Colorado reservoir · state assessment record
Vega Reservoir.
Assessment decisions reported by Colorado to EPA under Clean Water Act sections 303(d) and 305(b), last assessed in the 2019 reporting cycle.
- 876
- Assessed acres
- Lake / Reservoir / Pond
- Water type
- 7,929.2 ft
- Water Surface Elevation (provisional)
This waterbody in one line
Vega Reservoir., a reservoir in Colorado, is assessed as not supporting one or more designated uses, with one listed impairment cause in the state's most recent Integrated Report cycle (2019). By assessed acreage it sits among the largest 10% by assessed acreage nationally (38,628 lakes); its impairment list is among the longest nationally (one listed cause vs 23,610 assessed lakes). Aquatic life is assessed as fully supporting. A USGS gauge tracks its water surface elevation daily.
- Not Supporting
- overall status
- P94
- Assessed size nationally
- P20
- 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.
Where Vega 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 Vega Reservoir. nationally is assessed size: 876.4 acres, larger than 94% of the 38,628 lake-type units with an area on file.
Vega Reservoir.: Category 5, TMDL still owed
Category 5 is the Integrated Report band where a TMDL (or equivalent) is still expected for Vega Reservoir.. Read the listed causes and any cleanup actions filed beside them before treating the overall status tile as a finished restoration story.
Every ruled-on use is fully supporting
The filed use determinations for 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.
Overall status: not supporting
The filer's overall status for Vega Reservoir. is Not Supporting. That tile summarizes the assessment unit; the designated-use rows and cause list are the evidence behind it.
Typical cause-list length
1 listed cause is a middle-tercile list length among assessed lake-type units. Look to IR category and use outcomes for the distinctive reading.
According to the U.S. Environmental Protection Agency's ATTAINS program, Colorado carries 344 filed lake-type waterbodies in the August 2026 extract, and this page renders the assessment record EPA assigned to Vega 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. Colorado filed 2016 as the year this waterbody was last monitored.
| Designated use | Group | Verdict |
|---|---|---|
| Agriculture | Other | Fully Supporting |
| Aquatic Life Cold Water-Class 1 | Aquatic-life or related | Fully Supporting |
| Water Supply | Drinking-water supply designation | Not Supporting |
| Recreation | Recreation | 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 |
|---|---|---|---|
| Arsenic | Water Supply | 2020 | TMDL priority: High |
Reading the record
Cleanup queue for Vega Reservoir.
1 listed cause ranked High in the TMDL queue, still without a plan
Colorado ranked Arsenic 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
Vega Reservoir. is one of 344 lake-type waterbodies reported to EPA from Colorado, and one of 122 whose reported record carries enough populated assessment or gauge data for this site to list and index it. At 876 assessed acres it ranks 2,480th 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 2,479 lakes with a larger one.
Water level
A USGS gauge tracks this reservoir's water surface elevation daily, and the latest reading is 14.35 ft below the reading 30 days earlier, against a 365-day observed range of 33.6 ft. 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.
Water level: 365-day record
Daily water surface elevation values, feet above the National Geodetic Vertical Datum of 1929 (NGVD 29), from USGS gauge 09096100 (Vega Reservoir Near Collbran, Co), shown weekly. Readings are daily-batch snapshots, not real-time conditions.
- Latest reading
- 7,929.2 ft 14.350000000000364ft vs 30 days earlier
- 2026-08-15 · Provisional, subject to USGS revision
Water level: 365-day record
Subscribe to water level updates for Vega Reservoir. (RSS)
275 of the 365 daily values in this window (75%) are provisional and subject to USGS revision; USGS has approved this gauge's record through 2025-11-13.
Full gauge record: USGS monitoring location 09096100
In context
Where Vega 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
876 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
1 Longer than most more listed causes than 49% 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 Vega Reservoir.. Hover or tap any bar for its full count and share.
In context
Colorado context
ATTAINS carries 344 lake-type waterbodies in Colorado, 89 assessed as not supporting at least one use and 74 fully supporting. Among the 122 indexed units there, Vega Reservoir. ranks 52nd by listed-cause count (one listed cause) and 29th by assessed size among the 122 with an area filed; it sits in the not-supporting set (89 statewide) . Its listed causes include Arsenic, which also appears among Colorado's most-filed impairment causes (led by Arsenic).
| Other large assessed lakes in Colorado | Assessed acres |
|---|---|
| John Martin Reservoir. Not Supporting | 17,147 |
| Blue Mesa Reservoir Fully Supporting | 8,957 |
| Lake Granby. Not Supporting | 7,036 |
| Two Buttes Reservoir, Two Buttes Pond, Hasty Lake, Holbrook Reservoir, Burchfield Lake, Nee-Skah (Queens) Reservoir, Neeso Pah Reservoir, Nee Noshe Reservoir. Fully Supporting | 6,123 |
| Lake and reserviors tributary to the South Platte River Not Assessed | 5,770 |
| Lake Meredith. Not Supporting | 5,531 |
Peers near Vega Reservoir.'s size or cause load
Similar assessed acres
Nearest filed extents (876 acres here).
- Lake Bonham (Bonham City Lake) · 876 acres · TX
- Big Swan · 877 acres · MN
- Myrtle · 876 acres · MN
- Possum Kingdom Lake · 877 acres · TX
Similar cause load
Nearest listed-cause counts (1 here). Peers already in the acreage column are omitted.
- Aaron · 1 causes · MN
- Aaron River Reservoir · 1 causes · MA
- Abbotts Creek (including Lexington-Thomasville Water Supply Reservoir at normal reservoir elevation, Tom-A-Lex Lake) · 1 causes · NC
- Abeniki Lake · 1 causes · 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
- 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 COLCLC20_D. 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.