Buffers are an important concept in acid-base chemistry. A buffer is an aqueous solution that has a highly stable pH. If you add acid or base to a buffered solution, its pH will not change significantly. Also, adding water to a buffer or allowing water to evaporate will not change the pH of a buffer.
Similarly, in ecosystems, a riparian buffer, (otherwise known as the strip of forest that runs adjacent to our streams and rivers) neutralizes many of the “acids” or “bases” coming of the land into the river. These stream buffers filter stormwater runoff before it enters the stream. The vegetation within the buffer absorbs the excess nutrients that enter our waters and cause algae blooms and fish kills. The outer reaches of the buffer (the most landward sections) slow and spread out the flow of water coming off the land. Slowing down the rainwater runoff traps the sediments and the attached pollutants and helps it infiltrate into the ground rather than flow across it. This infiltration, in turn, allows the vegetation within the inner reaches (closest to the stream) to absorb the nutrients.
It’s free and natural stream protection. It requires no investment, no engineers, no construction, just preservation of a 50 ft strip of land. (Well, really a 30 ft. strip of land, as the outer 20 ft. of the buffer can be maintained as yard and utilized for many uses.)
North Carolina holds stewardship of the second largest estuarine complex in the lower 48 states (the Albemarle-Pamlico Estuary) and buffers are a critical part of maintaining the health and balance of this extremely important resource. The critical importance of sustaining the estuarine system was reflected in its Congressional designation as an “Estuary of National Significance” in 1987.
In addition to their nutrient and sediment removal functions, buffers just so happen to do a lot of other great things–even though these other reasons are not really why they were established in 1997:
• Along rivers and streams, the roots of the vegetation within the buffer stabilize the streambank.
• Along estuaries and large eastern rivers, they dampen wave actions and absorb floodwaters.
• The buffers along rivers and streams keep water temps cool from their shade, and provide both structure(fallen limbs) and food to the stream ecosystem.
• the beauty of healthy, vegetated floodplains is economically valuable – attracting and supporting water-based recreation and ecotourism, and increasing the market value of nearby properties.
The adoption of the buffer rules was considered a great collaborative success and was backed by science, stakeholders, and regulators. Now, nearly 20 years later, however, our representatives in Raleigh are set to make changes to where the rules apply that essentially eliminate buffers, without considering the science and without stakeholder input.
Interestingly, it should be noted that these buffers are also a key component of the federal requirements to control water pollution imposed on North Carolina. Without the use of buffers, the mandated reductions will have to come from other sources, like agriculture and municipalities discharges.
Toxic microcystin bacteria float, along with a dead fish, on the surface of this lake. Credit: Oregon State University
Sadly, this is just one of many bad environmental bills rolling through our legislative building this year. For a helpful and disturbing summary, check out this recent article in the Charlotte Observer.
The bottom line: Unless elected officials come to their senses and soon, North Carolinians should prepare to say “bye, bye” to their streamside buffers and “hello” to degraded estuaries, more algae blooms, and fish kills.
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