Lake Management Committee

As of 2024, what was formerly the environmental committee was split into the Forest Stewardship Committee (FSC) and the Lake Management Committee (LMC).

The goal of the LMC is to work with the MRI Board and the Mount Riga Community to ensure the health and longevity of our lakes. For more than a decade we have worked with Northeast Aquatic Resources (NEAR) to do lake testing and reports, which are available below. As of 2025 we have transitioned to Applied Watershed Sciences (AWS), led by Hillary Kenyon, who will continue to work with us to monitor and provide recommendations for our lakes.

Broadly, the concerns about lake health can be divided into water quality and invasives.

Water Quality

Probably the most obvious indicator of lake quality is simply how clear the lake is. In the 1980s, Riga lakes were classified as pristine, as clear as any in New England. Clarity can be measured using a Secchi disc, a black and white metallic reflector that is lowered into the lake until it can’t be seen, or it hits the bottom.

In 1986, the earliest date from which we have monthly data, the Secchi discs were visible all the way to the bottom of the upper lake, more than 30 feet down, during each month of the summer. However, over the years the clarity has markedly declined and has been particularly evident in the last few years. The last time a Secchi disc was visible at the bottom of the Upper Lake was in November of 2020. The summer of 2023 was a particularly alarming year, with visibility below 6 feet during the later part of the summer. The summer of 2024 showed some improvement, but the long-term trend is towards decreased clarity.

This graph shows the Secchi disc depths over the years for North Riga (upper) lake:

Clarity of the lake can be affected by several things, including debris that is stirred up during rainstorms. This likely caused some of the marked decreases in clarity in 2023, as it was one of the wettest summers on record. However, clarity is also affected by the trophic level of the lake – the level of nutrients that feed plant growth. Broadly speaking the trophic level of a lake can be divided into oligotrophic (nutrient poor, minimal algae, very clear), mesotrophic (moderate level of nutrients and some plants), and eutrophic (high levels of nutrients and murky water). Back in the 1980s our lakes were clearly oligotrophic, but we are now in danger of moving towards more trophic states.

Phosphorous is one of the primary nutrients that increases the trophic level of the lake. Phosphorous can come from the natural environment, from human inputs (waste and soap), and can also be exacerbated when a process called internal loading occurs – a cycle that releases phosphorous from lake sediment when oxygen levels become low, a condition that we have seen more of recently.

While some of the changes in clarity and trophic levels of the lake may be part of the natural aging process and natural impacts that are beyond our control, it is essential that we do everything we can to minimize human impact.

What can I do to help with water quality?

The main thing you and your camp can do to limit human impact on the lakes is to minimize the introduction of outside contaminants, particularly anything with phosphorous. Ideally no soaps or detergents should be allowed to flow into or used in the lakes. Even the list of recommended products should be limited as much as possible. Consider using clothing for sun protection as opposed to sunscreen. Ensure that any septic systems, outhouses, or other drainage systems are not contributing waste into the lake. Do not use fertilizer anywhere near the lake. See our informational brochure on lake health.

Next steps: over the next couple of years the LMC hopes to work with AWS, the MRI Board, and the community to get a better understanding of what human impacts are currently occurring, which may take the form of surveys and assessments of camp use and practices. More to come!

Invasives – Hydrilla

Invasive species are non-native plants that may have the potential to significantly impact the quality of, and our ability to enjoy, our lakes. Over the years we have worried about Eurasian Millfoil, Zebra Mussels, and others. However, in June of 2023 the nearby Twin Lakes discovered the presence of Hydrilla verticillata, an extremely aggressive and fast-growing species that had previously only been found in the Connecticut River.

Once Hydrilla is established it can be exceedingly hard, if not impossible, to eradicate. In October of 2024, the leader of the Twin Lakes Association discussed this battle, which will likely cost them over a million dollars in the next few years.

Obviously, the best way to avoid a costly battle against Hydrilla is to never have it in our lakes in the first place. This requires vigilance, as even a small strand attached to a boat or flotation device could introduce it.

The other priority is early detection, as it may be possible to mitigate it or eliminate it if it is detected early enough. If you see something say something!

What can I do to help with invasives?

Do not allow Hydrilla to be introduced. Never use off mountain watercraft or flotation devices in our lakes. Never use live bait if fishing. Consider maintaining a mountain-only swimsuit to avoid cross contamination. Keep an eye out for it and contact someone if you think you see it. See our informational brochure on hydrilla. Speak up! If you see someone doing something that might be harmful to our lakes share information regarding our aquatic invasive prevention efforts.

Citizen Testing

The LMC relies heavily on our volunteers to assist with testing. These initiatives have been led by Helen Antoshak and Maggie Moore and we are very thankful for their many hours and efforts over the years! If you would like to be involved with lake testing, please reach out to us!