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LakeQuality

A eutrophic lake is a productive ecosystem with the trade-offs that come with productivity: more food at the base of the food web, more clarity reduction by mid-summer, more dissolved-oxygen variability near the bottom. 17 Pennsylvania lakes register as eutrophic. Only 6% are deep — eutrophy correlates with shallowness, agricultural watersheds, and the kind of nutrient-input history that takes decades to shift.

Eutrophic lakes typically carry higher phosphorus and chlorophyll-a readings. The same nutrient richness that defines the trophic class shows up in those numbers.

#LakeCountyClarityDepthTSI
1Lake NockamixonBucks4.8 ft-55
2Promised Land LakePike---
3Waynewood LakeWayne---
4Laurel LakeWayne-24.9 ft-
5Alder Marsh PondWayne---
6Kettle Creek LakeClinton-31 ft-
7Ontelaunee LakeBerks---
8Shenango River LakeMercer---
9Fords LakeLackawanna---
10Elmhurst ReservoirLackawanna---
11Pinchot LakeYork-30.2 ft-
12Green Lane ReservoirMontgomery---
13Allegheny ReservoirWarren-131.2 ft-
14Lake ChillisquaqueMontour-40 ft-
15Peace Valley ReservoirBucks-40 ft-
16Dutch Fork LakeWashington-25 ft-
17Lake CanadohtaCrawford-13.6 ft-

Source: EPA National Aquatic Resource Surveys, 2026.