Matt Warner Reservoir E
Uintah County, UtahView mapDirections
Utah DWQ publishes the water-quality measurements for Matt Warner Reservoir E. Here is what has been measured.
- Eutrophic
- Impaired · Algal growth
Matt Warner Reservoir E in Uintah County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 6.2 ft visibility. Phosphorus: 72 µg/L. Chlorophyll-a (algae): 15.2 µg/L.
Matt Warner Reservoir E is a productive, nutrient-rich eutrophic lake in Uintah County, Utah. Phosphorus level is declining over recent sampling years. Compared to the 13 other monitored lakes in Uintah County, Matt Warner Reservoir E ranks #13 for water quality.
Source: EPA Water Quality Portal sampling records, Utah DWQ, last sampled 2024-09-30. Methodology: how these readings are compared.
Swimming conditions
Readings onlyRecreation use not supported
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. Matt Warner Reservoir E is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pH / acidity, temperature. Check local advisories before you swim.
Whether Matt Warner Reservoir E 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 Matt Warner Reservoir E
These are the measurements Utah DWQ publishes for Matt Warner Reservoir E, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 6.2 ft. Phosphorus 72 µg/L. Chlorophyll-a 15.2 µg/L. TSI 58.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 6.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 72µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 15.2µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 58 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
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Stays via Stay22
Stays near Matt Warner Reservoir E
Compare lakeside cabins, hotels, and vacation rentals near Matt Warner Reservoir E in Uintah County, Utah — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Matt Warner Reservoir E are listed below.
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Fishing Matt Warner Reservoir E
Water Quality Trend: Stable
Based on 11 years of monitoring (2012–2024).
Water clarity
Stable11 years
Phosphorus
Worsening+3.7 µg/L/yr5 years
Chlorophyll-a
Improving-6.06 µg/L/yr7 years
Reservoir Info (USACE NID)
Matt Warner Reservoir E is a man-made reservoir impounded by the Warner (Matt) (completed 1938), built primarily for irrigation on the Pot Creek; earth-type dam, 38 ft tall and 297 ft long.
- Normal storage
- 3,947 ac-ft
- Max storage
- 6,729 ac-ft
- Drainage area
- 32 sq mi
- Hazard class
- Significant
- Owner
- DIVISION OF WILDLIFE RESOURCES
Source: USACE National Inventory of Dams, NID ID UT00314 · Operator website · Matched by proximity (0.92 km)
EPA Impairment Status
Matt Warner Reservoir E 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, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit UT-L-14040106-033_00 · Official waterbody report
Nearby Lakes in Uintah County
Frequently asked questions about Matt Warner Reservoir E
Where is Matt Warner Reservoir E?
- Matt Warner Reservoir E 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 Matt Warner Reservoir E?
- Matt Warner Reservoir E in Uintah County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 6.2 ft visibility. Phosphorus: 72 µg/L. Chlorophyll-a (algae): 15.2 µg/L.
Is Matt Warner Reservoir E safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Matt Warner Reservoir E is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pH / acidity, temperature. Check local advisories before you swim.
Explore Matt Warner Reservoir E across LakeQuality
Planning a trip around Dinosaur?
Matt Warner Reservoir E is about 26 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
Eutrophic Lakes in Utah
Where this data comes from
79 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Utah Department Of Environmental Quality
UTAHDWQ_WQX79 samples · 2020–2024
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