Some of these decisions are EPA's. 1 of these 623 records carries a Clean Water Act cleanup plan EPA established rather than Missouri. They are counted in every figure on this page, and each record page names which.
State water-quality picture · #14 by reported lake-type waterbodies
Missouri lakes and reservoirs
Every figure on this page is computed from the assessment decisions Missouri reported to the U.S. Environmental Protection Agency under Clean Water Act sections 303(d) and 305(b) (reporting cycles 2026), plus daily water-level observations from the U.S. Geological Survey.
- 623
- Reported waterbodies
- 151
- Not supporting a use
- 49
- Fish use not supporting
- 5
- Gauged lakes
Missouri in one line
623 lake-type waterbodies in Missouri are reported to EPA ATTAINS across reporting cycles 2026: 151 assessed as not supporting at least one designated use, 118 fully supporting, and 354 without a definitive overall verdict. The most-listed impairment cause is Chlorophyll-a, on 104 waterbodies.
- 623
- reported waterbodies
- 151
- not supporting a use
- 118
- fully supporting
- 57%
- of definitive verdicts impaired
An unassessed waterbody is neither confirmed clean nor confirmed impaired; states assess on multi-year cycles. 2 of those 118 fully supporting verdicts rest on designated uses this site does not report (irrigation, navigation and industrial water supply), with Missouri recording no verdict on fish consumption, recreation, aquatic life and drinking water. They are counted above because the state filed them, and excluded from the impaired share below because that figure compares states.
Missouri pairs a mid-pack inventory with a denser USGS gauge link-set
5 gauge-linked lakes put Missouri in the upper third of states on that link count, against a mid-third register of 623 units.
Data updated 2026-08-17
According to the U.S. Environmental Protection Agency's ATTAINS program, Missouri reported 623 lake-type waterbodies in Missouri in the August 2026 extract. See our methodology for filer attribution and multi-year reporting cycles.
How Missouri's large inventory splits across overall status
Each of the 623 lake-type units reported by Missouri lands in exactly one overall-status bucket. On a register this large, the bar is an inventory partition, the cause chart and national gauge below answer different questions.
Most-listed impairment causes in Missouri
Waterbodies carrying each listed cause, most first
- Chlorophyll-a
Chlorophyll-a
104 waterbodies
- Mercury in Fish Tissue
Mercury in Fish Tissue
50 waterbodies
- Nitrogen, Total 13
Nitrogen, Total
13 waterbodies
- Phosphorus, Total 9
Phosphorus, Total
9 waterbodies
- pH 4
pH
4 waterbodies
What this shows Chlorophyll-a is the most-listed impairment cause in Missouri, on 104 of the lake-type waterbodies reported there.
Computed share from EPA ATTAINS filed records, not an official EPA rating or safety grade.
Missouri: 57% of ruled verdicts are not-supporting, against a national share of 53%, 1.1× the national rate.
Reporting practice
Where Missouri stands on definitive-verdict coverage
Each reporting authority decides how much of the water it files to EPA it actually assesses in a cycle. That decision sets the denominator behind every count on this page.
Missouri holds the 14th-largest reported lake-type inventory in the country, 623 assessment units, carrying a definitive verdict on 42.9% of it. The counts above describe the 267 units carrying a verdict, not all 623 reported. Missouri has also retired 24 lake-type assessment units, superseded filings that are kept on the site but not counted here.
The states reporting at the nearest rates are Oklahoma (42.8%) and Washington (47.2%).
Assessing more of an inventory is a reporting choice, set by cycle length, monitoring budget and how finely a state splits its waters into units. It is not a measure of water quality, and it is why a raw count from one state does not sit beside a raw count from another. How assessment coverage varies.
Missouri against every comparable state
Share of reported lake-type waterbodies carrying a definitive verdict
42.9% 36th of 47 higher than 11 of 47 states
the 47 comparable states, by definitive-verdict share
Each bar is a band; taller bars hold more states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA ATTAINS · Reporting cycles 1987–2026
Each bar counts states whose definitive-verdict share falls in that 10-point band. The 47 states shown are those reporting at least 25 lake-type units; a share off a smaller inventory is precision the data does not have.
