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Buffer strips are trees, shrubs, and groundcover that catch sediment and nonpoint source pollution before they reach the lake. Environmental professionals ...
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BUFFER HANDBOOK
Acknowledgements
This handbook was published with the help of the Clean Water Act, Section 319 funds, under a grant awarded to the Androscoggin Valley Soil & Water Conservation District, by the Maine Department of Environmental Protection and the US Environmental Protection Agency, Boston Regional Office. Special thanks to Kathy Hoppe and Karen Hahnel, MDEP, for their insightful comments, patience, and unfailing good humor. Rachel Gallant, AmeriCorps mem- ber at the MDEP, did the layout and additional editing.
Most of the graphics used throughout the text were developed by the University of Wis- consin-Extension, in cooperation with the Wisconsin Department of Natural Resources. Brian Kent drew the shoreland zoning picture on page 16, and John Luoma drew the buffer picture on page 18. Photographs were provided by Scott Williams, Lake & Watershed Resource Man- agement Associates; Lisa Krall, Natural Resources Conservation Service, and Phoebe Hardesty, AVSWCD.
This electronic version is a 2011 recreation of the published manual. While some of the graphics are different in some sections and minor modifications, such as updating contact in- formation, were made, the base information is essentially the same as the manual created in 1998 and reprinted in 2001.
Property owners have a view of the lake while maintaining an effec- tive vegetated buffer of trees, shrubs, and undisturbed ground layer.
T H E B U F F E R H A N D B O O K
Maine's lakes and streams are among our state’s greatest natural assets. As resi- dents, we take for granted the availability of clean surface waters for fishing, swimming, and escaping from the hubbub of our daily lives. In fact, more and more people are choosing to live on or near lakes.
How do population increases in the watershed (the land whose surface water drains into the lake) put pressure on water quality? As land becomes more developed, trees and shrubs are removed to make room for our homes, businesses, and roads. This causes an in- crease in the amount of impervious area, which results in greater amounts of storm water run- off. The runoff sweeps the watershed of loose sediment and debris (called nonpoint source pollution, or NPS) and carries the pollution to the lake.
Over time, development anywhere within the watershed, whether along a stream or lake, combined with NPS pollution, can have serious effects on the quality of our lakes and streams. Values of shorefront properties are dependant on healthy waters, as are recreational opportunities such as camping, fishing, and boating. Visual signs of NPS pollution include in- creased weed growth along lake shorelines, reduced water clarity, algal blooms, sediment del- tas, and altered wildlife habitats. Since the values of shorefront properties are dependent on healthy waters, it is vital to control NPS pollution.
Vegetated buffers, or areas of vegetation situated between the built environment and the water, trap sediments, excess nutrients, and other pollutants, prevent erosion, and help to stabilize sloped areas and the shoreline.
The purpose of this handbook is to help you get started on planting your shoreline. There are many options for design and plant materials, and we've included information to help you with your planning. Although the primary focus of this handbook is lakefront areas, the same principles apply to all waterfronts throughout the watershed.
Remember:Remember:Remember:Remember: clean water starts with you!clean water starts with you!clean water starts with you!clean water starts with you!
How do vegetated buffers work?
♦ The tree and shrub canopy intercepts raindrops and reduces their impact on the soil.
♦ Leaf surfaces collect rain and allow for evaporation.
♦ Low herbaceous plants and the duff layer filter sediment and pollutants from runoff.
♦ Root systems hold soil in place and absorb water and nutrients.
♦ An uneven soil surface (with hummocks and depressions) al- lows rain and snowmelt to puddle and infiltrate.
Lawns alone cannot provide sufficient water quality protection on your shorefront lot. The grasses used in common lawn mixes are shallow-rooted, and while they do protect against surface erosion, they can't provide adequate protection over the long haul. Lawns are best used as part of an overall landscape design, to provide open space for outdoor activities. But, to save yourself maintenance time and to protect water quality, keep lawn areas to a minimum. Avoid use of fertilizers, herbicides, and pesticides; use lime to build a heartier turf. Lime sweetens the soil and makes nutrients available to root systems.
Elements of a good buffer
To be effective, vegetated buffers need to be situated between the lake (or stream or drainage channel carrying water to the lake) and the developed area of your property. Re- member, the purpose of buffers is to slow down runoff so that water and nutrients can filter slowly into the ground.
Buffers should not have straight channels through them, but paths that wind to the waterfront made of stable, nonerodible material. Straight path- ways of bare soil act as conduits for pollutants, and are easily eroded. Uneven ground surfaces, with hummock and depressions, also help to slow down runoff, so that water can filter into the ground. Buffers should be as deep as possible, and span the entire length or width of the developed area you are shielding.
pact of rain and wind, provide shade and habitat, and are long- lived. Their deep root systems absorb water and nutrients while maintaining the topographical structure of the land.
cies, also deflect wind and rain, and are attractive to people and wildlife. Their medium-depth root sys- tems absorb water and nutrients, and hold the soil in place.
matter on the forest floor. This layer acts like a sponge, to absorb water, trap sediment, and prevent erosion. Duff is a host to microorganisms that break down plant material and recycle nutrients.
ers and herbs, slow down surface water flow, absorb nutrients and water, and trap sediment and organic debris. Their many forms are attractive, and their shallow root systems hold the soil in place while protecting the ground surface from erosion.
