California reservoir · state assessment record
Milton Reservoir (Nevada County)
Assessment decisions reported by California to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2020 reporting cycle.
- 28
- Assessed acres
- Lake / Reservoir / Pond
- Water type
This waterbody in one line
Milton Reservoir (Nevada County), a reservoir in California, is assessed as fully supporting its designated uses, with no impairment causes listed in the state's most recent Integrated Report cycle (2020). By assessed acreage it sits below the national median by assessed acreage (38,628 lakes); its impairment list is shorter than on half of assessed lakes (0 listed causes). Aquatic life is assessed as fully supporting.
- Fully Supporting
- overall status
- P41
- Assessed size nationally
- P51
- Shorter cause list
- Fully 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.
How Milton Reservoir (Nevada County) 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: cause-list length
The standout filed fact is a short cause list: 0 causes, shorter than 51% of assessed lake-type units. A short list can mean a focused impairment, or a shallow assessment.
All ruled-on uses pass
The filed use determinations for recreation, aquatic life are all Fully Supporting. Where an overall IR category still flags the unit, look at the cause list and report standing rather than treating the use row as empty.
IR category in the supporting band
EPA's Integrated Report category for Milton Reservoir (Nevada County) is 1. In ATTAINS that band means the assessed uses are supporting (or supporting with other waters in the unit), so the narrative weight shifts to how deep the assessment went and whether monitoring is current, not to a restoration plan.
Overall status: fully supporting
Overall status is Fully Supporting. If an IR category or cause row still appears, it usually reflects a prior listing path or a use the overall rollup does not collapse, read those sections rather than stopping at the tile.
Small within California
State size rank 163 of 195 puts Milton Reservoir (Nevada County) toward the small end of California's indexed lake-type units with an area.
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 Milton Reservoir (Nevada 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 |
|---|---|---|
| Cold Freshwater Habitat | Aquatic-life or related | Fully Supporting |
| Municipal and Domestic Supply | Drinking-water supply designation | Fully Supporting |
| Non-Contact Water Recreation | Recreation | Fully Supporting |
| Spawning, Reproduction, and/Or Early Development | Aquatic-life or related | Fully Supporting |
| Water Contact Recreation | Recreation | Fully Supporting |
The record
Listed impairment causes
The state's reported assessment lists no impairment causes for this reservoir.
Reading the record
Milton Reservoir (Nevada County): Category 1 reading
1 Category 1: all designated uses supported
California filed this assessment unit as Category 1: every designated use assessed here was reported as supported. That is the filer's Integrated Report classification, not a PlainLakes score.
Scale and rank
Milton Reservoir (Nevada County) is one of 607 lake-type waterbodies reported to EPA from California, and one of 195 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 28 assessed acres it ranks 22,947th 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 22,946 lakes with a larger one.
What this record holds
California completed an assessment here and listed no impairment cause, so the record holds a verdict and its supporting use rows but no pollutant to track over time. 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.
In context
Where Milton Reservoir (Nevada 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
28 Top 59% larger than 41% 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
0 Among the shortest cause lists fewer listed causes than 51% 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 Milton Reservoir (Nevada 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. Among the 195 indexed units there, Milton Reservoir (Nevada County) ranks 195th by listed-cause count (no listed causes) and 163rd by assessed size among the 195 with an area filed; it is one of the 22 fully-supporting indexed records in the state .
| 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 |
Peers near Milton Reservoir (Nevada County)'s size or cause load
Similar assessed acres
Nearest filed extents (28 acres here).
- Carlson · 28 acres · MN
- Clay Lake · 28 acres · WI
- Crest View Lake · 28 acres · NY
- Hyde Park Lake · 28 acres · NY
Similar cause load
Nearest listed-cause counts (0 here). Peers already in the acreage column are omitted.
- 31st Street Harbor · 0 causes · IL
- 42nd Avenue East Beach · 0 causes · MN
- 59th Street Harbor · 0 causes · IL
- 657 Dunleavy (Beach) · 0 causes · MI
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 CAL5174201020200615044845. 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.