Mill Creek Lake
Calvert County, Maryland97 acresView mapDirections
MDE publishes the water-quality measurements for Mill Creek Lake. Here is what has been measured.
- Impaired · Mercury
- Limited data
Mill Creek Lake in Calvert County, Maryland has water-quality measurements published by MDE, shown here as reported. Water clarity: 3 ft visibility. Surface area: 97.3 acres.
Mill Creek Lake is a 97-acre lake in Calvert County, Maryland. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2022-10-20. Methodology: how these readings are compared.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Mill Creek Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Mill Creek 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 Mill Creek Lake
These are the measurements MDE publishes for Mill Creek Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 3 ft of visibility. TSI 62.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3ft | 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. | 62 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Mill Creek Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
97 acres
No bathymetric survey has been published for Mill Creek Lake, so its depth is not documented here.
Stays via Stay22
Stays near Mill Creek Lake
Compare lakeside cabins, hotels, and vacation rentals near Mill Creek Lake in Calvert County, Maryland — 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 Mill Creek Lake
Prices for Oct 2–4, 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.
Follow Mill Creek Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Mill Creek Lake
Water quality readings over time
2 seasons of samples on record (2021–2022). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Worsening2 years
Reservoir Info (USACE NID)
Mill Creek Lake is a man-made reservoir impounded by the Chesapeake Ranch Estates Dam (Chisolm Trail) (completed 1965), built primarily for recreation on the Mill Creek; earth-type dam, 46 ft tall and 640 ft long.
- Surface area
- 97.3 ac
- Normal storage
- 1,534 ac-ft
- Max storage
- 2,614 ac-ft
- Drainage area
- 2.9 sq mi
- Hazard class
- High
- Owner
- Chesapeake Ranch Estates
Source: USACE National Inventory of Dams, NID ID MD00039 · Operator website · Matched by proximity (0.76 km)
EPA Impairment Status
Mill Creek Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life, Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MD-021311010873-Lake_Lariat · Official waterbody report
Nearby Lakes in Calvert County
Frequently asked questions about Mill Creek Lake
Where is Mill Creek Lake?
- Mill Creek Lake is a lake in Calvert County, Maryland. Its water-quality measurements are published by MDE and shown on this page as reported.
What is the water quality of Mill Creek Lake?
- Mill Creek Lake in Calvert County, Maryland has water-quality measurements published by MDE, shown here as reported. Water clarity: 3 ft visibility. Surface area: 97.3 acres.
Is Mill Creek Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Mill Creek Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Explore Mill Creek Lake across LakeQuality
More lakes in Maryland
Other Lakes in Maryland
Eutrophic Lakes in Maryland
Where this data comes from
132 measurements from 4 monitoring stations, 2021–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples132 samples · 2021–2022
Monitoring station identifiers (4)
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
Impairment status from EPA ATTAINS 303(d) database