designated use | Group | Verdict |
|---|---|---|
| Harvesting | Fish-consumption or fishery | Insufficient Information |
The record
Listed impairment causes
The state reported this reservoir in its 2022 Integrated Report cycle but reached no assessment determination, so no causes are listed. The unit is recorded under EPA integrated-reporting Category 3: reviewed, with insufficient information to determine whether it meets water-quality standards. An undetermined waterbody is neither confirmed clean nor confirmed impaired.
Reading the record
What Wynoochee Lake's record holds
Scale and rank
Wynoochee Lake is one of 832 lake-type waterbodies reported to EPA from Washington. It is not among the 385 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 990 assessed acres it ranks 2,282nd by assessed size among the 38,628 lakes the dataset carries an area for, counting a state’s repeated filings of one water once, behind 2,281 lakes with a larger one.
Water level
A USGS gauge tracks this reservoir's water surface elevation daily, and the latest reading is 11.37 ft below the reading 30 days earlier, against a 365-day observed range of 47.0 ft. The state has not yet filed a definitive fish-consumption verdict, a definitive recreation verdict, a definitive aquatic-life verdict, and 1 other for this record; those fields populate when it reports them in a future Integrated Report cycle.
Water level: 365-day record
Daily water surface elevation values, feet above the National Geodetic Vertical Datum of 1929 (NGVD 29), from USGS gauge 12035380 (Wynoochee Lake Near Grisdale, Wa), shown weekly. Readings are daily-batch snapshots, not real-time conditions. Each daily value is a single reading taken at 24:00, not a daily mean. It is the only daily statistic USGS files for this gauge.
- Latest reading
- 755.3 ft 11.370000000000005ft vs 30 days earlier
- 2026-08-15 · Provisional, subject to USGS revision
Water level: 365-day record
Subscribe to water level updates for Wynoochee Lake (RSS)
150 of the 365 daily values in this window (41%) are provisional and subject to USGS revision; USGS has approved this gauge's record through 2026-03-18.
Full gauge record: USGS monitoring location 12035380
In context
Where Wynoochee Lake sits nationally
Assessed size among U.S. lakes
Distribution of assessed acreage across ATTAINS lakes filed with an area, counting a state’s repeated filings of one water once
990 Top 6% larger than 94% of 38,628 lakes
lakes the dataset carries an area for, counting a state’s repeated filings of one water once, bucketed by value
Source EPA ATTAINS · Reporting cycles 1987–2026
In both charts each bar is a band and taller bars hold more waterbodies; the dashed line and filled bar mark Wynoochee Lake. Hover or tap any bar for its full count and share.
In context
Washington context
ATTAINS carries 832 lake-type waterbodies in Washington, 393 assessed as not supporting at least one use and 0 fully supporting.
| Other large assessed lakes in Washington | Assessed acres |
|---|---|
| Bumping Lake Not Assessed | 1,354 |
| Sullivan Lake Not Supporting | 1,298 |
| Deer Lake Not Supporting | 1,146 |
| Loon Lake Not Supporting | 1,094 |
| American Lake Not Supporting | 1,092 |
| Newman Lake Not Supporting | 1,091 |
Lakes near Wynoochee Lake's assessed acres
Similar assessed acres
Nearest filed extents (990 acres here).
- Alger Lake · 991 acres · OR
- Otis Reservoir · 989 acres · MA
- Lake Buchanan · 992 acres · TX
- Mudd Lake · 989 acres · ND
What to do with this record
- Assessment verdicts are cycle-based, not real-time. For fish-consumption decisions, your state advisory program is the binding source. Consumption status guide
- Water levels shown are daily snapshots. Seasonal drawdown and datum conventions matter when comparing levels. How to read level data
- Impairment listings follow the Clean Water Act 303(d) process; a listing is a regulatory finding, not a closure notice. 303(d) explained
PlainLakes renders state assessment decisions and federal gauge observations without modification. It does not issue advisories.
Assessment decisions on this page are rendered directly from state Integrated Report records in EPA's ATTAINS system; gauge figures are daily-value observations from the USGS National Water Information System, no number is typed in by an editor. Overall status, use verdicts, and causes are the state's reported decisions for assessment unit WA17100104000575_001_001. Counts and percentiles are computed across all lake-type records PlainLakes ingests from ATTAINS. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-08-17. Primary sources: EPA ATTAINS and USGS National Water Information System.