California reservoir · state assessment record
Rancho Seco Lake (Sacramento County)
The assessment record reported by California to EPA under Clean Water Act sections 303(d) and 305(b), filed in the 2026 reporting cycle.
- 160
- Assessed acres
- Lake / Reservoir / Pond
- Water type
This waterbody in one line
Rancho Seco Lake (Sacramento County), a reservoir in California, was reported but not assessed in the state's most recent Integrated Report cycle (2026). By assessed acreage it sits in the upper quartile by assessed acreage nationally (38,628 lakes).
- Not Assessed
- overall status
- P78
- Assessed size nationally
Assessment verdicts are the state agency's decisions as reported to EPA ATTAINS; PlainLakes renders them without modification.
Where Rancho Seco Lake (Sacramento County) 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 Rancho Seco Lake (Sacramento County) nationally is assessed size: 160.5 acres, larger than 78% of the 38,628 lake-type units with an area on file.
IR category 3 on Rancho Seco Lake (Sacramento County)
The Integrated Report category filed for Rancho Seco Lake (Sacramento County) 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, California carries 607 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Rancho Seco Lake (Sacramento County) 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 |
|---|---|---|
| Commercial and Sport Fishing | Fish-consumption or fishery | Insufficient Information |
| Wildlife Habitat | Other | Insufficient Information |
The record
Listed impairment causes
The state reported this reservoir in its 2026 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 Rancho Seco Lake (Sacramento County)'s record holds
Scale and rank
Rancho Seco Lake (Sacramento County) is one of 607 lake-type waterbodies reported to EPA from California. It is not among the 195 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 160 assessed acres it ranks 8,511th 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 8,510 lakes with a larger one.
What this record holds
California filed this reservoir in its 2026 Integrated Report cycle but reached no determination, so the record holds that filing and its use rows, but no verdict, and with nothing judged, no impairment cause to track over time. 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.
In context
Where Rancho Seco Lake (Sacramento County) 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
160 Top 22% larger than 78% 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 Rancho Seco Lake (Sacramento County). Hover or tap any bar for its full count and share.
In context
California context
ATTAINS carries 607 lake-type waterbodies in California, 202 assessed as not supporting at least one use and 22 fully supporting.
| Other large assessed lakes in California | Assessed acres |
|---|---|
| Salton Sea Not Supporting | 233,045 |
| Tahoe, Lake Not Supporting | 84,092 |
| Goose Lake (Modoc County) Not reported | 62,385 |
| Honey Lake Not Supporting | 55,526 |
| Klamath River HU, Tule Lake and Lower Klamath Lake National Wildlife Refuge Not Supporting | 48,791 |
| Mono Lake Not Supporting | 45,299 |
Lakes near Rancho Seco Lake (Sacramento County)'s assessed acres
Similar assessed acres
Nearest filed extents (160 acres here).
- Kiesz Lake · 161 acres · SD
- Dutch · 160 acres · MN
- Miller Flat Reservoir · 161 acres · UT
- Blaisdell Lake · 161 acres · NH
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 CAL5311100020190716047395. 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.