Miller Flat Reservoir
Emery County, UtahView mapDirections
Utah DWQ publishes the water-quality measurements for Miller Flat Reservoir. Here is what has been measured.
- Mesotrophic
- Limited data
Miller Flat Reservoir in Emery County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 10.2 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 4.5 µg/L.
Miller Flat Reservoir is a mesotrophic lake in Emery County, Utah. Overall water quality is declining over recent sampling years. Compared to the 9 other monitored lakes in Emery County, Miller Flat Reservoir ranks #10 for water quality.
Source: EPA Water Quality Portal sampling records, Utah DWQ, last sampled 2025-09-23. Methodology: how these readings are compared.
What Miller Flat Reservoir is good for
From access and monitoring records, not editorial picks.
- Clear water10.2 ft of visibility
- Camping1 public campground 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. Check local advisories before you swim.
Whether Miller Flat 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 Miller Flat Reservoir
These are the measurements Utah DWQ publishes for Miller Flat 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 10.2 ft. Phosphorus 13.5 µg/L. Chlorophyll-a 4.5 µg/L. TSI 44.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 13.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 4.5µg/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. | 44 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Miller Flat Reservoir
Answers come straight from the public measurements and survey records on this page.
Recreation & Access
Public campgrounds near Miller Flat Reservoir
- Miller Flat Reservoir Campground2.1 km
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 Miller Flat Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Miller Flat Reservoir in Emery 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 Miller Flat Reservoir are listed below.
Top-rated places to stay near Miller Flat Reservoir
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
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Fishing Miller Flat Reservoir
Water quality readings over time
2 seasons of samples on record (2019–2025). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Worsening2 years
Chlorophyll-a
Stable0 µg/L/yr2 years
Reservoir Info (USACE NID)
Miller Flat Reservoir is a man-made reservoir impounded by the Miller Flat (completed 1949), built primarily for irrigation on the Miller Flat Creek; earth-type dam, 73 ft tall and 835 ft long.
- Normal storage
- 5,560 ac-ft
- Max storage
- 6,393 ac-ft
- Drainage area
- 9 sq mi
- Hazard class
- High
- Owner
- HUNTINGTON-CLEVELAND IRRIGATION COMPANY
Source: USACE National Inventory of Dams, NID ID UT00210 · Operator website
Nearby Lakes in Emery County
Frequently asked questions about Miller Flat Reservoir
Where is Miller Flat Reservoir?
- Miller Flat Reservoir is a lake in Emery County, Utah. Its water-quality measurements are published by Utah DWQ and shown on this page as reported.
What is the water quality of Miller Flat Reservoir?
- Miller Flat Reservoir in Emery County, Utah has water-quality measurements published by Utah DWQ, shown here as reported. Water clarity: 10.2 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 4.5 µg/L.
Is Miller Flat Reservoir safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Are there campgrounds on Miller Flat Reservoir?
- Miller Flat Reservoir has 1 public campground from USGS The National Map within 5 km, including Miller Flat Reservoir Campground. 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 Miller Flat Reservoir across LakeQuality
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Other Lakes in Utah
Mesotrophic Lakes in Utah
Where this data comes from
17 measurements from 1 monitoring station, 2019–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Utah Department Of Environmental Quality
UTAHDWQ_WQX17 samples · 2019–2025
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
Public campgrounds from USGS The National Map Structures, within about 3 miles