An Overview of New Hampshire's Rivers and Lakes

Largest and Famous Water Features

New Hampshire is home to several well-known rivers and lakes. The Connecticut River is the state's longest river, while Lake Winnipesaukee is the largest and most famous lake, renowned for its scenic beauty. The Merrimack River, another significant waterway, flows through the state's central region. Other notable water features include the Androscoggin River and Squam Lake. These water bodies are vital to both recreation and local ecosystems.

Water Sources of New Hampshire's Rivers and Lakes

The rivers, lakes, and streams in New Hampshire are primarily fed by local mountain snowmelt, particularly from the White Mountains. These sources are crucial for replenishing water systems in the state during springtime. However, some rivers like the Connecticut receive additional water from distant sources outside the state, such as Vermont and Canada. Rainfall is another significant contributor to New Hampshire’s water supply. Seasonal changes also affect water levels in lakes and streams across the region.

Types of Rivers and Inland Waterways

New Hampshire boasts a variety of river types, including perennial rivers like the Connecticut and Merrimack. Tributary rivers, such as the Pemigewasset and Souhegan, feed larger systems, while there are no exotic or distributary rivers in the state. Man-made rivers or aqueducts are rare, but the state has a network of small canals, such as the Amoskeag Canal, mainly used historically. Rapids can be found in places like the Saco River, and the state also has winding rivers like the Contoocook with its many bends.

Lake Types in New Hampshire

New Hampshire's lakes are predominantly glacial in origin, with Lake Winnipesaukee and Squam Lake being prime examples of glacial lakes formed during the last Ice Age. There are also several small tarns, or cirque lakes, in the White Mountains region. Fluvial lakes, formed by river processes, are less common, but some can be found near river bends. The state also has anthropogenic lakes, such as Lake Franklin Pierce, created by damming rivers for various purposes.

River Flow Directions

Rivers in New Hampshire predominantly run in a north-south direction, with the Connecticut River being a prime example as it flows southward along the state's western border. The Merrimack River also flows south before turning eastward toward the ocean. East-west flowing rivers are less common but include tributaries like the Swift River, which runs eastward before merging with larger water systems. The White Mountains influence the flow patterns of many rivers in the state.

Natural vs. Manmade Lakes

While many of New Hampshire's lakes are natural, several are man-made reservoirs created by damming rivers for hydroelectric power and flood control. Lake Francis and Lake Franklin Pierce are examples of man-made lakes, constructed by state and federal agencies such as the U.S. Army Corps of Engineers. Most of the natural lakes, like Lake Winnipesaukee, have been shaped over millennia by natural geological processes. These lakes support both recreational and commercial activities.

Rivers for Transportation

The rivers in New Hampshire are not heavily used for major transportation due to their relatively short lengths and the state's geography. The Connecticut River does support limited commercial transport, but it is not a significant route for large cargo shipments. The Merrimack River was historically important for transporting goods, but today it is primarily used for recreational boating. Overall, most water-based transportation in the state is focused on recreational rather than commercial use.

Dams and Their Purposes

New Hampshire has many dams, primarily used for hydroelectric power generation, flood control, and recreation. The largest dam is the Moore Reservoir Dam on the Connecticut River, which generates power for the region. Other dams, like the Franklin Falls Dam, provide flood protection for surrounding communities. Many smaller dams create reservoirs that are used for recreational activities, such as boating and fishing, across the state.

Recreational Uses of Water Features

Many of New Hampshire’s lakes, reservoirs, and rivers are popular spots for recreational activities. Lake Winnipesaukee is famous for boating, jet skiing, and fishing, while the Saco River is a favorite for kayaking and tubing. The Connecticut River also supports a variety of recreational activities such as paddleboarding and fishing. House boating is popular on larger lakes like Squam Lake, attracting tourists and locals alike during the summer months.

Agricultural Support from Water Features

The rivers and lakes in New Hampshire play a vital role in supporting agriculture, particularly in the Connecticut River Valley. The fertile soil along the Connecticut River supports the state's dairy farms and crop production, while smaller rivers provide necessary irrigation. The Merrimack River also contributes to farming communities, especially those growing fruits and vegetables. The state’s reservoirs help ensure a steady water supply during dry periods.

Pollution Concerns of Rivers and Lakes

Some of New Hampshire’s rivers and lakes have faced pollution challenges in the past, primarily due to industrial waste and runoff. The Merrimack River, for instance, was once heavily polluted by textile mills and other factories along its banks. Over the years, significant efforts have been made to clean up these water bodies, and today many of the rivers are safe for recreational use. However, periodic issues with stormwater runoff and agricultural pollutants still occur in certain regions.