Calder Reservoir
Uintah County, UtahView mapDirections
Utah DWQ publishes the water-quality measurements for Calder Reservoir. Here is what has been measured.
- Mesotrophic
- Impaired · Ammonia
- 14 ft max depth
- Public access
- Limited data
Calder Reservoir in Uintah County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 8.9 ft visibility. Phosphorus: 256 µg/L. Chlorophyll-a (algae): 3.7 µg/L.
Calder Reservoir is a mesotrophic lake in Uintah County, Utah with an estimated average depth of about 14 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 13 other monitored lakes in Uintah County, Calder Reservoir ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, Utah DWQ, last sampled 2023-10-03. Methodology: how these readings are compared.
What Calder Reservoir is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
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. Calder Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for ammonia, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pH / acidity, temperature. Check local advisories before you swim.
Whether Calder 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 Calder Reservoir
These are the measurements Utah DWQ publishes for Calder Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 8.9 ft. Phosphorus 256 µg/L. Chlorophyll-a 3.7 µg/L. TSI 58.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 8.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 256µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 3.7µg/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. | 58 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Calder Reservoir
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~14 ft est.
Public access
Yes
Listed by Utah DWQ
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Utah has not published bathymetry for Calder Reservoir.
Lake Size & Watershed
Watershed (drainage) area
67 sq mi
HydroLAKES / HydroSHEDS
Surface area
49 acres
HydroLAKES / HydroSHEDS
Shoreline
1.3 mi
HydroLAKES / HydroSHEDS
Elevation
7,264 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
- Calder ReservoirPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
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Stays near Calder Reservoir
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Top-rated places to stay near Calder Reservoir
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Fishing Calder Reservoir
Water Quality Trend: Improving
Based on 5 years of monitoring (2012–2023).
Water clarity
Improving5 years
Chlorophyll-a
Improving-3.62 µg/L/yr3 years
Reservoir Info (USACE NID)
Calder Reservoir is a man-made reservoir impounded by the Calder (Zelph) (completed 1989), built primarily for irrigation on the Pot Creek; earth-type dam, 50 ft tall and 374 ft long.
- Normal storage
- 1,600 ac-ft
- Max storage
- 2,600 ac-ft
- Drainage area
- 35 sq mi
- Hazard class
- Significant
- Owner
- DIVISION OF WILDLIFE RESOURCES
Source: USACE National Inventory of Dams, NID ID UT00061 · Operator website · Matched by proximity (0.3 km)
EPA Impairment Status
Calder 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.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit UT-L-14040106-034_00 · Official waterbody report
Nearby Lakes in Uintah County
Frequently asked questions about Calder Reservoir
Where is Calder Reservoir?
- Calder Reservoir is a lake in Uintah County, Utah. Its water-quality measurements are published by Utah DWQ and shown on this page as reported.
What is the water quality of Calder Reservoir?
- Calder Reservoir in Uintah County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 8.9 ft visibility. Phosphorus: 256 µg/L. Chlorophyll-a (algae): 3.7 µg/L.
Is Calder Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Calder Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for ammonia, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pH / acidity, temperature. Check local advisories before you swim.
How deep is Calder Reservoir?
- No published bathymetric survey covers Calder Reservoir, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 14 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 boat ramps on Calder Reservoir?
- Calder Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Calder Reservoir. Public access is listed as yes.
Can I fish at Calder Reservoir?
- Calder Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Utah's fish and wildlife agency, so check its current regulations before you go.
Explore Calder Reservoir across LakeQuality
Planning a trip around Dinosaur?
Calder Reservoir is about 21 miles from Dinosaur National Monument. 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 Dinosaur →More lakes in Utah
Other Lakes in Utah
Mesotrophic Lakes in Utah
Where this data comes from
46 measurements from 1 monitoring station, 2012–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Utah Department Of Environmental Quality
UTAHDWQ_WQX46 samples · 2012–2023
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)
Named boat-access points from the USGS National Boat Ramps inventory