Nitrogen, phosphorus, and other nutrients can degrade water quality and promote the growth of nuisance aquatic plants and degrade overall water quality in a lake. Although we no longer have septic systems leaching nutrients into Halfmoon Lake, any fertilizer that residents apply to their lawn end up in the lake and promote the growth of nuisance plants and algae. Natural shorelines, buffer strips, rain gardens, and alternatives to mowed grass decrease the amount of nutrients entering the lake and degrading water quality.

Invasive species like zebra mussels, purple loosestrife, and starry stonewort outcompete native species and impact the way that we appreciate our lake. Halfmoon Lake has already been invaded by many invasive species, but it is still in relatively good shape. Cleaning boats and trailers before launching into the lake, limiting the transport of plants among the lakes in our chain, and removing established invasive species before they establish and reproduce can help reduce spread. Populations of invasive species can be managed through a suite of treatments. Guidance on how to manage invasive species is available through the HLCA, Huron River Watershed Council, or a suite of other resources.

Energy from lake waves can easily wash away unprotected shoreline (e.g., beaches, wetlands) and cause damage to property and habitat. Waves from boats (especially wake boats and boats driving close to shore) cause extra damage during periods of high water levels. Shorelines in front of homes can be protected with natural materials (e.g., rocks) to provide both protection from erosion and habitat for fish and wildife.

Oil and gas from boat motors can drip into the lake and contaminate water used by people, fish, and wildlife. It is critical to maintain engines and perform any maintenance on land and limit the opportunity for contaminants to get into the lake.