Missouri reservoir · state assessment record
City Lake Harrisonville
Assessment decisions reported by Missouri to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle.
- 28
- Assessed acres
- Reservoir
- Water type
This waterbody in one line
City Lake Harrisonville, a reservoir in Missouri, is assessed as not supporting one or more designated uses, with one listed impairment cause in the state's most recent Integrated Report cycle (2026). By assessed acreage it sits below the national median by assessed acreage (38,628 lakes); its impairment list is among the longest nationally (one listed cause vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.
- Not Supporting
- overall status
- P41
- Assessed size nationally
- P20
- 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.
Where City Lake Harrisonville 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 Missouri, cause-list rank 104 of 170 is mid-pack, the state peer table is not driven by an extreme list length here.
No ruled-on use clears the bar
On the uses this filer ruled on, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
City Lake Harrisonville: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for City Lake Harrisonville. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
Overall status: not supporting
The filer's overall status for City Lake Harrisonville is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
Mid-pack inside Missouri
Size rank 119 of 170 inside Missouri is mid-pack; the national percentile is the better scale comparison for this unit.
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 City Lake Harrisonville 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 |
|---|---|---|
| Warm Water Habitat | Aquatic-life or related | Not Supporting |
| Drinking Water Supply | Drinking-water supply designation | Insufficient Information |
| Human Health Protection | Fish-consumption or fishery | Insufficient Information |
| 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 B | 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 |
|---|---|---|---|
| Chlorophyll-a | Warm Water Habitat | 2022 | 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.
- Chlorophyll-a
- Non-Point Source (suspected)
Reading the record
Where City Lake Harrisonville sits among peers
46% of Missouri's lakes assessed this deeply also had no use supported
Missouri ruled definitively on a single designated use at City Lake Harrisonville and found it not supported. The dataset shows 164 Missouri lakes judged to that same depth.
Missouri's assessed lakes are most often judged on 1 use, as this one was.
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 | 10 | 3 |
| None supported | 75 (this record) | 11 | 0 | 0 | 0 |
Ringed cell: City Lake Harrisonville. Source: EPA ATTAINS, Reporting cycles 1987–2026.
Scale and rank
City Lake Harrisonville 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 28 assessed acres it ranks 22,978th 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 22,977 lakes with a larger one.
Still unfiled
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 City Lake Harrisonville 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
28 Top 59% larger than 41% 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
1 Longer than most more listed causes than 49% 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 City Lake Harrisonville. 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, City Lake Harrisonville ranks 104th by listed-cause count (one listed cause) and 119th by assessed size among the 170 with an area filed; it sits in the not-supporting set (151 statewide) . Its listed causes include Chlorophyll-a, which also appears 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 City Lake Harrisonville's size or cause load
Similar assessed acres
Nearest filed extents (28 acres here).
- Austin · 28 acres · VT
- Bents Pond · 28 acres · MA
- Cranberry Pond · 28 acres · MA
- Culbertson Lake · 28 acres · WI
Similar cause load
Nearest listed-cause counts (1 here). Peers already in the acreage column are omitted.
- Aaron · 1 causes · MN
- Aaron River Reservoir · 1 causes · MA
- Abbotts Creek (including Lexington-Thomasville Water Supply Reservoir at normal reservoir elevation, Tom-A-Lex Lake) · 1 causes · NC
- Abeniki Lake · 1 causes · NH
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 MO_7217.00. 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.