Rocky Gap Run Lake
Allegany County, Maryland209 acresView mapDirections
MDE publishes the water-quality measurements for Rocky Gap Run Lake. Here is what has been measured.
- Limited data
Rocky Gap Run Lake in Allegany County, Maryland has water-quality measurements published by MDE, shown here as reported. Water clarity: 13.1 ft visibility. Surface area: 208.5 acres.
Rocky Gap Run Lake is a 209-acre lake in Allegany County, Maryland. Overall water quality is improving over recent sampling years.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2014-10-21. Methodology: how these readings are compared.
What Rocky Gap Run Lake is good for
From access and monitoring records, not editorial picks.
- Clear water13.1 ft of visibility
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Rocky Gap Run Lake is safe to swim in today is a call for the Maryland Department of the Environment and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Rocky Gap Run Lake
These are the measurements MDE publishes for Rocky Gap Run Lake, 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 13.1 ft. TSI 40.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 13.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 40 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Rocky Gap Run Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
209 acres
No bathymetric survey has been published for Rocky Gap Run Lake, so its depth is not documented here.
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Stays near Rocky Gap Run Lake
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Fishing Rocky Gap Run Lake
Water quality readings over time
3 seasons of samples on record (2012–2017). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Reservoir Info (USACE NID)
Rocky Gap Run Lake is a man-made reservoir impounded by the Rocky Gap Dam (completed 1969), built primarily for water supply on the Rocky Gap Run; earth-type dam, 98 ft tall and 800 ft long.
- Surface area
- 208.5 ac
- Normal storage
- 5,381 ac-ft
- Max storage
- 10,048 ac-ft
- Drainage area
- 8.8 sq mi
- Hazard class
- High
- Owner
- MD DNR-Public Lands, Engineering & Constr-Western
All listed purposes: Water Supply;Recreation.
Source: USACE National Inventory of Dams, NID ID MD00071 · Operator website · Matched by proximity (0.17 km)
Nearby Lakes in Allegany County
Frequently asked questions about Rocky Gap Run Lake
Where is Rocky Gap Run Lake?
- Rocky Gap Run Lake is a lake in Allegany County, Maryland. Its water-quality measurements are published by MDE and shown on this page as reported.
What is the water quality of Rocky Gap Run Lake?
- Rocky Gap Run Lake in Allegany County, Maryland has water-quality measurements published by MDE, shown here as reported. Water clarity: 13.1 ft visibility. Surface area: 208.5 acres.
Is Rocky Gap Run Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
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Where this data comes from
126 measurements from 1 monitoring station, 2014. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples126 samples · 2014
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.