Idaho lake · state assessment record
Henrys Lake
The assessment record reported by Idaho to EPA under Clean Water Act sections 303(d) and 305(b), filed in the 2014 reporting cycle.
- 6,078
- Assessed acres
- Lake, Freshwater
- Water type
- 13.9 ft
- Gage Height (provisional)
This waterbody in one line
Henrys Lake, a lake in Idaho, was reported but not assessed in the state's most recent Integrated Report cycle (2014). By assessed acreage it sits among the largest 1% of assessed lakes nationally (38,628 lakes with a filed area). A USGS gauge tracks its gage height daily.
- Not Assessed
- overall status
- P99
- Assessed size nationally
Assessment verdicts are the state agency's decisions as reported to EPA ATTAINS; PlainLakes renders them without modification.
How Henrys Lake reads against 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 Henrys Lake nationally is assessed size: 6,078 acres, larger than 99% of the 38,628 lake-type units with an area on file.
IR category 3 on Henrys Lake
The Integrated Report category filed for Henrys 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, Idaho carries 630 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Henrys 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 |
|---|---|---|
| Aesthetic | Other | Not Assessed |
| Agricultural Water Supply | Other | Not Assessed |
| Cold Water Aquatic Life | Aquatic-life or related | Not Assessed |
| Industrial Water Supply | Other | Not Assessed |
| Secondary Contact Recreation | Recreation | Not Assessed |
| Wildlife Habitat | Other | Not Assessed |
The record
Listed impairment causes
The state reported this lake in its 2014 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 Henrys Lake's record holds
Scale and rank
Henrys Lake is one of 630 lake-type waterbodies reported to EPA from Idaho. It is not among the 186 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 6,078 assessed acres it ranks 512th 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 511 lakes with a larger one.
Water level
A USGS gauge tracks this lake's gage height daily, and the latest reading is 1.75 ft below the reading 30 days earlier, against a 365-day observed range of 2.6 ft. 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.
Water level: 365-day record
Daily gage height values, feet above this gauge’s own local zero, not above sea level, from USGS gauge 13039000 (Henrys Lake Nr Lake Id), shown weekly. Readings are daily-batch snapshots, not real-time conditions. Each daily value is a single reading taken at 24:00, not a daily mean. It is the only daily statistic USGS files for this gauge.
- Latest reading
- 13.9 ft 1.75ft vs 30 days earlier
- 2026-08-15 · Provisional, subject to USGS revision
Water level: 365-day record
Subscribe to water level updates for Henrys Lake (RSS)
256 of the 360 daily values in this window (71%) are provisional and subject to USGS revision; USGS has approved this gauge's record through 2025-11-30.
Full gauge record: USGS monitoring location 13039000
In context
Where Henrys 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
6,078 Top 1% larger than 99% 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 Henrys Lake. 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.
| 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 |
Lakes near Henrys Lake's assessed acres
Similar assessed acres
Nearest filed extents (6,078 acres here).
- Ocean Lake · 6,076 acres · WY
- Chautauqua Lake, South · 6,081 acres · NY
- Richland-Chambers Reservoir · 6,076 acres · TX
- Thunderbird Lake · 6,070 acres · OK
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
- Water levels shown are daily snapshots. Seasonal drawdown and datum conventions matter when comparing levels. How to read level data
- 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 ID17040202SK032L_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.