UPDATE: August 2018
****Report just released! Tremendous value of natural riparian buffers documented!****
A stream is not just the water that flows through a channel. A stream includes its bed, its banks, and the lands that run along its length. The land along our streams and rivers is an essential and living part of the stream ecosystem. To be healthy, a stream needs its adjacent lands to be covered with healthy, varied and native vegetation.
Vegetated buffers provide a living cushion between our upland land uses and our living streams providing important protections to both the stream and our human communities. Vegetated buffers help protect our communities from non-natural flooding – the soils and vegetation soak up and hold floodwaters, gently releasing them after the storm has passed. This flood protection reduces flood damages in our communities as well as minimizing the need for costly emergency response. Vegetated buffers filter out pollution, that washed from the land as well as that already in the water thereby protecting our drinking water as well as our special places for boating, swimming, fishing and birding. Vegetated buffers protect and improve our local economies – they increase the market value and marketability of nearby homes; they support the qualities needed to sustain a healthy ecotourism industry, and they provide the clean and fresh water needed to support a variety of industry and waterside needs. Vegetated buffers help encourage infiltration of rainfall and runoff helping to keep our underground aquifers flowing and available during times of drought. Vegetated buffers protect public and private lands from erosion. And, vegetated buffers provide essential habitat, in stream and on the land, for aquatic life, birds, wildlife, amphibians and reptiles.
When we devegetate and fill our riparian buffer areas we not only destroy their ability to provide these community benefits, but the opposite harmful reaction results --- rather than flood storage we have increased flooding; rather than aquifer recharge we have increased drought; rather than healthy streamside lands and habitats we have erosion and degraded ecosystems; and so on.
It is essential we protect our vegetated buffers for the health of our streams and our communities.
How Much of a Buffer Should Be Protected?
In general, riparian buffers should be as wide as possible. The bigger the buffer the more pollution it can filter, the better habitat it can provide, the more water it can absorb, hold and infiltrate.
A wealth of new science focused on buffers is taking place. These studies are telling us that a minimum 100 foot buffer is best for protecting water quality, for preventing and removing pollution, and for protecting habitats in the stream and on the land. In a number of instances buffers ranging from 300 to 1000 feet are being recommended, or even required, in order to provide the greatest level of protection our natural waterways and habitats need. When focused on bird life and wildlife the buffer minimum is tending towards 300 feet or greater. In this case too, bigger is definitely better – providing better quality habitat and needed migration paths for a variety of wildlife.
Also very important to the effective functioning of a riparian buffer is the quality and mix of vegetation. Characteristics such as species diversity, vegetation type, physical condition and maturity all affect the ability of the buffer to do its job. The forested buffer which includes a mix of plants, shrubs, and trees can work on steep slopes, where other vegetation, especially grass, and other BMPs may be difficult to install and maintain.
Delaware Riverkeeper Network is working to get requirements at the state and regional level that ensure protective buffers for all streams in the watershed. We were leaders on the successful effort to get 300 foot buffer requirements for C-1 streams in NJ and 150 foot buffers on exceptional value and high quality streams in Pennsylvania.