By size
Largest assessed lakes in Missouri
By assessed acreage as reported in ATTAINS. Acreage is the assessed unit's size, which can differ from a lake's full surface area.
| # | Waterbody | Assessed acres |
|---|---|---|
| 1 | Lake of the Ozarks Not Supporting | 59,520 |
| 2 | Harry S Truman Reservoir Not Supporting | 55,600 |
| 3 | Table Rock Lake Not Supporting | 41,747 |
| 4 | Stockton Lake Fully Supporting | 23,680 |
| 5 | Mark Twain Lake Not Supporting | 20,100 |
| 6 | Bull Shoals Lake Not Supporting | 9,000 |
| 7 | Lake Wappapello Not Supporting | 7,827 |
| 8 | Smithville Lake Not Supporting | 7,738 |
| 9 | Pomme de Terre Lake Not Supporting | 7,675 |
| 10 | Thomas Hill Reservoir Not Supporting | 4,400 |
| 11 | Long Branch Lake Fully Supporting | 2,686 |
| 12 | Silver Lake-Levee 3 Not Assessed | 2,464 |
By cause count
Most-listed waterbodies in Missouri
Waterbodies carrying the most listed impairment causes among the lake-type units reported by Missouri.
| # | Waterbody | Listed causes |
|---|---|---|
| 1 | Weatherby Lake Not Supporting | 4 |
| 2 | Clearwater Lake Not Supporting | 3 |
| 2 | Deer Ridge Community Lake Not Supporting | 3 |
| 2 | Fox Valley Lake Not Supporting | 3 |
| 2 | Lower Taum Sauk Lake Not Supporting | 3 |
| 2 | Old Lake Not Supporting | 3 |
| 7 | Belleview Lake Not Supporting | 2 |
| 7 | Buffalo Bill Lake Not Supporting | 2 |
| 7 | Coot Lake Not Supporting | 2 |
| 7 | Crane Lake Not Supporting | 2 |
9 of the 10 rows in this table tie on the ranked value: 5 at 3 (rank 2), 4 at 2 (rank 7). Tied rows share a rank and are listed in no meaningful order; where a tie reaches the top the medal is shared, because nothing separates those rows.
Gauge network
Lakes with a daily level record in Missouri
Lakes with a linked USGS gauge and a daily water-level record. Readings are daily-batch snapshots, not real-time.
- Stockton Lake Fully Supporting USGS gauge 06918990 Level record →
- Pomme de Terre Lake Not Supporting USGS gauge 06921325 Level record →
- Lake Taneycomo Not Supporting USGS gauge 07053600 Level record →
- Clearwater Lake Not Supporting USGS gauge 07062000 Level record →
- Monroe City Lake Not Supporting USGS gauge 05507820 Level record →
States with similar inventory scale or impairment load
Two EPA ATTAINS peer sets outside Missouri. The reporting-practice chart above stays on definitive-verdict share; these neighborhoods are cross-state nearest neighbors on register size and not-supporting counts.
States with a similar reported inventory
Nearest states by lake-type units on the register (623 here).
- Idaho · 630 units · 7 off
- New Jersey · 611 units · 12 off
- South Carolina · 611 units · 12 off
- California · 607 units · 16 off
States with a similar not-supporting load
Nearest states by units assessed not supporting a use (151 here). Inventory peers above are omitted.
- Oklahoma · 153 not supporting · 2 off
- Vermont · 154 not supporting · 3 off
- Indiana · 145 not supporting · 6 off
- South Dakota · 145 not supporting · 6 off
Peers are nearest-neighbor matches on EPA ATTAINS register size and not-supporting counts among states with at least 25 reported units. Impairment peers skip states already listed in the inventory column so the two link sets stay distinct.
Using this state picture
- Comparisons across states hold on shares, not counts: 42.9% of the inventory reported from Missouri carries a definitive verdict, 36th of 47 comparable states. National rankings
- Fish-consumption verdicts here are assessment decisions. Species-level meal advice comes from the state fish-advisory program. Consumption guide
- Browse every named Missouri waterbody with a populated record. Browse waterbodies
PlainLakes renders state assessment decisions and federal gauge observations without modification.
Figures on this page are computed from the assessment decisions Missouri reported to EPA's ATTAINS system and from USGS National Water Information System daily values, no number is typed in by an editor. State counts aggregate every lake-type assessment unit reported by Missouri, including unnamed units that never receive their own page. 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.