Wyoming reservoir · state assessment record
Brooks Lake
Near Togwotee Pass in Fremont County. Assessment decisions reported by Wyoming to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2018 reporting cycle.
- 209
- Assessed acres
- Lake / Reservoir / Pond
- Water type
This waterbody in one line
Brooks Lake, a reservoir in Wyoming, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2018). By assessed acreage it sits in the upper quartile by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (2 listed causes vs 23,610 assessed lakes). Aquatic life is assessed as not supporting.
- Not Supporting
- overall status
- P82
- Assessed size nationally
- P10
- 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.
Brooks Lake against the ATTAINS 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: monitoring lag
The signature tension is currency: the reporting cycle is 2018 while monitoring evidence runs through 2012, a 6-year gap. Cycle year and last-monitored year move independently in ATTAINS; this page shows both.
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.
Brooks Lake: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Brooks Lake. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
Large assessed unit
At 209 acres, Brooks Lake clears the upper tercile of assessed lake-type units with an area on file (6,937 still larger). Size comparisons use the portal's deduplicated lake ranking population, not raw ATTAINS row counts.
Longer than most cause lists
2 listed causes puts this unit above 80% of assessed lake-type records by list length. Treat that as a coding-and-sampling signal: states that split pollutants finely mint longer lists without proving worse water.
According to the U.S. Environmental Protection Agency's ATTAINS program, Wyoming carries 14 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Brooks 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. Wyoming filed 2012 as the year this waterbody was last monitored.
| Designated use | Group | Verdict |
|---|---|---|
| Aquatic Life Other Than Fish | Aquatic-life or related | Not Supporting |
| Cold Water Fishery | Aquatic-life or related | Not Supporting |
| Non-Game Fish | Aquatic-life or related | Not Supporting |
| Agriculture | Other | Not Assessed |
| Drinking Water | Drinking-water supply designation | Not Assessed |
| Fish Consumption | Fish-consumption or fishery | Not Assessed |
| Industry | Other | Not Assessed |
| Recreation | Recreation | Not Assessed |
| Scenic Value | Other | Not Assessed |
| Wildlife | Other | Not Assessed |
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 |
|---|---|---|---|
| Nutrients | Cold Water Fishery, Aquatic Life Other Than Fish, Non-Game Fish | 2018 | TMDL priority: High |
| pH | Non-Game Fish, Aquatic Life Other Than Fish, Cold Water Fishery | 2018 | TMDL priority: High |
Probable sources
Wyoming listed the source of the impairment as unknown. That is the state's own filed value, not a gap in this record: the cause has been identified, the origin has not.
Reading the record
How current is Brooks Lake's evidence?
6 years between the 2018 reporting cycle and monitoring through 2012
Wyoming filed 2012 as the year this waterbody was last monitored.
The cycle is when the state reported; the monitoring year, where filed, is when it measured. How to read assessment currency.
Scale and rank
Brooks Lake is one of 14 lake-type waterbodies reported to EPA from Wyoming, and one of 8 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 209 assessed acres it ranks 6,938th 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 6,937 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 Brooks 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
209 Top 18% larger than 82% 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
2 Longer than most more listed causes than 80% 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 Brooks Lake. Hover or tap any bar for its full count and share.
In context
Wyoming context
ATTAINS carries 14 lake-type waterbodies in Wyoming, 7 assessed as not supporting at least one use and 6 fully supporting. Among the 8 indexed units there, Brooks Lake ranks 1st by listed-cause count (2 listed causes) and 3rd by assessed size among the 8 with an area filed; it sits in the not-supporting set (7 statewide) . Its listed causes include Nutrients and pH, which also appear among Wyoming's most-filed impairment causes (led by Selenium).
| Other large assessed lakes in Wyoming | Assessed acres |
|---|---|
| Boysen Reservoir Not Assessed | 19,387 |
| Glendo Reservoir Fully Supporting | 12,050 |
| Ocean Lake Not Supporting | 6,076 |
| Meeboer Lake Fully Supporting | 116 |
| Rasmus Lee Lake Not Supporting | 85 |
| Thirty-three Mile Reservoir Not Supporting | 30 |
Peers near Brooks Lake's size or cause load
Similar assessed acres
Nearest filed extents (209 acres here).
- Fourmile Lake · 209 acres · IA
- Lake Rohunta · 209 acres · MA
- Louise · 209 acres · MN
- Sahara · 209 acres · IL
Similar cause load
Nearest listed-cause counts (2 here). Peers already in the acreage column are omitted.
- 12th St. Beach · 2 causes · IL
- 31st St. Beach · 2 causes · IL
- 49th St. Beach · 2 causes · IL
- 57th St. Beach · 2 causes · IL
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 WYBH100800010104_01. 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.