Buffers supply shade, shelter, and a food source at the water's
edge, ensuring habitat for wildlife that frequent shoreline areas.
♦ Fruits of the redosier dogwood are eaten by ruffed grouse, pheasant, wood duck, and many species of songbirds.
♦ The low, dense growth of the beaked hazelnut is ideal nesting and protective cover for wildlife; squirrels and chipmunks feed on the nuts, while grouse feed on the catkins.
♦ Leaves from trees and shrubs that fall into the water provide food sources for aquatic insects, themselves being food for fish and other small vertebrates.
Buffers are attractive, long-lived, easily
maintained, and can be created at low costs.
Several options exist for buffer designs. A little time spent in planning can have big payoffs later in maintenance requirements. Just think -- less lawn to mow! Choose a plan that fits your lifestyle, and remember that you do not have to complete your buffer in one season.
Shrubs and flowering plants have been added to the natural growth of this buffer.
Preventing erosion saves time and money!Preventing erosion saves time and money!Preventing erosion saves time and money!Preventing erosion saves time and money!
Understanding Your House Lot
T H E B U F F E R H A N D B O O K
To get started, you need to make a careful assessment of your property. The physical characteristics of your present landscape will provide you with a framework for your buffer de- sign. Understanding the character of your lot is vital, so that you can put the right plants in the right places. Careful planning will save you time and money and yield results that will make you proud.
Site characteristics you must consider:
size of your lot and how the buildings and driveway are laid out. If your lot is small or your buildings are set close to the lake, you may not be able to have a 100- or even a 75-foot buffer, but any buffer is better than no buffer. Older camps in particular are set close to the lake. Prior to the Shoreland Zoning law, when we did not understand how to protect our lakes, there was no building set back requirement or a very limited one (for more information on the Shore- land Zoning law, see page 16). Today, as a result of many studies, we understand that build- ing close to a lake or stream significantly increases the pollution load going into the lake. Buff- ers help reduce this pollution load. Since the objective of the buffer is to prevent erosion and filter pollutants, planting buffers up slope of your home or down slope of the road will also help. The goal is always to prevent erosion and intercept water flow before it reaches the lake or stream.
since good soil is the foundation for healthy plants. There must be a good match between the soil and the plants chosen for the buffer. Soil types may vary from place to place on your lot. For example, one section may be low and remain wet throughout much of the growing season, while another area may be sandy, rocky, shallow, or dry. Look at the plants that are growing there now, or in similar conditions off-site; they will give you good clues about the soil condi- tions. If you are planning to purchase material for your buffer, keep these varying conditions in mind. Soils with little organic matter -- often found in densely developed areas -- can be im- proved with the addition of compost and lime. See the folder pamphlet, Know Your Soil, for further discussion of how to assess your soil for plant needs.
your lot steep or flat? Steeper areas are more sensi- tive to erosion and require a variety of root types for permanent stabilization. (Remember, water runs downhill faster in steeper areas and carries larger soil particles farther and faster.) If your house or camp is located on a hillside, try to develop as deep a buffer as possible in order to absorb runoff from roofs, drive- ways, and outbuildings.
method is to cover the pathway with a 2-inch layer of bark mulch or wood chips. This will have to be renewed periodically, as the material decomposes -- about once every couple of years. Other options include seeding the pathway with an appropriate grass mix; setting paving stones, bricks, cement tiles, or slate in a ma- trix of mulch, wood chips, or crushed stone; or by creating a boardwalk. Remember that winding pathways are preferred so that mov- ing water will not create channels.
To ensure culvert stability and to prevent erosion, the use of stone for headwall protection is strongly recom- mended. Larger flat rocks are placed on top and to the side of the pipe, and smaller rocks are used to fill in open spaces. Where there is a drop of 6" or more between the base of the culvert and the bottom of the ditch, additional stone should be added to create a small apron. These practices will greatly lengthen the life of a culvert, and will decrease the frequency of maintenance. Detailed plans for culvert protection are included in the Camp Road Manual.
can be installed on roads to divert water and sediments into stable, vegetated areas. This will not only control erosion, but save on maintenance costs of your gravel driveway or camp road. These diversions include open-box culverts, "rubber razor" water bars, or broad-based drain- age dips. Detailed plans for installing open-box culverts and the broad-based drainage dips are included in the Camp Road Manual published by the Kennebec County Soil & Water Conservation District. Plans for the "rubber razor" are available from An- droscoggin Valley SWCD. All are inex- pensive to install -- much less expensive than frequent resurfacing.
