Tropic Reservoir
Garfield County, UtahView mapDirections
Utah DWQ publishes the water-quality measurements for Tropic Reservoir. Here is what has been measured.
- Oligotrophic
- Impaired · pH / acidity
- 13 ft max depth
- Limited data
Tropic Reservoir in Garfield County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 12.3 ft visibility. Phosphorus: 4.9 µg/L. Chlorophyll-a (algae): 1.3 µg/L.
Tropic Reservoir is a cold, clear oligotrophic lake in Garfield County, Utah with an estimated average depth of about 13 feet. Overall water quality is improving over recent sampling years. Compared to the 9 other monitored lakes in Garfield County, Tropic Reservoir ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Utah DWQ, last sampled 2020-08-11. Methodology: how these readings are compared.
What Tropic Reservoir is good for
From access and monitoring records, not editorial picks.
- Clear water12.3 ft of visibility
- Camping3 public campgrounds nearby
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Tropic Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for pH / acidity. Check local advisories before you swim.
Whether Tropic Reservoir is safe to swim in today is a call for the Utah Division of Water Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Tropic Reservoir
These are the measurements Utah DWQ publishes for Tropic Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 12.3 ft. Phosphorus 4.9 µg/L. Chlorophyll-a 1.3 µg/L. TSI 34.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 12.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 4.9µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 1.3µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 34 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Tropic Reservoir
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~13 ft est.
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Utah has not published bathymetry for Tropic Reservoir.
Lake Size & Watershed
Watershed (drainage) area
75 sq mi
HydroLAKES / HydroSHEDS
Surface area
44 acres
HydroLAKES / HydroSHEDS
Shoreline
1.3 mi
HydroLAKES / HydroSHEDS
Elevation
7,844 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
Public campgrounds near Tropic Reservoir
- King Creek Campground0.3 km
- King Creek Group Area0.9 km
- Kings Creek1.0 kmReserve
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Stays via Stay22
Stays near Tropic Reservoir
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Top-rated places to stay near Tropic Reservoir
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Fishing Tropic Reservoir
Water quality readings over time
2 seasons of samples on record (2012–2020). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving2 years
Chlorophyll-a
Stable+0.01 µg/L/yr2 years
Reservoir Info (USACE NID)
Tropic Reservoir is a man-made reservoir impounded by the Tropic (completed 1936), built primarily for irrigation on the East Fork of Sevier River; earth-type dam, 29 ft tall and 752 ft long.
- Normal storage
- 1,850 ac-ft
- Max storage
- 3,700 ac-ft
- Drainage area
- 86.1 sq mi
- Hazard class
- High
- Owner
- TROPIC-EAST FORK IRRIGATION COMPANY
Source: USACE National Inventory of Dams, NID ID UT00302 · Operator website
EPA Impairment Status
Tropic Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life.
Source: EPA ATTAINS assessment unit UT-L-16030002-002_00 · Official waterbody report
Nearby Lakes in Garfield County
Frequently asked questions about Tropic Reservoir
Where is Tropic Reservoir?
- Tropic Reservoir is a lake in Garfield County, Utah. Its water-quality measurements are published by Utah DWQ and shown on this page as reported.
What is the water quality of Tropic Reservoir?
- Tropic Reservoir in Garfield County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 12.3 ft visibility. Phosphorus: 4.9 µg/L. Chlorophyll-a (algae): 1.3 µg/L.
Is Tropic Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Tropic Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for pH / acidity. Check local advisories before you swim.
How deep is Tropic Reservoir?
- No published bathymetric survey covers Tropic Reservoir, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 13 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there campgrounds on Tropic Reservoir?
- Tropic Reservoir has 3 public campgrounds from USGS The National Map within 5 km, including King Creek Campground, King Creek Group Area, Kings Creek. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
Explore Tropic Reservoir across LakeQuality
Planning a trip around Bryce Canyon?
Tropic Reservoir is about 4 miles from Bryce Canyon National Park. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Bryce Canyon →More lakes in Utah
Other Lakes in Utah
Oligotrophic Lakes in Utah
Where this data comes from
11 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Utah Department Of Environmental Quality
UTAHDWQ_WQX11 samples · 2020
Analytical methods
- Field Measurements
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Public campgrounds from USGS The National Map Structures, within about 3 miles