Threecornered, Threemile, and Webber are interlinked ponds in eastern Kennebec County. Together, their surrounding land covers about 22.5 square miles of countryside, featuring hills, wetlands, and streams. Water flows from Threecornered through Threemile and into Webber Pond, eventually reaching the Kennebec River.

The three ponds are vital community resources offering numerous recreational activities like boating, swimming, and fishing. Each pond has public access points:

• Webber features a public boat launch, campground, and nearby golf facility

• Threemile has a public boat launch

• Threecornered contains the Bicentennial Nature Park for Augusta residents

The ponds contribute to the local economy through tourism and property taxes. In 1997, the Maine Department of Marine Resources began stocking sea-run alewives in Webber Pond, where they are harvested for lobster bait and generate revenue for the Town of Vassalboro.

The water quality in Webber and Threemile ponds has been declining in recent years, with both experiencing harmful algal blooms since 2020, particularly during late summer months. These blooms can produce toxins that are dangerous to people, pets, and wildlife. While Threecornered Pond has better water quality, there isn't enough consistent data to track long-term trends.

The algal blooms have serious impacts on the community:

• Make swimming, boating, and fishing unsafe during bloom periods

• Can produce airborne toxins that spread beyond the water

• Can accumulate in fish and mussels, affecting both wildlife and people who eat them

• May last for three weeks or longer

• Risk lowering property values and hurting the local economy

Scientists and community members are working to better understand what's causing these blooms and find ways to prevent them. The issues are particularly concerning because they affect not just recreational activities, but also the health and safety of residents and their pets.

A Tri-Watershed-based Plan (WBP) including all three ponds needs to be developed in order to apply for the funding necessary to address water quality issues. In order to create this plan, the following steps need to be taken.

• 2 years of water and plankton testing

• Direct watershed surveys of all 3 ponds

• Sediment sampling and analysis

• Data analyses and modeling

• Prioritizing of issues and analysis of remediation options

• Development of a written plan summarizing results, issues, and recommendations.

So far, we have completed year 1 of water and plankton sampling. This year, we will focus on year 2 of this water and plankton testing, as well as direct watershed surveys of all 3 ponds. Following each year of sampling, the results will be analyzed. 2024 data is being analyzed at this time.