Iowa lake · state assessment record
Rush Lake
The assessment record reported by Iowa to EPA under Clean Water Act sections 303(d) and 305(b), filed in the 2024 reporting cycle, a cycle that carries an interim EPA action.
- 336
- Assessed acres
- Lake
- Water type
- Hypereutrophic
- Reported trophic class
This waterbody in one line
Rush Lake, a lake in Iowa, was reported but not assessed in the state's most recent Integrated Report cycle (2024), a cycle that carries an interim EPA action. By assessed acreage it sits in the upper quartile by assessed acreage nationally (38,628 lakes).
- Not Assessed
- overall status
- P87
- Assessed size nationally
Assessment verdicts are the state agency's decisions as reported to EPA ATTAINS; PlainLakes renders them without modification.
Where Rush Lake 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: assessed size
The number that most separates Rush Lake nationally is assessed size: 336 acres, larger than 87% of the 38,628 lake-type units with an area on file.
IR category 3 on Rush Lake
The Integrated Report category filed for Rush Lake is 3. PlainLakes renders EPA's code without remapping it into a consumer grade.
Overall status: Not Assessed
ATTAINS overall status on this unit is “Not Assessed”. PlainLakes does not rewrite that vocabulary into a consumer score.
According to the U.S. Environmental Protection Agency's ATTAINS program, Iowa carries 371 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Rush Lake 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 - Lakes and Wetlands Warmwater | Aquatic-life or related | Insufficient Information |
| Human Health | Recreation | Insufficient Information |
The record
Listed impairment causes
The state reported this lake in its 2024 Integrated Report cycle but reached no assessment determination, so no causes are listed. The unit is recorded under EPA integrated-reporting Category 3: reviewed, with insufficient information to determine whether it meets water-quality standards. An undetermined waterbody is neither confirmed clean nor confirmed impaired.
Reading the record
What Rush Lake's record holds
Scale and rank
Rush Lake is one of 371 lake-type waterbodies reported to EPA from Iowa. It is not among the 167 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 336 assessed acres it ranks 4,929th 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 4,928 lakes with a larger one.
What this record holds
Iowa filed this lake in its 2024 Integrated Report cycle but reached no determination, so the record holds that filing and its use rows, but no verdict, and with nothing judged, no impairment cause to track over time. The state has not yet filed a definitive fish-consumption verdict, a definitive recreation verdict, a definitive aquatic-life verdict, and 1 other for this record; those fields populate when it reports them in a future Integrated Report cycle.
Reported trophic class
Hypereutrophic is the trophic class the filing agency reported to EPA ATTAINS for this assessment unit. It describes nutrient enrichment, not whether the water is safe, and it is not a PlainLakes inference. What the trophic scale measures.
In context
Where Rush 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
336 Top 13% larger than 87% 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
In both charts each bar is a band and taller bars hold more waterbodies; the dashed line and filled bar mark Rush Lake. Hover or tap any bar for its full count and share.
In context
Iowa context
ATTAINS carries 371 lake-type waterbodies in Iowa, 137 assessed as not supporting at least one use and 66 fully supporting.
| Other large assessed lakes in Iowa | Assessed acres |
|---|---|
| Red Rock Reservoir Not Supporting | 19,000 |
| Rathbun Reservoir - Main Basin Fully Supporting | 6,330 |
| Saylorville Reservoir Not Supporting | 5,950 |
| Coralville Reservoir Not Supporting | 4,900 |
| Big Spirit Lake Fully Supporting | 4,169 |
| Clear Lake Not Supporting | 3,684 |
Lakes near Rush Lake's assessed acres
Similar assessed acres
Nearest filed extents (336 acres here).
- Catherine Lake · 336 acres · AR
- Pine Hill Reservoir · 336 acres · MA
- String · 336 acres · MN
- West Lake · 336 acres · MI
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 IA 06-LSR-1773. 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.