New Hampshire’s Headwater Streams
When we think about nature in New Hampshire, it’s easy to imagine the towering peaks of the White Mountains or the sparkling waters of Lake Winnipesaukee. But there are resources much smaller and less obvious – yet equally important – that play a crucial role in keeping the state’s ecosystems healthy: headwater streams. These tiny streams that trickle down from higher elevations might not get the same attention as larger rivers, but they’re essential to New Hampshire’s ecosystems and wildlife.
What are Headwater Streams?
Headwater streams are small, often overlooked tributaries that feed into larger rivers and lakes. Found in the highest end of a watershed, headwater streams play a crucial role in supporting wildlife in New Hampshire by providing essential habitat for a variety of species and helping to retain high water quality downstream. However, some are so small that they don’t show up on maps. If a river network is the circulatory system of the landscape, headwater streams are the small capillaries that fan into the larger veins and arteries. Headwater streams can start as small forested wetlands, beaver impoundments, or cascading mountain streams, varying according to the topography and geology of the surrounding landscape.
Why do they matter for wildlife?
Depending on the water flow, river bottom material, plants present, and timing of water presence, these streams will support various wildlife species. For example, Mountain streams tend to have large rocks, steep grades, and flash floods. Stream salamanders, brook trout, and certain aquatic invertebrates are well adapted to these dynamic habitats. On the other hand, valley streams tend to be slow-moving and surrounded by wetland plants and shrubs. Beaver activity creates a patchwork of wetlands around the streams, including shrub swamps, wet meadows, and ponds, which draw in wildlife including ducks, geese, turtles, amphibians, and fish.
Mountain headwater streams tend to have large rocks, steep grades, and flash floods, while valley streams tend to be slow-moving and surrounded by wetland plants and shrubs.
Headwater streams are places where forest and stream habitats converge, leading to high densities of insects around the streams. Stoneflies, mayflies, and dragonflies, whose larvae live underwater, are found alongside upland insects such as moths, beetles, and grasshoppers. This concentration of food attracts predators from the surrounding forest including northern long-eared bat, red-shouldered hawk, raccoon and ribbon snake.
These small streams also have a large impact on the health and integrity of major rivers downstream. They help to remove excess nutrients, such as nitrogen, from a watershed, helping ensure cleaner water downstream. Wood in the small, upriver streams traps leaves and other nitrogen sources, preventing them from accumulating in the lower reaches of the river.
Eastern brook trout depend on clean, cold water and are well-adapted to living in small streams where they may live year-round, feeding on both upland and aquatic insects. They may also travel over 20 miles from larger rivers to headwater streams during the fall spawning season or, if the streams have enough water, to find a cool refuge during the summer months. New Hampshire remains a stronghold for brook trout in the Eastern United States but, even here, populations are declining.
Eastern Brook Trout
How can you support headwater streams?
Despite their ecological value, headwater streams are often overlooked by conservation efforts and are not covered by some state and federal regulations. Their small size makes them vulnerable to human impacts, particularly those caused by human development like runoff and habitat fragmentation. These and other threats are compounded by the tendency to dismiss small streams because they don’t command the same recreational and aesthetic appeal of larger water bodies, and because they are often considered too small to provide important habitat.
Luckily, there are many steps you can take to protect and conserve headwater streams in New Hampshire.
- Conserving land from development around headwater streams allows for the natural processes that prevent flooding, maintain water quality, quantity, and temperature, recycle nutrients, and provide food and habitat at the source and downstream.
- Incorporating headwater stream protection into town and regional planning through conservation easements and zoning ordinances has lasting benefits by conserving species, protecting water quality and preventing flood damage.
- Avoid the use of fertilizers or pesticides near any stream or wetland habitat. Many pesticides are toxic to aquatic organisms. Excess nutrients from fertilizers pollute water by reducing oxygen levels, killing fish and other species.
- Avoid culverts, drains or ditches that discharge storm water directly into streams, and ensure properly sized and installed stream crossings to maintain functions.
- Timber harvesting around headwater and small streams should maintain enough shade and large trees to maintain stream temperatures, filter run-off, and allow for woody material (dead and dying trees, leaves, branches) to naturally fall into streams.
For more information on Headwater Streams in New Hampshire, including more detailed actions you can take to protect and conserve these important resources, view the Headwater Streams brochure. This brochure is part of the Habitat Stewardship Series, developed with information and strategies from New Hampshire’s Wildlife Action Plan.
