Stockbridge Bowl is a eutrophic lake with a surface area of 398 acres and a maximum depth of 52 feet. The lake is a highly used recreational resource and one of the most visited lakes in Western Massachusetts. This ‘Great Pond’ had not been studied in detail for 30 years.  


The lake is impacted by aquatic plant growth which is dominated by Eurasian Milfoil, and the lake is prone to developing harmful algal blooms (HABs).


Partnered with Dr. Robert Kortmann of Ecosystem Consulting Services (ECS), the GZA/ECS team designed and conducted a monitoring program to determine changes to the lake over the past 30 years; identify contributing and important factors of cyanobacterial/algal bloom to anticipate bloom formation; and recommend future management strategies. The GZA/ECS team trained and mentored the town’s staff to assist with monitoring the lake and become the primary samplers in future lake monitoring efforts. Sampling round results were reported monthly to the town to provide feedback and develop ongoing lake management strategies.


Comparing current limnological data with those from 30 years ago revealed that the lake status had remained eutrophic. Indeed, due in part to improvements in the watershed, several water quality parameters were better in 2020 than in 1990. The study identified several factors that influence cyanobacteria/algae type and abundance, preferred depth within the water column for parameters such as internal nutrient loading concentrations, the dominance of the calcium carbonate system, and the thermal structure of the lake. Continued lake monitoring and preparation of a lake management plan will help to fine tune the ability to forecast future bloom formation.