Buffers and Setback
The health of streams and rivers depends to a great extent on the lands that surround them. Over the last two decades, researchers have shown that preserving naturally vegetated corridors along streams can “buffer” them from the degrading effects of nonpoint source pollution while reducing the impact of floods, providing habitat for wildlife, and offering recreational benefits to people. Protected stream and river corridors or “riparian buffers” are now widely advocated by a range of federal, state, and local agencies for protecting water quality on agricultural, forestry, residential, and other lands.
Riparian buffers are the single most effective protection for our water resources in the upper Merrimack River watershed. These strips of grass, shrubs, and trees along the banks of rivers, streams, and ponds filter polluted runoff and provide a transition zone between water and human land use. Buffers are also complex ecosystems that provide habitat and improve the stream and river communities they shelter.
Natural riparian buffers have been lost in many places over the years. Restoring them will be an important step forward for water quality, stream and riverbank stability, wildlife, and aesthetics in the upper Merrimack River watershed. Landowners, town road agents, local governments, farmers, and conservation organizations can all help protect and restore the riparian buffers which in turn protect and restore the quality of our streams and our river.
Establishing the appropriate width for riparian buffers can vary depending upon the availability of land and what primary function the buffer is to provide. There isn’t one generic buffer width that will keep the water clean, stabilize the banks, protect fish and wildlife, and satisfy human demands on the land. A minimum riparian buffer width of 50’ from the top of the bank will provide bank stabilization, support fisheries habitat, limited sediment control, and nutrient removal with very little wildlife habitat and no flood control capacity. There is an increasing benefit for every foot of buffer width established. An optimal condition in the upper Merrimack River watershed would be one with 300’ riparian buffers along all stream and river banks to provide the maximum amount of benefit for pollution uptake, sediment control, flood attenuation, bank stabilization, fisheries habitat, and wildlife habitat.
GOAL 14: Continuous and functional buffers along the upper Merrimack and its tributaries are maintained and enhanced. OBJECTIVE: BS-1 – By the mid-2008, all current setback and buffer requirements imposed at the state or local level in the upper Merrimack municipalities will be inventoried.
Develop a GIS map and data table showing current setback and buffer requirements throughout the corridor based on local and state regulations.
OBJECTIVE: BS-2 – By the end of 2008, recommendations will be formed and presented to UMRLAC municipalities to improve the effectiveness of their ordinances based on the existing conditions and the available scientific information that has been developed and adopted within the New England region.
- Update GIS map and data table to show recommended or proposed buffer and setback requirements based on proposed NHDES Shoreland Protection Rules requirements and other relevant data such as that contained in the Wildlife Action Plan to protect key habitat areas.
- Present updated buffer and setback information to UMRLAC municipalities at special meetings or in conjunction with planning board, zoning board of adjustment, or conservation commission meetings.
OBJECTIVE: BS-3 – By end of 2008, existing outreach materials will be identified and distributed to assist citizens and landowners in recognizing the importance and effectiveness of setbacks and vegetated buffers.
Develop a brochure or pamphlet to highlight and educate residents and landowners on the benefits of the recommended buffer and setback requirements. Work with NHDES Watershed Management Bureau to develop PowerPoint presentation on the topic of vegetated buffers, developing buffer ordinances, and implementing buffer ordinances.
GOAL 15: Continuous and functional buffers are established along those areas of the upper Merrimack and its tributaries where they don’t exist. Setbacks along the upper Merrimack and its tributaries are established or maintained to ensure stream bank and habitat integrity.
OBJECTIVE: BS-4 – By mid-2008, areas are identified for improving and enhancing functional buffers in key locations.
Provide local planning boards and conservation committees a list with accompanying maps of areas that are in need of improvement of buffers along the river. Utilize the updated GIS map information to overlay existing, functional buffers with information contained in the Wildlife Action Plan and the NHDES 303(d) List of Impaired Waters for the upper Merrimack and its tributaries. Prioritize areas within the upper Merrimack watershed for improvement or enhancement of existing, functional buffers.
OBJECTIVE: BS-5 – From 2007-2011, an incentive-based approach will be developed to allow landowners to maintain their existing uses in buffer areas and encourage a no-net decrease in the buffer area when the expansions of uses are proposed within that area.
- Investigate other incentive-based approaches to buffer establishment and protection in New England and develop a strategy for the upper Merrimack and its tributaries.
- Work with UMRLAC municipalities to draft incentives that would allow developers the same number of lots outside the buffer as they would in a conventional layout, considering the amount of land that is high, dry, and flood-free.
- Work with UMRLAC municipalities to develop low-density bonuses for land conserving designs, and density disincentives to discourage land consuming layouts.
OBJECTIVE: BS-6 – By early 2009, funding sources will be identified to assist landowners in implementing or enhancing buffer areas along key stream reaches.
- Research and develop a funding source “menu” for UMRLAC that identifies and prioritizes funding programs applicable for buffer establishment, maintenance, and restoration.
- Secure funding and implement a pilot project that educates the public about the value of riparian buffers, delineates existing, protected, functional buffers in a project area, and permanently marks the buffer boundaries for developers and the public.