Monponsett Pond
Plymouth County, MassachusettsView mapDirections
Nutrients and algae run above the regional average.
↓ down from C at the last regrade
- Eutrophic
- Impaired · Algal growth
- #9 of 12 in the county
- 39 ft max depth
- Public access
- Limited data
Monponsett Pond in Plymouth County, Massachusetts has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 13 µg/L.
- Max depth
- ~39 ft est.
- Type
- Eutrophic
- Chlorophyll-a
- 13 µg/L
- Trend
- ↑ Improving
- Public access
- Yes
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Stays near Monponsett Pond
Compare lakeside cabins, hotels, and vacation rentals near Monponsett Pond in Plymouth 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 Monponsett Pond are listed below.
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Watch Monponsett Pond’s letter
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Monponsett Pond is a productive, nutrient-rich eutrophic lake in Plymouth County, Massachusetts with an estimated average depth of about 39 feet. Water quality is graded D based on 1 sampling years through 2019. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 11 other monitored lakes in Plymouth County, Monponsett Pond ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, MassDEP, last sampled 2019-09-17. Grade methodology: LakeQuality methodology.
What Monponsett Pond is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
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. Monponsett Pond is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, mercury, nuisance exotic species, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
No clarity data. Chlorophyll-a 13 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 µg/L | Poor |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~39 ft est. |
| Average Depth | ~12 ft est. |
| 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 Monponsett Pond.
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.
Recreation & Access
- Monponsett PondPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Monponsett Pond
Water Quality Trend: ↑ Improving
Based on 8 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Chlorophyll-a | ↑ Improving | -4.01 µg/L/yr | 8 |
EPA Impairment Status
Monponsett Pond is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MA62218 · Official waterbody report · Matched by proximity (0.3 km)
County Ranking
Ranked #9 of 12 lakes in Plymouth County
Nearby Lakes in Plymouth County
Frequently asked questions about Monponsett Pond
Where is Monponsett Pond?
- Monponsett Pond is a lake in Plymouth County, Massachusetts. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Monponsett Pond?
- Monponsett Pond in Plymouth County, Massachusetts has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 13 µg/L.
Is Monponsett Pond safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Monponsett Pond is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, mercury, nuisance exotic species, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
How deep is Monponsett Pond?
- No published bathymetric survey covers Monponsett Pond, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 39 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Monponsett Pond?
- Monponsett Pond has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Monponsett Pond. Public access is listed as yes.
Explore Monponsett Pond across LakeQuality
Species activity outlook by water temperature and season
Where to stay at Massachusetts's top lakes, each with its grade
High nutrients, frequent algae, reduced clarity
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Other Grade D Lakes in Massachusetts
Eutrophic Lakes in Massachusetts
Where this data comes from
56 measurements from 4 monitoring stations, 2012–2019. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Massachusetts Department of Environmental Protection (MassDEP)
MASSDEP56 samples · 2012–2019
Analytical methods
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
Monitoring station identifiers (4)
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)
Named boat-access points from the USGS National Boat Ramps inventory