Muddy Brook Lake
Worcester County, Massachusetts69 acresView mapDirections
Nutrients and algae run above the regional average.
↓ down from C at the last regrade
- Eutrophic
- Impaired · Algal growth
- #20 of 24 in the county
- 23 ft max depth
- Public access
- Limited data
Muddy Brook Lake in Worcester County, Massachusetts has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 13.8 µg/L. Surface area: 69 acres.
- Max depth
- ~23 ft est.
- Area
- 69 acres
- Type
- Eutrophic
- Chlorophyll-a
- 13.8 µg/L
- Public access
- Yes
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Stays near Muddy Brook Lake
Compare lakeside cabins, hotels, and vacation rentals near Muddy Brook Lake in Worcester County, Massachusetts — 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Muddy Brook Lake are listed below.
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Muddy Brook Lake is a 69-acre productive, nutrient-rich eutrophic lake in Worcester County, Massachusetts with an estimated average depth of about 23 feet. Water quality is graded D based on 1 sampling years through 2016. Limited fish-species data available. Public access is available. Compared to the 23 other monitored lakes in Worcester County, Muddy Brook Lake ranks #20 for water quality.
Source: EPA Water Quality Portal sampling records, MassDEP, last sampled 2016-09-13. Grade methodology: LakeQuality methodology.
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 D is nutrients and algae, not a swimming clearance. Muddy Brook Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury, nuisance exotic species. Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
No clarity data. Chlorophyll-a 13.8 µg/L. TSI 56. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 13.8 µg/L | Poor |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~23 ft est. |
| Average Depth | ~16 ft est. |
| Surface Area | 69 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Massachusetts has not published bathymetry for Muddy Brook Lake.
Lake Size & Watershed
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.
Fishing Muddy Brook Lake
Reservoir Info (USACE NID)
Muddy Brook Lake is a man-made reservoir impounded by the Hardwick Pond Dam, built primarily for recreation on the Muddy Brook; earth-type dam, 8 ft tall and 121 ft long.
- Surface area
- 69 ac
- Normal storage
- 214 ac-ft
- Max storage
- 321 ac-ft
- Drainage area
- 15.6 sq mi
- Hazard class
- Significant
- Owner
- Town of Ware
Source: USACE National Inventory of Dams, NID ID MA00080 · Operator website · Matched by proximity (0.97 km)
EPA Impairment Status
Muddy Brook Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MA36066 · Official waterbody report · Matched by proximity (0.37 km)
County Ranking
Ranked #20 of 24 lakes in Worcester County
Nearby Lakes in Worcester County
Frequently asked questions about Muddy Brook Lake
Where is Muddy Brook Lake?
- Muddy Brook Lake is a lake in Worcester County, Massachusetts. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Muddy Brook Lake?
- Muddy Brook Lake in Worcester County, Massachusetts has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 13.8 µg/L. Surface area: 69 acres.
Is Muddy Brook Lake safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Muddy Brook Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury, nuisance exotic species. Check local advisories before you swim.
How deep is Muddy Brook Lake?
- No published bathymetric survey covers Muddy Brook Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 23 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 69 acres.
Explore Muddy Brook Lake across LakeQuality
Species activity outlook by water temperature and season
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
3 measurements from 1 monitoring station, 2016. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Massachusetts Department of Environmental Protection (MassDEP)
MASSDEP3 samples · 2016
Analytical methods
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)