Iowa lake · state assessment record

Avenue Of The Saints Lake

Assessment decisions reported by Iowa to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2024 reporting cycle, a cycle that carries an interim EPA action.

30
Assessed acres
Lake
Water type
Hypereutrophic
Reported trophic class
View watchlist

This waterbody in one line

Avenue Of The Saints Lake, a lake in Iowa, is assessed as not supporting one or more designated uses, with 3 listed impairment causes in the state's most recent Integrated Report cycle (2024), a cycle that carries an interim EPA action. By assessed acreage it sits below the national median by assessed acreage (38,628 lakes); its impairment list is among the longest nationally (3 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.

Not Supporting
overall status
P42
Assessed size nationally
P5
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.

F
Water Quality Standing
30/100
Avenue Of The Saints Lake

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.

RecreationN/A
Not assessed
Swimming, boating, and other primary/secondary contact recreation
Drinking WaterN/A
Not assessed
Suitability as a public drinking-water source
Aquatic LifeF
Not supporting
Support for fish, invertebrates, and other aquatic organisms
Fish ConsumptionN/A
Not assessed
Safety of eating fish caught in this water
Impairment BurdenF
3 causes
Filed pollutant/stressor causes, vs. the national corpus of assessed active units
Assessment CurrencyA+
2024
Reporting cycle this record’s verdicts were last decided in

Where Avenue Of The Saints 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: cause-list length

The standout filed fact is cause-list length: 3 listed impairment causes, a longer list than 90% of assessed lake-type units (n=23,610). List length tracks how states sample and code, not a severity score.

Every filed use falls short

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.

Avenue Of The Saints Lake: Category 4A reading

Category 4A means a TMDL (or equivalent) is already approved for the impairment on Avenue Of The Saints Lake. The remaining work is implementation and tracking, read the cleanup-standing and cause rows for what the state already committed to address.

Overall status: not supporting

The filer's overall status for Avenue Of The Saints Lake is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.

Small within Iowa

State size rank 128 of 167 puts Avenue Of The Saints Lake toward the small end of Iowa's indexed lake-type units with an area.

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 Avenue Of The Saints Lake without modification. See our methodology for reporting-unit limits and gauge linking rules.

Interim EPA action. Iowa decided this in its 2024 Integrated Report, which carries an interim EPA action and has not been finalized. The decisions below are what Iowa has proposed for that cycle; they can change before EPA takes final action on the cycle.
Reporting cycle
2024
Interim EPA action
Listing category
Category 4A
Uses with verdicts
1
Definitive use assessments
Sources retrieved
2026-08-17
Portal-wide ATTAINS + NWIS pull

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 Not Supporting
Human Health Recreation Insufficient Information

The record

Listed impairment causes

Causes the state listed as impairing designated uses of this lake, 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 Aquatic Life - Lakes and Wetlands Warmwater 2004 TMDL approved
Turbidity Aquatic Life - Lakes and Wetlands Warmwater 2004 TMDL approved
pH Aquatic Life - Lakes and Wetlands Warmwater 2016 TMDL approved

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
Agriculture (suspected)
Turbidity
Erosion and Sedimentation (suspected)
pH
Internal Nutrient Recycling (suspected)

Reading the record

Avenue Of The Saints Lake: Category 4A reading

4A Category 4A: impaired, TMDL completed

Iowa filed this assessment unit as Category 4A: impaired, with a pollutant-budget TMDL already completed under 303(d). The listing remains an impairment finding; the plan is on file rather than still awaiting write-up.

How listing and cleanup work.

Scale and rank

Avenue Of The Saints Lake is one of 371 lake-type waterbodies reported to EPA from Iowa, and one of 167 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 30 assessed acres it ranks 22,280th 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 22,279 lakes with a larger one.

Not yet on record

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.

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 Avenue Of The Saints 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

30 Top 58% larger than 42% 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

3 Longer than most more listed causes than 90% 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 Avenue Of The Saints 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. Among the 167 indexed units there, Avenue Of The Saints Lake ranks 26th by listed-cause count (3 listed causes) and 128th by assessed size among the 167 with an area filed; it sits in the not-supporting set (137 statewide) . Its listed causes include Chlorophyll-a, Turbidity, and pH, which also appear among Iowa's most-filed impairment causes (led by Chlorophyll-a).

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

Peers near Avenue Of The Saints Lake's size or cause load

Similar assessed acres

Nearest filed extents (30 acres here).

Similar cause load

Nearest listed-cause counts (3 here). Peers already in the acreage column are omitted.

How peers are picked

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 02-SHL-1790. 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.