Louisiana lake · state assessment record
Bayou Desiard and Lake Bartholomew; also called Dead Bayou
Assessment decisions reported by Louisiana to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle.
- 1,840
- Assessed acres
- Lake, Freshwater
- Water type
This waterbody in one line
Bayou Desiard and Lake Bartholomew; also called Dead Bayou, a lake in Louisiana, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2026). By assessed acreage it sits among the largest 5% by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (2 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.
- Not Supporting
- overall status
- P96
- Assessed size nationally
- P10
- 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.
Bayou Desiard and Lake Bartholomew; also called Dead Bayou against the ATTAINS 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 Bayou Desiard and Lake Bartholomew; also called Dead Bayou nationally is assessed size: 1,840 acres, larger than 96% of the 38,628 lake-type units with an area on file.
Every ruled-on use is not supporting
On the uses this filer ruled on, recreation, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Bayou Desiard and Lake Bartholomew; also called Dead Bayou: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Bayou Desiard and Lake Bartholomew; also called Dead Bayou. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
Longer than most cause lists
2 listed causes puts this unit above 80% of assessed lake-type records by list length. Treat that as a coding-and-sampling signal: states that split pollutants finely mint longer lists without proving worse water.
Overall status: not supporting
The filer's overall status for Bayou Desiard and Lake Bartholomew; also called Dead Bayou 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, Louisiana carries 76 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Bayou Desiard and Lake Bartholomew; also called Dead Bayou 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. The latest monitoring Louisiana filed against this record runs through 2023. For the definitive verdicts on this record, Louisiana filed the assessment basis as Monitored Data. Those are EPA's own words, not PlainLakes' summary of them. Louisiana filed its own confidence on the 4 definitive verdicts it rated: Fair and 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 |
|---|---|---|
| Drinking Water Supply | Drinking-water supply designation | Fully Supporting Filer confidence: Fair |
| Fish and Wildlife Propagation | Aquatic-life or related | Not Supporting Filer confidence: Fair on physical/chemical; Good on toxicological |
| Primary Contact Recreation | Recreation | Not Supporting Filer confidence: Fair |
| Secondary Contact Recreation | Recreation | Fully Supporting Filer confidence: Fair |
The record
Listed impairment causes
Causes the state listed as impairing designated uses of this lake, with the cycle each was first listed and the Clean Water Act action recorded against it.
| Cause | Affected uses | First listed | Cleanup standing |
|---|---|---|---|
| Mercury - Fish Consumption Advisory | Fish and Wildlife Propagation | 2000 | TMDL priority: Low |
| Fecal Coliform | Primary Contact Recreation | 2012 | 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.
- Mercury - Fish Consumption Advisory
- Atmospheric Deposition - Toxics (suspected)
- Fecal Coliform
- On-Site Treatment Systems (Septic Systems and Similar Decentralized Systems) (suspected)
Louisiana also recorded the source of at least one listing here as unknown, including for Mercury - Fish Consumption Advisory.
Reading the record
Where Bayou Desiard and Lake Bartholomew; also called Dead Bayou sits among peers
11 of 13 Louisiana lakes assessed this deeply also came out mixed
Louisiana ruled definitively on 4 designated uses at Bayou Desiard and Lake Bartholomew; also called Dead Bayou and found 2 of 4 not supported. The dataset shows 13 Louisiana lakes judged to that same depth.
Louisiana's assessed lakes are most often judged on 3 uses; this one was judged on 4.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 1 | 0 | 8 | 2 | 0 |
| Mixed | Not possible | 4 | 31 | 11 (this record) | 6 |
| None supported | 12 | 0 | 0 | 0 | 0 |
Ringed cell: Bayou Desiard and Lake Bartholomew; also called Dead Bayou. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Bayou Desiard and Lake Bartholomew; also called Dead Bayou is one of 76 lake-type waterbodies reported to EPA from Louisiana, and one of 74 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 1,840 assessed acres it ranks 1,458th 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 1,457 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.
Reported trophic class
Louisiana 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 Bayou Desiard and Lake Bartholomew; also called Dead Bayou 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
1,840 Top 4% larger than 96% 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
2 Longer than most more listed causes than 80% 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 Bayou Desiard and Lake Bartholomew; also called Dead Bayou. Hover or tap any bar for its full count and share.
In context
Louisiana context
ATTAINS carries 76 lake-type waterbodies in Louisiana, 64 assessed as not supporting at least one use and 11 fully supporting. Among the 74 indexed units there, Bayou Desiard and Lake Bartholomew; also called Dead Bayou ranks 21st by listed-cause count (2 listed causes) and 37th by assessed size among the 74 with an area filed; it sits in the not-supporting set (64 statewide) . Its listed causes include Mercury - Fish Consumption Advisory, which also appears among Louisiana's most-filed impairment causes (led by Mercury - Fish Consumption Advisory). It also lists Fecal Coliform, outside that top-five list.
| Other large assessed lakes in Louisiana | Assessed acres |
|---|---|
| Toledo Bend Reservoir-From Texas-Louisiana state line to Toledo Bend Dam Not Supporting | 165,487 |
| White Lake Not Supporting | 56,487 |
| Lake Salvador Not Supporting | 49,477 |
| Grand Lake Not Supporting | 47,869 |
| Lac Des Allemands Not Supporting | 16,596 |
| Catahoula Lake Not Supporting | 16,509 |
Peers near Bayou Desiard and Lake Bartholomew; also called Dead Bayou's size or cause load
Similar assessed acres
Nearest filed extents (1,840 acres here).
- Lake Coleman · 1,842 acres · TX
- Sherman Lake (in Delta Waterways, western portion) · 1,842 acres · CA
- Beulah Reservoir · 1,843 acres · OR
- Grenada Lake · 1,836 acres · MS
Similar cause load
Nearest listed-cause counts (2 here). Peers already in the acreage column are omitted.
- 12th St. Beach · 2 causes · IL
- 31st St. Beach · 2 causes · IL
- 49th St. Beach · 2 causes · IL
- 57th St. Beach · 2 causes · IL
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 LA080701_00. 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.