Arizona lake · state assessment record
Lakeside Lake
Assessment decisions reported by Arizona to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2026 reporting cycle.
- 15
- Assessed acres
- Lake, Freshwater
- Water type
- Hypereutrophic
- Reported trophic class
This waterbody in one line
Lakeside Lake, a lake in Arizona, is assessed as not supporting one or more designated uses, with 3 listed impairment causes 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 (3 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting. Fish consumption is assessed as fully supporting.
- Not Supporting
- overall status
- P26
- 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.
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 Lakeside 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.
A split ruling across uses
This record splits: Not Supporting on aquatic life, Fully Supporting on fish consumption, recreation. The divergence is inside the designated-use matrix, not a single all-or-nothing label.
Lakeside Lake: Category 4A reading
Category 4A means a TMDL (or equivalent) is already approved for the impairment on Lakeside Lake. The remaining work is implementation and tracking, read the cleanup-standing and cause rows for what the state already committed to address.
Small within Arizona
State size rank 41 of 44 puts Lakeside Lake toward the small end of Arizona's indexed lake-type units with an area.
Overall status: not supporting
The filer's overall status for Lakeside 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, Arizona carries 78 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Lakeside 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 and Wildlife (Warmwater Fishery) | Aquatic-life or related | Not Supporting |
| Fish Consumption | Fish-consumption or fishery | Fully Supporting |
| Partial Body Contact | Recreation | Fully Supporting |
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 |
|---|---|---|---|
| Aquatic Plants (Macrophytes) | Aquatic and Wildlife (Warmwater Fishery) | 2004 | TMDL approved |
| Nitrogen, Total | Aquatic and Wildlife (Warmwater Fishery) | 2004 | TMDL approved |
| Phosphorus | Aquatic and Wildlife (Warmwater Fishery) | 2004 | TMDL approved |
Reading the record
Lakeside Lake: Category 4A reading
4A Category 4A: impaired, TMDL completed
Arizona 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.
Scale and rank
Lakeside Lake is one of 78 lake-type waterbodies reported to EPA from Arizona, and one of 44 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 15 assessed acres it ranks 28,377th 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 28,376 lakes with a larger one.
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 Lakeside 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
15 Top 74% larger than 26% 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 Lakeside Lake. Hover or tap any bar for its full count and share.
In context
Arizona context
ATTAINS carries 78 lake-type waterbodies in Arizona, 34 assessed as not supporting at least one use and 20 fully supporting. Among the 44 indexed units there, Lakeside Lake ranks 5th by listed-cause count (3 listed causes) and 41st by assessed size among the 44 with an area filed; it sits in the not-supporting set (34 statewide) . Its listed causes include Nitrogen, Total, which also appears among Arizona's most-filed impairment causes (led by Mercury in Fish Tissue). It also lists Aquatic Plants (Macrophytes) and Phosphorus, outside that top-five list.
| Other large assessed lakes in Arizona | Assessed acres |
|---|---|
| Lake Mohave Not Supporting | 27,044 |
| Lake Havasu Not Supporting | 19,780 |
| Roosevelt Lake Not Supporting | 18,345 |
| Lake Powell Not Supporting | 9,770 |
| Lake Pleasant Not Supporting | 8,000 |
| Topock Marsh Not Assessed | 4,870 |
Peers near Lakeside Lake's size or cause load
Similar assessed acres
Nearest filed extents (15 acres here).
- Anglers Roachtown · 15 acres · IL
- Apollo Lake · 15 acres · MO
- Artist Lake · 15 acres · NY
- Big Bass Lake · 15 acres · IN
Similar cause load
Nearest listed-cause counts (3 here). Peers already in the acreage column are omitted.
- 67th St. Beach · 3 causes · IL
- Abiquiu Reservoir · 3 causes · NM
- Absecon Creek (AC Reserviors) (gage to SB) · 3 causes · NJ
- Absecon Creek (below gage) · 3 causes · NJ
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 AZL15050302-0760_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.