The research behind the mission.
Utah Waterways: A Submerged Debris Atlas: Fathom Restoration's documented and estimated inventory of submerged vehicles, vessels, aircraft, and structural losses across 20 Utah lakes and reservoirs, with every confirmed item traced to a named public source.
What's down there, and how we know.
Confirmed means individually documented: every confirmed item is tied to a named news report, government record, court filing, academic study, or salvage case file. Estimated adds the defensible range our methodology supports. Updated August 4, 2026.
The confirmed mix: 56 vehicles, 103 boats and personal watercraft, 15 aircraft, and 52 structural objects, from bridge pilings to a 400-pound safe.
How the numbers are built.
Every figure on this page is reproducible from public sources. Here is exactly how each is derived, and what we retired on August 4, 2026.
Documented vs. estimated
"Documented" counts individually sourced incidents, each tied to a news source, government record, court filing, peer-reviewed study, or salvage operator case file. "Estimated" adds a defensible range implied by patterns but not individually documented.
Category-based fluids
Fluid capacities come from manufacturer specifications by category, not a flat per-item rule: vehicles ~5 gal of non-fuel fluids, vessels ~2, piston aircraft ~2.5, structures zero. Non-fuel fluids aboard the 226 confirmed items: roughly 520 gallons.
Fuel is an assumption
No agency publishes fuel volumes for a typical submerged vehicle, so fuel is always stated as an assumption. With partial to near-full tanks assumed, total fluids aboard confirmed items land between roughly 2,000 and 3,700 gallons. No per-lake gallons.
The legal standard
Under the Clean Water Act, an oil discharge is harmful the moment it causes "a film or sheen upon or discoloration of the surface of the water" (40 CFR Part 110). USGS documents oil from a 1979 spill near Bemidji, Minnesota still contaminating groundwater today.
We retired our old headline numbers.
Earlier editions of this page led with 9,980 gallons of fluids and 7.64 billion gallons of water at risk. When we re-checked every statistic against its primary source, the dispersion math behind those figures did not hold up, so we removed it everywhere and rebuilt this page on the numbers above. The honest count makes the case on its own.
Read the full correctionAll 20 lakes at a glance.
Sorted by documented count. "Documented" is the count of individually sourced incidents; "Estimated" is the defensible range from the research methodology. Full per-lake source lists are in the PDF atlas.
| Lake / Reservoir | Status | Surface | Documented | Estimated |
|---|---|---|---|---|
| Lake Powell (Utah portion) | Priority | 254 sq mi | 53 | 100–200 |
| Bear Lake | Monitored | 109 sq mi | 37 | 35–80 |
| Great Salt Lake 303(d) impaired | Priority | 950 sq mi | 30 | 35–60 |
| Pineview Reservoir | Priority | 4.4 sq mi | 23 | 18–35 |
| Flaming Gorge Reservoir | Monitored | 66 sq mi | 18 | 25–100 |
| Utah Lake | Priority | 148 sq mi | 16 | 25–60 |
| Strawberry Reservoir | Monitored | 26 sq mi | 10 | 12–30 |
| Deer Creek Reservoir | Priority | 4.6 sq mi | 6 | 8–25 |
| Jordanelle Reservoir | Priority | 5.1 sq mi | 6 | 6–20 |
| Quail Creek Reservoir | Monitored | 1.4 sq mi | 5 | 5–20 |
| Sand Hollow Reservoir | Monitored | 2.4 sq mi | 4 | 4–15 |
| Rockport Reservoir | Monitored | 1.0 sq mi | 4 | 3–10 |
| Yuba Reservoir | Monitored | 16.7 sq mi | 3 | 2–12 |
| East Canyon Reservoir | Monitored | 0.7 sq mi | 3 | 3–10 |
| Fish Lake | Monitored | 4.1 sq mi | 2 | 2–10 |
| Panguitch Lake | Monitored | 1.6 sq mi | 2 | 1–6 |
| Otter Creek Reservoir | Monitored | 4.0 sq mi | 2 | 1–5 |
| Echo Reservoir | Monitored | 1.6 sq mi | 1 | 2–8 |
| Mantua Reservoir | Monitored | 0.86 sq mi | 1 | 0–3 |
| Causey Reservoir | Monitored | 0.3 sq mi | 0 | 0–3 |
| 20 lakes & reservoirs | 226 | 499 total |
Read the full atlas, with per-lake source lists.
The complete atlas documents every individually sourced incident lake by lake, with its primary source, plus the counting and fluid methodology in full. Updated August 4, 2026.
We'll email you the full atlas and add you to the Fathom Dispatch. Short field notes on which lake we're studying and what the records show. Unsubscribe anytime. Prefer email? Just ask us directly.
Where this research goes next.
The citation chain.
Every derived figure on this page traces back to a public authority. Underlying incident sources are listed per lake in the PDF atlas.
- U.S. EPA, oil discharge regulations (40 CFR Part 110): any oil that causes "a film or sheen upon or discoloration of the surface of the water" is a harmful, reportable discharge.
- USGS, National Crude Oil Spill Fate and Natural Attenuation Research Site (Bemidji, MN): field documentation of oil persisting in groundwater more than four decades after a 1979 spill.
- Manufacturer fluid-capacity specifications: the per-category basis for the non-fuel fluid floor (vehicles, vessels, piston aircraft).
- U.S. Bureau of Reclamation: Great Salt Lake restoration funding ($50M+, greatsaltlake.utah.gov, 2024).
- Utah Division of Water Resources: reservoir and watershed data.
- Per-lake incident records: news reporting, government records, court filings, peer-reviewed studies, and salvage operator case files (detailed in the PDF).