Texas reservoir · state assessment record
Mackenzie Reservoir
Assessment decisions reported by Texas to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2024 reporting cycle.
- 290
- Assessed acres
- Reservoir
- Water type
This waterbody in one line
Mackenzie Reservoir, a reservoir in Texas, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2024). By assessed acreage it sits in the upper quartile 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 fully supporting.
- Not Supporting
- overall status
- P86
- Assessed size nationally
- P10
- 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.
Where Mackenzie Reservoir 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 Texas, cause-list rank is the local separator: Mackenzie Reservoir is 43 of 323 indexed units by listed-cause count, toward the top of that state's filed lists.
Mackenzie Reservoir: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Mackenzie 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 290.4 acres, Mackenzie Reservoir clears the upper tercile of assessed lake-type units with an area on file (5,489 still larger). Size comparisons use the portal's deduplicated lake ranking population, not raw ATTAINS row counts.
Every filed use clears the bar
The filed use determinations for aquatic life 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.
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.
According to the U.S. Environmental Protection Agency's ATTAINS program, Texas carries 489 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Mackenzie 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.
| Designated use | Group | Verdict |
|---|---|---|
| Aquatic Life Use | Aquatic-life or related | Fully Supporting |
| Domestic Water Supply - Public Water Supply | Drinking-water supply designation | Fully Supporting |
| General Use | Other | Not Supporting |
| Recreation Use | Recreation | 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 and the Clean Water Act action recorded against it.
| Cause | Affected uses | First listed | Cleanup standing |
|---|---|---|---|
| Total Dissolved Solids (TDS) | General Use | 2014 | TMDL priority: Low |
| Sulfate | General Use | 2016 | 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.
- Total Dissolved Solids (TDS)
- Drought-Related Impacts (suspected)
- Sulfate
- Drought-Related Impacts (suspected) Internal Nutrient Recycling (suspected)
Texas also recorded the source of at least one listing here as unknown, including for Sulfate.
Reading the record
Where Mackenzie Reservoir sits among peers
31% of Texas's lakes assessed this deeply also came out mixed
Texas ruled definitively on 3 designated uses at Mackenzie Reservoir and found 1 of 3 not supported. The dataset shows 61 Texas lakes judged to that same depth.
Texas's assessed lakes are most often judged on 4 uses; this one was judged on 3.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
| 1 | 2 | 3 | 4 | 5+ | |
|---|---|---|---|---|---|
| All supported | 7 | 76 | 42 | 149 | 34 |
| Mixed | Not possible | 18 | 19 (this record) | 38 | 33 |
| None supported | 14 | 3 | 0 | 0 | 0 |
Ringed cell: Mackenzie Reservoir. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Mackenzie Reservoir is one of 489 lake-type waterbodies reported to EPA from Texas, and one of 323 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 290 assessed acres it ranks 5,490th 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 5,489 lakes with a larger one.
Awaiting a filing
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.
In context
Where Mackenzie 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
290 Top 14% larger than 86% 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 Mackenzie Reservoir. Hover or tap any bar for its full count and share.
In context
Texas context
ATTAINS carries 489 lake-type waterbodies in Texas, 125 assessed as not supporting at least one use and 331 fully supporting. Among the 323 indexed units there, Mackenzie Reservoir ranks 43rd by listed-cause count (2 listed causes) and 283rd by assessed size among the 323 with an area filed; it sits in the not-supporting set (125 statewide) . Its listed causes (Total Dissolved Solids (TDS) and Sulfate) sit outside Texas's top-five list, which is led by Algae.
| Other large assessed lakes in Texas | Assessed acres |
|---|---|
| Lake Texoma Fully Supporting | 49,400 |
| Toledo Bend Reservoir Not Supporting | 41,046 |
| International Falcon Reservoir Fully Supporting | 36,817 |
| Sam Rayburn Reservoir Not Supporting | 28,238 |
| International Amistad Reservoir Fully Supporting | 21,328 |
| Lake Livingston Not Supporting | 18,238 |
Peers near Mackenzie Reservoir's size or cause load
Similar assessed acres
Nearest filed extents (290 acres here).
- Willow Creek Reservoir. · 290 acres · CO
- Triangle Lake · 290 acres · OR
- Prompton Reservoir-02040103000881 · 290 acres · PA
- Lax · 291 acres · MN
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 TX-0228_01. 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.