Washington reservoir · state assessment record
Pipe Lake
Assessment decisions reported by Washington to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2022 reporting cycle.
- 52
- Assessed acres
- Lake / Reservoir / Pond
- Water type
This waterbody in one line
Pipe Lake, a reservoir in Washington, is assessed as not supporting one or more designated uses, with one listed impairment cause in the state's most recent Integrated Report cycle (2022). By assessed acreage it sits above the national median by assessed acreage (38,628 lakes); its impairment list is among the longest nationally (one listed cause vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.
- Not Supporting
- overall status
- P56
- Assessed size nationally
- P20
- Shorter cause list
- Not Supporting
- aquatic life
Assessment verdicts are the state agency's decisions as reported to EPA ATTAINS; PlainLakes renders them without modification.
A composite of this record's EPA ATTAINS designated-use verdicts, filed impairment count, and assessment currency, weighted and benchmarked against the national corpus of assessed active waterbodies. This is a water-quality standing, not a human-recreation or property-value judgment, and dimensions with no filed verdict drop out rather than count against the score.
Where Pipe Lake stands in 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: in-state cause rank
Inside Washington, cause-list rank 268 of 385 is mid-pack, the state peer table is not driven by an extreme list length here.
No ruled-on use clears the bar
On the uses this filer ruled on, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Pipe Lake: Category 4C reading
Category 4C marks impairment from pollution that is not a pollutant (for example habitat or flow alteration) on Pipe Lake. A classic TMDL load model often does not apply; the cause list should name the non-pollutant stressor.
Overall status: not supporting
The filer's overall status for Pipe Lake is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
Mid-pack inside Washington
Size rank 235 of 385 inside Washington is mid-pack; the national percentile is the better scale comparison for this unit.
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 Pipe 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 |
|---|---|---|
| Aquatic Life - General | Aquatic-life or related | Not Supporting |
| Aquatic Life - Toxics | Aquatic-life or related | Insufficient Information |
| Recreation - Primary Contact | Recreation | Insufficient Information |
| Water Supply - Domestic Water | Drinking-water supply designation | Insufficient Information |
The record
Listed impairment causes
Causes the state listed as impairing designated uses of this reservoir, with the cycle each was first listed. None is a pollutant, so none carries a TMDL cleanup plan.
| Cause | Affected uses | First listed | Cleanup standing |
|---|---|---|---|
| Non-Native Aquatic Plants | Aquatic Life - General | 2004 | Not applicable (non-pollutant) |
Reading the record
Pipe Lake: Category 4C reading
4C Category 4C: impaired by a non-pollutant; TMDL programme does not apply
Washington filed this assessment unit as Category 4C: the impairment is not caused by a pollutant, so the Clean Water Act 303(d) cleanup-plan (TMDL) programme, which allocates pollutant loads, does not apply here.
A 4C listing is still an impairment finding about designated uses; it is not a clean bill of health. How listing and cleanup work.
Scale and rank
Pipe Lake is one of 832 lake-type waterbodies reported to EPA from Washington, and one of 385 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 52 assessed acres it ranks 17,109th 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 17,108 lakes with a larger one.
Still unfiled
The state has not yet filed a definitive fish-consumption verdict and a definitive recreation verdict for this record; those fields populate when it reports them in a future Integrated Report cycle.
Why no water-level record
Pipe Lake has no daily USGS water-level or reservoir-storage series on this page because NWIS lists a lake monitoring site named for the waterbody, but the site is not active, and PlainLakes ingests only the active inventory, so there is no series to attach. How PlainLakes links gauges.
In context
Where Pipe 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
52 Top 44% larger than 56% 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
Listed causes vs waterbodies carrying a verdict
How many impairment causes U.S. waterbodies with a reported verdict carry
1 Longer than most more listed causes than 49% of 23,610 waterbodies carrying a verdict
named waterbodies carrying a verdict, 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 Pipe 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. Among the 385 indexed units there, Pipe Lake ranks 268th by listed-cause count (one listed cause) and 235th by assessed size among the 385 with an area filed; it sits in the not-supporting set (393 statewide) . Its listed causes include Non-Native Aquatic Plants, which also appears among Washington's most-filed impairment causes (led by Non-Native Aquatic Plants).
| 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 |
Peers near Pipe Lake's size or cause load
Similar assessed acres
Nearest filed extents (52 acres here).
- Long Pond · 52 acres · FL
- Gander Lake · 52 acres · WI
- Buffalo Creek Reservoir · 52 acres · WV
- Chaska · 52 acres · MN
Similar cause load
Nearest listed-cause counts (1 here). Peers already in the acreage column are omitted.
- Aaron · 1 causes · MN
- Aaron River Reservoir · 1 causes · MA
- Abbotts Creek (including Lexington-Thomasville Water Supply Reservoir at normal reservoir elevation, Tom-A-Lex Lake) · 1 causes · NC
- Abeniki Lake · 1 causes · NH
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
- 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 WA17110013000391_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.