Oklahoma lake · tribal assessment record
Lake Nahni Waiya Site 2
Assessment decisions reported by The Choctaw Nation of Oklahoma to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2022 reporting cycle.
- 104
- Assessed acres
- Lake
- Water type
This waterbody in one line
Lake Nahni Waiya Site 2, a lake in Oklahoma, is assessed as fully supporting its designated uses, with no impairment causes listed in the Choctaw Nation of Oklahoma'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 shorter than on half of assessed lakes (0 listed causes).
- Fully Supporting
- overall status
- P71
- Assessed size nationally
- P51
- Shorter cause list
Assessment verdicts are the Choctaw Nation of Oklahoma'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.
How Lake Nahni Waiya Site 2 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: cause-list length
The standout filed fact is a short cause list: 0 causes, shorter than 51% of assessed lake-type units. A short list can mean a focused impairment, or a shallow assessment.
All ruled-on uses pass
The filed use determinations for recreation are all Fully Supporting. Where an overall IR category still flags the unit, look at the cause list and report standing rather than treating the use row as empty.
Overall status: fully supporting
Overall status is Fully Supporting. If an IR category or cause row still appears, it usually reflects a prior listing path or a use the overall rollup does not collapse, read those sections rather than stopping at the tile.
Large assessed unit
At 104 acres, Lake Nahni Waiya Site 2 clears the upper tercile of assessed lake-type units with an area on file (11,413 still larger). Size comparisons use the portal's deduplicated lake ranking population, not raw ATTAINS row counts.
According to the U.S. Environmental Protection Agency's ATTAINS program, Oklahoma carries 456 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Lake Nahni Waiya Site 2 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 Choctaw Nation of Oklahoma's definitive verdicts; other entries mean the use was not conclusively assessed in this cycle. The latest monitoring the Choctaw Nation of Oklahoma filed against this record runs through 2023. For the one definitive verdict on this record, the Choctaw Nation of Oklahoma filed the assessment basis as Monitored Data. Those are EPA's own words, not PlainLakes' summary of them.
| Designated use | Group | Verdict |
|---|---|---|
| Primary Body Contact Recreation | Recreation | Fully Supporting |
| General | Other | Insufficient Information |
| Warm Water Aquatic Community | Aquatic-life or related | Insufficient Information |
The record
Listed impairment causes
The Choctaw Nation of Oklahoma's reported assessment lists no impairment causes for this lake.
Reading the record
Where Lake Nahni Waiya Site 2 sits among peers
50% of Oklahoma's lakes assessed this deeply were also judged fully supported
The Choctaw Nation of Oklahoma ruled definitively on a single designated use at Lake Nahni Waiya Site 2 and found it supported. The dataset shows 26 Oklahoma lakes judged to that same depth.
Oklahoma's assessed lakes are most often judged on 5 or more uses; this one was judged on 1.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 13 (this record) | 8 | 7 | 8 | 9 |
| Mixed | Not possible | 6 | 12 | 30 | 92 |
| None supported | 13 | 0 | 0 | 0 | 0 |
Ringed cell: Lake Nahni Waiya Site 2. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Lake Nahni Waiya Site 2 is one of 456 lake-type waterbodies reported to EPA from Oklahoma. It is not among the 173 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 104 assessed acres it ranks 11,414th 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 11,413 lakes with a larger one.
What this record holds
The Choctaw Nation of Oklahoma completed an assessment here and listed no impairment cause, so the record holds a verdict and its supporting use rows but no pollutant to track over time. The Choctaw Nation of Oklahoma has not yet filed a definitive fish-consumption verdict and a definitive aquatic-life verdict for this record; those fields populate when it reports them in a future Integrated Report cycle.
Reported trophic class
The Choctaw Nation of Oklahoma carried the trophic field for this assessment unit and filed it as unclassified, which records that no class was determined rather than that the water is unenriched. What the trophic scale measures.
In context
Where Lake Nahni Waiya Site 2 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
104 Top 29% larger than 71% 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
0 Among the shortest cause lists fewer listed causes than 51% 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 Lake Nahni Waiya Site 2. Hover or tap any bar for its full count and share.
In context
Oklahoma context
ATTAINS carries 456 lake-type waterbodies in Oklahoma, 153 assessed as not supporting at least one use and 45 fully supporting.
| Other large assessed lakes in Oklahoma | Assessed acres |
|---|---|
| Grand Lake Site 12 Not Supporting | 46,500 |
| Grand Lake Site 13 Not Supporting | 46,500 |
| Grand Lake Site 14 Fully Supporting | 46,500 |
| Grand Lake Site 15 Fully Supporting | 46,500 |
| Robert S. Kerr Lake Not Supporting | 43,380 |
| Texoma Lake, Red River Arm, Lower Not Supporting | 31,081 |
Peers near Lake Nahni Waiya Site 2's size or cause load
Similar assessed acres
Nearest filed extents (104 acres here).
- Echo (Plymth) · 104 acres · VT
- Edna · 104 acres · MN
- Gull Pond · 104 acres · MA
- Hy-Crest Pond · 104 acres · MA
Similar cause load
Nearest listed-cause counts (0 here). Peers already in the acreage column are omitted.
- 31st Street Harbor · 0 causes · IL
- 42nd Avenue East Beach · 0 causes · MN
- 59th Street Harbor · 0 causes · IL
- 657 Dunleavy (Beach) · 0 causes · MI
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 Choctaw Nation of Oklahoma's reported decisions for assessment unit LNW-002. 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.