Lake Grampus
Ashley County, ArkansasView mapDirections
Nutrients and algae sit mid-range for this region.
- Eutrophic
- #2 of 3 in the county
- Public access
- Limited data
Lake Grampus in Ashley County, Arkansas has a water quality grade of C (Fair). Phosphorus: 40 µg/L. Chlorophyll-a (algae): 23.8 µg/L.
- Type
- Eutrophic
- Phosphorus
- 40 µg/L
- Chlorophyll-a
- 23.8 µg/L
- Trend
- → Stable
- Public access
- Yes
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Watch Lake Grampus’s letter
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Lake Grampus is a productive, nutrient-rich eutrophic lake in Ashley County, Arkansas. Water quality is graded C based on 3 sampling years through 2025. Phosphorus level is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 2 other monitored lakes in Ashley County, Lake Grampus ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, ADEQ, last sampled 2025-03-10. Grade methodology: LakeQuality methodology.
What Lake Grampus is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
The C is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: C (Fair)
No clarity data. Phosphorus 40 µg/L. Chlorophyll-a 23.8 µg/L. TSI 60. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 40 µg/L | Good |
| Chlorophyll-a (Algae) | 23.8 µg/L | Fair |
| Trophic State Index (TSI) | 60 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Recreation & Access
- Lake GrampusPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Lake Grampus
Water Quality Trend: → Stable
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | ↓ Declining | +5 µg/L/yr | 2 |
| Chlorophyll-a | ↑ Improving | -21.3 µg/L/yr | 2 |
Reservoir Info (USACE NID)
Lake Grampus is a man-made reservoir impounded by the Lake Grampus Dam (completed 1968), built primarily for recreation on the Bayou Bartholomew-Tr; earth-type dam, 16 ft tall and 508 ft long.
- Normal storage
- 960 ac-ft
- Max storage
- 1,320 ac-ft
- Hazard class
- Low
- Owner
- Arkansas Game and Fish Commission
Source: USACE National Inventory of Dams, NID ID AR00685 · Operator website
County Ranking
Ranked #2 of 3 lakes in Ashley County
Nearby Lakes in Ashley County
Frequently asked questions about Lake Grampus
Where is Lake Grampus?
- Lake Grampus is a lake in Ashley County, Arkansas. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lake Grampus?
- Lake Grampus in Ashley County, Arkansas has a water quality grade of C (Fair). Phosphorus: 40 µg/L. Chlorophyll-a (algae): 23.8 µg/L.
Is Lake Grampus safe to swim in?
- The C is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Are there boat ramps on Lake Grampus?
- Lake Grampus has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Grampus. Public access is listed as yes.
Explore Lake Grampus across LakeQuality
More Arkansas Lake Rankings
Other Grade C Lakes in Arkansas
Eutrophic Lakes in Arkansas
Where this data comes from
31 measurements from 1 monitoring station, 2019–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Arkansas Department of Environmental Quality
ARDEQH2O_WQX31 samples · 2019–2025
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)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Named boat-access points from the USGS National Boat Ramps inventory