Tennessee reservoir · state assessment record
Emory River Embayment of Watts Bar Reservoir (363 acres)
Assessment decisions reported by Tennessee to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle.
- 363
- Assessed acres
- Lake / Reservoir / Pond
- Water type
This waterbody in one line
Emory River Embayment of Watts Bar Reservoir, a reservoir in Tennessee, is assessed as not supporting one or more designated uses, with 3 listed impairment causes in the state's most recent Integrated Report cycle (2026). By assessed acreage it sits in the upper quartile by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (3 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as fully supporting.
- Not Supporting
- overall status
- P88
- Assessed size nationally
- P5
- Shorter cause list
- Fully 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.
Reading Emory River Embayment of Watts Bar Reservoir's filed record
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 cause-list length: 3 listed impairment causes, a longer list than 90% of assessed lake-type units (n=23,610). List length tracks how states sample and code, not a severity score.
A split ruling across uses
This record splits: Not Supporting on recreation, Fully Supporting on aquatic life. The divergence is inside the designated-use matrix, not a single all-or-nothing label.
Emory River Embayment of Watts Bar Reservoir: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Emory River Embayment of Watts Bar Reservoir. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
Large assessed unit
At 362.6 acres, Emory River Embayment of Watts Bar Reservoir clears the upper tercile of assessed lake-type units with an area on file (4,668 still larger). Size comparisons use the portal's deduplicated lake ranking population, not raw ATTAINS row counts.
Overall status: not supporting
The filer's overall status for Emory River Embayment of Watts Bar Reservoir is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
According to the U.S. Environmental Protection Agency's ATTAINS program, Tennessee carries 117 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Emory River Embayment of Watts Bar Reservoir 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. For the definitive verdicts on this record, Tennessee filed the assessment basis as Extrapolated Data. Those are EPA's own words, not PlainLakes' summary of them; where a verdict is filed as extrapolated, the state did not reach it from monitoring alone. Tennessee filed its own confidence on the 6 definitive verdicts it rated: Good. That rating is the filer's, in EPA's own field, and EPA publishes no definition of the four words it offers.
| Designated use | Group | Verdict |
|---|---|---|
| Domestic Water Supply | Drinking-water supply designation | Fully Supporting Filer confidence: Good |
| Fish and Aquatic Life | Aquatic-life or related | Fully Supporting Filer confidence: Good |
| Industrial Water Supply | Other | Fully Supporting Filer confidence: Good |
| Irrigation | Other | Fully Supporting Filer confidence: Good |
| Livestock Watering and Wildlife | Other | Fully Supporting Filer confidence: Good |
| Recreation | Recreation | Not Supporting Filer confidence: Good |
The record
Listed impairment causes
Causes the state listed as impairing designated uses of this reservoir, with the cycle each was first listed and the Clean Water Act action recorded against it.
| Cause | Affected uses | First listed | Cleanup standing |
|---|---|---|---|
| Chlordane in Fish Tissue | Recreation | 2026 | TMDL priority: Low |
| Mercury in Fish Tissue | Recreation | 2026 | TMDL priority: Low |
| PCBs in Fish Tissue | Recreation | 2026 | TMDL priority: Low |
Probable sources named by the state
Each source below is listed under the cause the state filed it against, and carries the word the state filed with it — confirmed, or suspected.
- Chlordane in Fish Tissue
- Contaminated Sediments (suspected)
- Mercury in Fish Tissue
- Atmospheric Deposition (suspected)
- PCBs in Fish Tissue
- Contaminated Sediments (suspected)
Reading the record
Assessment basis on Emory River Embayment of Watts Bar Reservoir
1 filed assessment basis on this record
For the definitive verdicts on this record, Tennessee filed the assessment basis as Extrapolated Data. Those are EPA's own words, not PlainLakes' summary of them; where a verdict is filed as extrapolated, the state did not reach it from monitoring alone.
The cycle is when the state reported; the monitoring year, where filed, is when it measured. How to read assessment currency.
Scale and rank
Emory River Embayment of Watts Bar Reservoir is one of 117 lake-type waterbodies reported to EPA from Tennessee, and one of 73 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 363 assessed acres it ranks 4,669th 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 4,668 lakes with a larger one.
Not yet on record
The state has not yet filed a definitive fish-consumption verdict for this record; that field populates when it reports it in a future Integrated Report cycle.
In context
Where Emory River Embayment of Watts Bar Reservoir 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
363 Top 12% larger than 88% 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
3 Longer than most more listed causes than 90% 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 Emory River Embayment of Watts Bar Reservoir. Hover or tap any bar for its full count and share.
In context
Tennessee context
ATTAINS carries 117 lake-type waterbodies in Tennessee, 60 assessed as not supporting at least one use and 16 fully supporting. Among the 73 indexed units there, Emory River Embayment of Watts Bar Reservoir ranks 17th by listed-cause count (3 listed causes) and 58th by assessed size among the 73 with an area filed; it sits in the not-supporting set (60 statewide) . Its listed causes include Mercury in Fish Tissue and PCBs in Fish Tissue, which also appear among Tennessee's most-filed impairment causes (led by Mercury in Fish Tissue). It also lists Chlordane in Fish Tissue, outside that top-five list.
| Other large assessed lakes in Tennessee | Assessed acres |
|---|---|
| Kentucky Reservoir Fully Supporting | 99,500 |
| Chickamauga Reservoir Fully Supporting | 35,400 |
| Watts Bar Reservoir Not Supporting | 34,075 |
| Douglas Reservoir Fully Supporting | 30,400 |
| Old Hickory Reservoir Fully Supporting | 27,439 |
| Cherokee Reservoir Not Supporting | 25,964 |
Peers near Emory River Embayment of Watts Bar Reservoir's size or cause load
Similar assessed acres
Nearest filed extents (363 acres here).
- Lake Maggiore · 363 acres · FL
- Curtis · 363 acres · MN
- Elliot · 363 acres · MN
- Beaver Dam Run Res-05010007001406 · 363 acres · PA
Similar cause load
Nearest listed-cause counts (3 here). Peers already in the acreage column are omitted.
- 67th St. Beach · 3 causes · IL
- Abiquiu Reservoir · 3 causes · NM
- Absecon Creek (AC Reserviors) (gage to SB) · 3 causes · NJ
- Absecon Creek (below gage) · 3 causes · NJ
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 TN06010208001_3000. 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.