Crystal Lake
Essex County, Massachusetts170 acresView mapDirections
Clarity, phosphorus, and algae all sit in the cleanest band for this region.
- Mesotrophic
- Impaired · Mercury
- #2 of 7 in the county
- 26 ft max depth
- Limited data
Crystal Lake in Essex County, Massachusetts has a water quality grade of A (Excellent). Chlorophyll-a (algae): 3.1 µg/L. Surface area: 170 acres.
- Max depth
- ~26 ft est.
- Area
- 170 acres
- Type
- Mesotrophic
- Chlorophyll-a
- 3.1 µg/L
Stays via Stay22
Stays near Crystal Lake
Compare lakeside cabins, hotels, and vacation rentals near Crystal Lake in Essex 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.
Top-rated places to stay near Crystal Lake
Prices for Sep 11–13, 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 Massachusetts’s top lakes →
Watch Crystal Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Crystal Lake is a 170-acre mesotrophic lake in Essex County, Massachusetts with an estimated average depth of about 26 feet. Water quality is graded A based on 1 sampling years through 2017. Compared to the 6 other monitored lakes in Essex County, Crystal Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, MassDEP, last sampled 2017-09-21. 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 A is nutrients and algae, not a swimming clearance. Crystal Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Water Quality Grade: A (Excellent)
No clarity data. Chlorophyll-a 3.1 µg/L. TSI 42. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 3.1 µg/L | Good |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~26 ft est. |
| Average Depth | ~16 ft est. |
| Surface Area | 170 acres |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Massachusetts has not published bathymetry for Crystal 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 Crystal Lake
Reservoir Info (USACE NID)
Crystal Lake is a man-made reservoir impounded by the Crystal Lake Dam (completed 1930), built primarily for water supply on the Creek Brook; concrete-type dam, 8 ft tall and 285 ft long.
- Surface area
- 170 ac
- Normal storage
- 2,417 ac-ft
- Max storage
- 2,762 ac-ft
- Drainage area
- 1.74 sq mi
- Hazard class
- Significant
- Owner
- City of Haverhill
Source: USACE National Inventory of Dams, NID ID MA01140 · Operator website
EPA Impairment Status
Crystal 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 MA84010 · Official waterbody report
County Ranking
Ranked #2 of 7 lakes in Essex County
Nearby Lakes in Essex County
Frequently asked questions about Crystal Lake
Where is Crystal Lake?
- Crystal Lake is a lake in Essex County, Massachusetts. LakeQuality grades it A for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Crystal Lake?
- Crystal Lake in Essex County, Massachusetts has a water quality grade of A (Excellent). Chlorophyll-a (algae): 3.1 µg/L. Surface area: 170 acres.
Is Crystal Lake safe to swim in?
- The A is nutrients and algae, not a swimming clearance. Crystal Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
How deep is Crystal Lake?
- No published bathymetric survey covers Crystal Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 26 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 170 acres.
Explore Crystal Lake across LakeQuality
Species activity outlook by water temperature and season
Where to stay at Massachusetts's top lakes, each with its grade
Moderate nutrients, good water quality
Massachusetts's cleanest and most-polluted lakes, ranked
More Massachusetts Lake Rankings
Other Grade A Lakes in Massachusetts
Mesotrophic Lakes in Massachusetts
Where this data comes from
3 measurements from 1 monitoring station, 2017. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Massachusetts Department of Environmental Protection (MassDEP)
MASSDEP3 samples · 2017
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)