The 5 clearest lakes in New Hampshire

At Secondwind, we help homeowners, businesses and communities throughout New Hampshire manage the quality and safety of their drinking water. During our more than three decades of service, we’ve also become an expert on NH’s water landscape. The lakes in New Hampshire are some of the clearest in the country and this post outlines where to find the crystal-clear lakes in the state. 

There are nearly 1,000 lovely lakes in NH, making it a challenge to visit them all (but here’s a list in case you want to try). Whether you live here or are planning a visit this year, here is a guide to the cleanest and clearest lakes in New Hampshire.

What makes New Hampshire’s lakes so clear and clean?

Before we jump to the guide, let’s discuss why our state’s lakes are so clear. According to Christine Fletcher, President and Founder of Secondwind Water Systems, there are three key or “low” reasons behind the remarkable clarity of New Hampshire’s lakes:

• Low turbidity: Turbidity, or the measure of loose particles in a liquid, is a key indicator of water quality. NH lakes have fewer floating particles than many lakes in the country, giving them a clean, clear appearance. 
• Low phosphorus and algae levels: Phosphorus is an essential element for plant life, but when there’s too much of it, it causes an excessive growth of large plants and algae. This results in decreased levels of dissolved oxygen a.k.a. Eutrophication. Excessive algae in bodies of water can be harmful to people and animals. 
• The pH levels: A measure of how acidic/basic water is, pH affects organisms living in water. Changing pH levels in a stream can be an indicator of increasing pollution or some other environmental factor. The pH of surface water is also affected by the precipitation of acidic compounds, such as sulfuric or nitric acid, released into the atmosphere as a result of industrial processes. The range goes from 0 – 14, with 7 being neutral. Most lake and pond organisms prefer pH levels of 6.5 to 9.

New Hampshire’s Department of Environmental Services recognizes the value of our state’s lakes and has several programs in place to help preserve and protect this resource, including monitoring exotic species and testing acid, mercury and cyanobacteria levels. 

Other volunteer-driven organizations, including the New Hampshire Lakes Association, also keep our lakes healthy and safe for future generations.

Clearest Lakes in New Hampshire

According to New Hampshire Department of Environmental Services (NHDES) test reports, the overall quality of our state’s 165,000 acres of lakes and ponds is very good. Most lakes are categorized as having “excellent” or “good” water quality. Even the National Secchi Dip-in has repeatedly ranked New Hampshire as one of the top five states in the country for water clarity. 

NH offers two statewide programs that utilize volunteers collecting data on lake health:

• New Hampshire Department of Environmental Services Volunteer Lake Assessment Program
• University of New Hampshire Cooperative Extension Lay Lakes Monitoring Program

Here are our state’s five clearest lakes, according to the NHDES:

Nebanusit Lake: Located between the towns of Nelson and Hancock, this 718-acre lake is classified as a cold-water fishery. It is perfect for boating, kayaking and taking a refreshing swim. Boating southeast there is conservation land halfway down the shore. Granite extends into the water where you can picnic or swim.

Lake Winnipesaukee: New Hampshire’s largest lake, Winnipesaukee is roughly 21 miles long and covers about 70 square miles. People have been flocking to Lake Winnipesaukee every summer for generations, enjoying boating, canoeing, fishing and swimming on its many beaches. Don’t be surprised to see water skiing and other water sports on the vast lake. Springs and melting snow annually add clean, clear water to the lake. Visit here for information about this lake’s many activities.

Merrymeeting Lake: Located in New Durham, this 1,233-acre recreational lake is moderately- to heavily-developed. Locals speak highly of great year-round fishing. Kayaking is popular in warmer months. Although beautiful, its undeveloped areas are not easily accessible by road.

Spofford Lake: This 732-acre lake is located in Chesterfield. Fishing and motor boating are popular recreational activities here. There are ample public beaches, too. In 2005, the NH Fish and Game Department named Spofford Lake the cleanest lake in New Hampshire. The words “crystal” and “clear” are often associated with Spofford. 

Lake Sunapee: Located in Sullivan and Merrimack Counties, Lake Sunapee is roughly 8.1 miles long and covers 6.5 square miles. If you’re seeking tranquility, there are some quieter spots on the beaches to enjoy the calm waters. For information about the region’s many activities, visit the Lake Sunapee Chamber of Commerce.

Clearly, you love your water clean – and clear. But how clean is your water at home? We’re happy to visit you and provide a free water analysis. We think of ourselves as experts in New Hampshire water, as we’ve been successfully treating water for homes and businesses for more than 30 years. Call us at 603-641-5767 if you have any questions about residential or business water quality. 

And, remember to do your part to help keep New Hampshire’s lakes clean and clear when you visit!

Secondwind Cares About Your Water

At Secondwind Water Systems, we know New Hampshire water—we’ve been treating it for more than 30 years. If you have questions about your home’s water quality, give us a call at 603-641-5767.  We’re happy to come out and provide a free water analysis.