Idaho lake · state assessment record
Lower Goose Creek Reservoir
Assessment decisions reported by Idaho to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2014 reporting cycle.
- 1,006
- Assessed acres
- Lake, Freshwater
- Water type
- Mesotrophic
- Reported trophic class
This waterbody in one line
Lower Goose Creek Reservoir, a lake in Idaho, is assessed as not supporting one or more designated uses, with 2 listed impairment causes in the state's most recent Integrated Report cycle (2014). By assessed acreage it sits among the largest 10% 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
- P94
- 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.
Where Lower Goose Creek Reservoir 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 Lower Goose Creek Reservoir nationally is assessed size: 1,006 acres, larger than 94% of the 38,628 lake-type units with an area on file.
Every ruled-on use is not supporting
On the uses this filer ruled on, recreation, aquatic life, every determination is Not Supporting. That is a use-by-use reading of the filed record, not a single overall lake grade.
Lower Goose Creek Reservoir: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Lower Goose Creek Reservoir. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
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.
Overall status: not supporting
The filer's overall status for Lower Goose Creek Reservoir 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, Idaho carries 630 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Lower Goose Creek Reservoir 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. Idaho filed its own confidence on the one definitive verdict it rated: Good. That rating is the filer's, in EPA's own field, and EPA publishes no definition of the four words it offers.
| Designated use | Group | Verdict |
|---|---|---|
| Cold Water Aquatic Life | Aquatic-life or related | Not Supporting Filer confidence: Good |
| Primary Contact Recreation | Recreation | Not Supporting |
| Salmonid Spawning | Aquatic-life or related | Not Supporting |
| Aesthetic | Other | Not Assessed |
| Agricultural Water Supply | Other | Not Assessed |
| Industrial Water Supply | Other | Not Assessed |
| Wildlife Habitat | Other | Not Assessed |
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 |
|---|---|---|---|
| Mercury | Primary Contact Recreation, Cold Water Aquatic Life, Salmonid Spawning | 2006 | TMDL priority: High |
| Flow Regime Modification | Cold Water Aquatic Life | Not reported | None reported |
Reading the record
Cleanup queue for Lower Goose Creek Reservoir
1 listed cause ranked High in the TMDL queue, still without a plan
Idaho ranked Mercury high in its TMDL development queue, and no cleanup plan is on file for that listing yet. That queue rank is the state's own scheduling signal, not an EPA national rule.
A High ranking names a position in the state's plan-writing queue; it is not a measure of how impaired the water is. How listing and cleanup work.
Scale and rank
Lower Goose Creek Reservoir is one of 630 lake-type waterbodies reported to EPA from Idaho, and one of 186 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 1,006 assessed acres it ranks 2,256th 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 2,255 lakes with a larger one.
Not yet on record
The state has not yet filed a definitive fish-consumption verdict for this record; that field populates when it reports it in a future Integrated Report cycle.
Reported trophic class
Mesotrophic 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 Lower Goose Creek Reservoir 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
1,006 Top 6% larger than 94% 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 Lower Goose Creek Reservoir. Hover or tap any bar for its full count and share.
In context
Idaho context
ATTAINS carries 630 lake-type waterbodies in Idaho, 51 assessed as not supporting at least one use and 198 fully supporting. Among the 186 indexed units there, Lower Goose Creek Reservoir ranks 18th by listed-cause count (2 listed causes) and 26th by assessed size among the 186 with an area filed; it sits in the not-supporting set (51 statewide) . Its listed causes include Mercury and Flow Regime Modification, which also appear among Idaho's most-filed impairment causes (led by Phosphorus, Total).
| Other large assessed lakes in Idaho | Assessed acres |
|---|---|
| Pend Oreille Lake Not Supporting | 80,829 |
| Bear Lake Not Assessed | 34,454 |
| American Falls Reservoir (Snake River) Not Supporting | 31,724 |
| Cascade Reservoir Not Supporting | 25,040 |
| American Falls Reservoir (Snake River) Tribal Waters Not Assessed | 23,785 |
| Grays Lake Not Assessed | 23,678 |
Peers near Lower Goose Creek Reservoir's size or cause load
Similar assessed acres
Nearest filed extents (1,006 acres here).
- Beaver Run Reservoir-05010008000631 · 1,006 acres · PA
- Little Trout Lake · 1,007 acres · WI
- Crescent Lake · 1,007 acres · NE
- Lake Loveland, Horseshoe Lake. · 1,008 acres · CO
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 ID17040211SK002L_0L. 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.