Lake Frederick-Right Arm
Frederick County, Virginia91 acresView mapDirections
Virginia DEQ publishes the water-quality measurements for Lake Frederick-Right Arm. Here is what has been measured.
- Mesotrophic
Lake Frederick-Right Arm in Frederick County, Virginia has water-quality measurements published by Virginia DEQ, shown here as reported. Water clarity: 9.2 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 4.7 µg/L. Surface area: 91 acres.
Lake Frederick-Right Arm is a 91-acre mesotrophic lake in Frederick County, Virginia. Overall water quality is declining over recent sampling years. Compared to the 1 other monitored lakes in Frederick County, Lake Frederick-Right Arm ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Virginia DEQ, last sampled 2026-07-07. Methodology: how these readings are compared.
Swimming conditions
Readings onlyModerate algae
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 Lake Frederick-Right Arm is safe to swim in today is a call for the Virginia Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lake Frederick-Right Arm
These are the measurements Virginia DEQ publishes for Lake Frederick-Right Arm, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 9.2 ft. Phosphorus 20 µg/L. Chlorophyll-a 4.7 µg/L. TSI 46.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 20µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 4.7µg/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. | 46 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Lake Frederick-Right Arm
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
91 acres
No bathymetric survey has been published for Lake Frederick-Right Arm, so its depth is not documented here.
Stays via Stay22
Stays near Lake Frederick-Right Arm
Compare lakeside cabins, hotels, and vacation rentals near Lake Frederick-Right Arm in Frederick County, Virginia — 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 Lake Frederick-Right Arm
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Virginia’s top lakes →
Follow Lake Frederick-Right Arm’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Lake Frederick-Right Arm
Water Quality Trend: Worsening
Based on 10 years of monitoring (2013–2026).
Water clarity
Worsening10 years
Phosphorus
Worsening+0.58 µg/L/yr10 years
Chlorophyll-a
Worsening+0.14 µg/L/yr10 years
Reservoir Info (USACE NID)
Lake Frederick-Right Arm is a man-made reservoir impounded by the Lake Frederick Dam, built primarily for recreation on the Crooked Run; earth-type dam, 74 ft tall and 680 ft long.
- Surface area
- 91 ac
- Normal storage
- 2,410 ac-ft
- Max storage
- 4,300 ac-ft
- Drainage area
- 3 sq mi
- Hazard class
- High
- Owner
- Virginia Department of Wildlife Resources
Source: USACE National Inventory of Dams, NID ID VA069013 · Operator website · Matched by proximity (0.99 km)
Nearby Lakes in Frederick County
Frequently asked questions about Lake Frederick-Right Arm
Where is Lake Frederick-Right Arm?
- Lake Frederick-Right Arm is a lake in Frederick County, Virginia. Its water-quality measurements are published by Virginia DEQ and shown on this page as reported.
What is the water quality of Lake Frederick-Right Arm?
- Lake Frederick-Right Arm in Frederick County, Virginia has water-quality measurements published by Virginia DEQ, shown here as reported. Water clarity: 9.2 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 4.7 µg/L. Surface area: 91 acres.
Is Lake Frederick-Right Arm safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Lake Frederick-Right Arm across LakeQuality
More lakes in Virginia
Other Lakes in Virginia
Mesotrophic Lakes in Virginia
Where this data comes from
259 measurements from 1 monitoring station, 2013–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- VIRGINIA DEPARTMENT OF ENVIRONMENTAL QUALITY
21VASWCB259 samples · 2013–2026
Analytical methods
- Tyler, John. 1968. The secchi disk, Limnology and Oceanograpy, 13(1):1-6.
- Total Phosphorus After Block Digestion
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 446.0 ~ EPA; Chlorophylls and Pheopigments in Phytoplankton by Spectrophotometry
- 2130 B ~ Nephelometric Method
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.