Diamond Lake
Izard County, Arkansas116 acresView mapDirections
Arkansas DEQ publishes the water-quality measurements for Diamond Lake. Here is what has been measured.
- Oligotrophic
- 33 ft max depth
- Limited data
Diamond Lake in Izard County, Arkansas has water-quality measurements published by Arkansas DEQ, shown here as reported. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Surface area: 116 acres.
Diamond Lake is a 116-acre cold, clear oligotrophic lake in Izard County, Arkansas with an estimated average depth of about 33 feet. Compared to the 1 other monitored lakes in Izard County, Diamond Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, ADEQ, last sampled 2026-02-09. Methodology: how these readings are compared.
Diamond Lake covers about 120 acres in Izard County. For a place on the water, look through cabin and lake-house rentals near Diamond Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
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 Diamond Lake is safe to swim in today is a call for the Arkansas Division of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Diamond Lake
These are the measurements Arkansas DEQ publishes for Diamond Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 20 µg/L. Chlorophyll-a 1.9 µg/L. TSI 42.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 20µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 1.9µg/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. | 42 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Diamond Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~33 ft est.
Surface area
116 acres
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Arkansas has not published bathymetry for Diamond Lake.
Lake Size & Watershed
Watershed (drainage) area
2 sq mi
HydroLAKES / HydroSHEDS
Shoreline
2.3 mi
HydroLAKES / HydroSHEDS
Elevation
722 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.
Stays via Stay22
Stays near Diamond Lake
Compare lakeside cabins, hotels, and vacation rentals near Diamond Lake in Izard County, Arkansas — 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.
Top-rated places to stay near Diamond Lake
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Fishing Diamond Lake
Water quality readings over time
3 seasons of samples on record (2012–2025). Calling a direction takes at least 4 years of the same measurement.
Chlorophyll-a
Stable+0.03 µg/L/yr3 years
Reservoir Info (USACE NID)
Diamond Lake is a man-made reservoir impounded by the Diamond Lake Dam (completed 1974), built primarily for recreation on the Bens Creek; earth-type dam, 74 ft tall and 936 ft long.
- Surface area
- 116 ac
- Normal storage
- 2,360 ac-ft
- Max storage
- 3,000 ac-ft
- Drainage area
- 1.9 sq mi
- Hazard class
- Low
- Owner
- Horseshoe Bend MRID
Source: USACE National Inventory of Dams, NID ID AR00228 · Operator website
Nearby Lakes in Izard County
Frequently asked questions about Diamond Lake
Where is Diamond Lake?
- Diamond Lake is a lake in Izard County, Arkansas. Its water-quality measurements are published by Arkansas DEQ and shown on this page as reported.
What is the water quality of Diamond Lake?
- Diamond Lake in Izard County, Arkansas has water-quality measurements published by Arkansas DEQ, shown here as reported. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Surface area: 116 acres.
Is Diamond Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Diamond Lake?
- No published bathymetric survey covers Diamond Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 33 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 116 acres.
Explore Diamond Lake across LakeQuality
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Oligotrophic Lakes in Arkansas
Where this data comes from
31 measurements from 1 monitoring station, 2012–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Arkansas Department of Environmental Quality
ARDEQH2O_WQX31 samples · 2012–2026
Analytical methods
- 4500 P J ~ Persulfate Method for Simultaneous Determination of Total Nitrogen and Total Phosphorus
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- Turbidity by Nephelometry
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
Lake size & watershed from HydroLAKES (HydroSHEDS)