Missouri reservoir · state assessment record
Monroe City Lake
Assessment decisions reported by Missouri to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle.
- 94
- Assessed acres
- Reservoir
- Water type
- 668.4 ft
- Water Surface Elevation (provisional)
This waterbody in one line
Monroe City Lake, a reservoir in Missouri, 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 above the national median by assessed acreage (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. Missouri assesses human health protection as not supported; it reported no verdict on fish consumption itself. A USGS gauge tracks its water surface elevation daily.
- Not Supporting
- overall status
- P69
- 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.
How Monroe City Lake 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: in-state cause rank
Inside Missouri, cause-list rank is the local separator: Monroe City Lake is 19 of 170 indexed units by listed-cause count, toward the top of that state's filed lists.
Every filed use falls short
On the uses this filer ruled on, fish consumption, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Monroe City Lake: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Monroe City Lake. 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 Monroe City Lake 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, Missouri carries 623 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Monroe City Lake without modification. See our methodology for reporting-unit limits and gauge linking rules.
The record
Assessment entries
Fully Supporting and Not Supporting are the state's definitive verdicts; other entries mean the use was not conclusively assessed in this cycle.
| Assessment entry | Group | Verdict |
|---|---|---|
| Drinking Water Supply | Drinking-water supply designation | Fully Supporting |
| Human Health Protection | Fish-consumption or fishery | Not Supporting |
| Warm Water Habitat | Aquatic-life or related | Not Supporting |
| Irrigation | Other | Insufficient Information |
| Livestock and Wildlife Protection | Aquatic-life or related | Insufficient Information |
| Secondary Contact Recreation | Recreation | Insufficient Information |
| Unclassified with General Criteria Protections | Other | Insufficient Information |
| Whole Body Contact Recreation - Category a | Recreation | Insufficient Information |
Not every entry above is a designated use: Unclassified with General Criteria Protections is a record that the water carries no classified designated use. The state files it in the ATTAINS use column, so it carries whatever verdict the state recorded against it.
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 |
|---|---|---|---|
| Mercury in Fish Tissue | Human Health Protection | 2014 | TMDL priority: Medium |
| Chlorophyll-a | Warm Water Habitat | 2020 | TMDL priority: Medium |
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 in Fish Tissue
- Atmospheric Deposition - Toxics (suspected)
- Chlorophyll-a
- Non-Point Source (suspected)
Reading the record
Where Monroe City Lake sits among peers
70% of Missouri's lakes assessed this deeply also came out mixed
Missouri ruled definitively on 3 designated uses at Monroe City Lake and found 2 of 3 not supported. The dataset shows 23 Missouri lakes judged to that same depth.
Missouri's assessed lakes are most often judged on 1 use; 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 | 89 | 18 | 7 | 3 | 1 |
| Mixed | Not possible | 36 | 16 (this record) | 10 | 3 |
| None supported | 75 | 11 | 0 | 0 | 0 |
Ringed cell: Monroe City Lake. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
Monroe City Lake is one of 623 lake-type waterbodies reported to EPA from Missouri, and one of 170 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 94 assessed acres it ranks 12,179th 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 12,178 lakes with a larger one.
Water level
A USGS gauge tracks this reservoir's water surface elevation daily, and the latest reading is 0.57 ft below the reading 30 days earlier, against a 365-day observed range of 4.0 ft. The state has not yet filed a definitive recreation verdict for this record; that field populates when it reports it in a future Integrated Report cycle.
Water level: 365-day record
Daily water surface elevation values, feet above the North American Vertical Datum of 1988 (NAVD 88), from USGS gauge 05507820 (Monroe City Lake Near Monroe City, Mo), shown weekly. Readings are daily-batch snapshots, not real-time conditions. Each daily value is a single reading taken at 08:00, not a daily mean. It is the only daily statistic USGS files for this gauge.
- Latest reading
- 668.4 ft 0.57000000000005ft vs 30 days earlier
- 2026-08-16 · Provisional, subject to USGS revision
Water level: 365-day record
Subscribe to water level updates for Monroe City Lake (RSS)
68 of the 366 daily values in this window (19%) are provisional and subject to USGS revision; USGS has approved this gauge's record through 2026-06-09.
Full gauge record: USGS monitoring location 05507820
In context
Where Monroe City 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
94 Top 31% larger than 69% 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 Monroe City Lake. Hover or tap any bar for its full count and share.
In context
Missouri context
ATTAINS carries 623 lake-type waterbodies in Missouri, 151 assessed as not supporting at least one use and 118 fully supporting. Among the 170 indexed units there, Monroe City Lake ranks 19th by listed-cause count (2 listed causes) and 67th by assessed size among the 170 with an area filed; it sits in the not-supporting set (151 statewide) . Its listed causes include Mercury in Fish Tissue and Chlorophyll-a, which also appear among Missouri's most-filed impairment causes (led by Chlorophyll-a).
| Other large assessed lakes in Missouri | Assessed acres |
|---|---|
| Lake of the Ozarks Not Supporting | 59,520 |
| Harry S Truman Reservoir Not Supporting | 55,600 |
| Table Rock Lake Not Supporting | 41,747 |
| Stockton Lake Fully Supporting | 23,680 |
| Mark Twain Lake Not Supporting | 20,100 |
| Bull Shoals Lake Not Supporting | 9,000 |
Peers near Monroe City Lake's size or cause load
Similar assessed acres
Nearest filed extents (94 acres here).
- Ashley Lake · 94 acres · MA
- Barton Lake · 94 acres · IN
- Grama Lake · 94 acres · OK
- Heart Pond · 94 acres · MA
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
- The listing here is on a fishery use, not on fish consumption, and this state reported no consumption verdict for this reservoir. Your state fish-advisory program is the source for whether the catch is safe to eat. Consumption status guide
- Water levels shown are daily snapshots. Seasonal drawdown and datum conventions matter when comparing levels. How to read level data
- 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 MO_7031.00. 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.