Our lakes and ponds are for all to enjoy!Our lakes and ponds are for all to enjoy!^ Our lakes and ponds are for all to enjoy!Our lakes and ponds are for all to enjoy!
culvert (^) headers
gravel
rock
water bar
water
You have several options when designing a buffer.
Look carefully at:
road or public way, pathway to the lake, boathouse, etc.
and financial constraints.
Consider:
access to the water? deter wandering pets?
eas?
lots? from recreationists on the water?
lot?
ing?
tered from wind or the hot sun?
Designing the Buffer
T H E B U F F E R H A N D B O O K
This design includes as- pects of a good buffer. Note: ♦ the curved driveway ♦ the small, defined yard ♦ the buffer between the road and the house ♦ the buffer between the house and lake in- cludes low shrubs to maintain the lakeside view and a winding path.
able things and let the rest of the area revert around them. For instance, if you have a number of trees on your lot, in relatively close proximity to the shoreline, you can fill in the spaces be- tween them with shrubs, herbaceous plants, and groundcovers. Following this option generally means it will take fewer years to get the buffer fully established, and will require only a moder- ate commitment of time and money on your part. Advantages of this option are that you will have more choices in the plants that you want to have as a part of your landscape, and you will have a head start on getting the buffer in place.
This property owner added beds of perennials and shrubs to the tree line above a steep banking. The steep banking was allowed to revert to native species. Use of shorter plants between the trees allows residents to still observe activities on the lake.
Using Native Plants in Vegetated Buffers*
Native plants are defined as those that were observed in the natural landscape at the time of contact between Europeans and indigenous peoples (about 1450 A.D.). Use of native plants in landscaping, particularly in vegetated buffers, are of value for the following reasons:
♦ The plants are appropriate for our regional climate. They have adapted to this area over time; therefore, there is less maintenance required for these plants. ♦ Native plants have significant wildlife value, as they are used by many birds and animals for food sources, and for breeding habitat.
♦ One-third of the plants native to New England are endangered; there are many inva- sive exotics that displace natives.
♦ Use of native plant materials allows us to celebrate our regional differences. ♦ There are many beautiful native plants. Many local nurseries carry such material, and can provide specific recommendations for appropriate siting.
-From a presentation given by Jeff Horton, Shaker Hill Nursery, Poland, ME
*The native or naturally-occurring plants described in this booklet are marked with an N.
establish a protective strip, but will require a more concentrated effort and generally more money. You can spread out your planting over several seasons or several years; an example might be to plant trees the first year, followed by shrubs, and groundcover the second year. This way, you will have absolute control over the design.
Or, combine the options to accommodate your needs as well as those of the buffer strip. For example, abandon mowing along the immediate shoreline, and install a landscaped design to the landward side of that strip for you and your family to enjoy. Which ever option you choose, try to visualize what you want the buffer to look like in five, ten, or more years.
♦ Choose plant material appropriate for your plan. Don't, for instance, plant trees that grow tall naturally and then try to prune them heavily, instead, opt for a tall shrub.
♦ Make use of hardy species that require little maintenance, and no fertilizers.
♦ If you are purchasing plants, deal with a reputable, local firm that can help you select the healthiest plant material available, and who can answer questions on planting considera- tions.
The most important decision to make about your buffer is when to get started. A good design and action plan are vital for sustainability, but do not delay your project. Vegetated buffer strips are a proven means of controlling erosion and other sources of nonpoint source pollution. Help to protect the water quality of your favorite lake or stream by starting your vegetated buffer project as soon as possible.
The installation of this landscaped buffer is in progress. Note how the design enhances, not blocks, lake views.
ing it with plants and additional soil. Once all plants are in place, the whole bed should be mulched with at least four inches of well-rotted bark mulch or compost. The mulch will absorb moisture, discourage weeds, and eventually decompose into the foundation of that well- regarded duff layer. Remember to keep new plants watered throughout their first and second seasons. Once the root systems are well-established, the plants can survive with little attention, except in times of extreme drought. Give them a little "TLC" to get them started. If the soil in your area is lacking in organic matter, is clayey, or is heavily-compacted, you will want to add compost to your plantings for the first few years in order to build a healthy soil. Keep in mind that a healthy soil supports small organisms that help to break down nutri- ents and pollutants for uptake by plants.
Mulching your buffer plants In undisturbed wooded areas, a natural duff layer builds up over time. Duff is an impor- tant part of the ecosystem for a number of reasons. Plant waste (fallen leaves, pine spills, and branches) decompose over time and provide a natural fertilizer for living plants -- this is na- ture's way of recycling nutrients. Duff also holds quantities of water in reserve, by soaking up runoff and allowing the moisture to be slowly absorbed by plants and underlying soils. Mulch, such as composted wood fiber or composted yard wastes, mimics natural sys- tems. Newly-planted shrubs and perennials (or herbaceous plants) will benefit from this added layer of protection. Mulch protects areas of bare soil and will also deter unwanted "weeds" in the more formally-designed buffer systems. Be sure to use mulch that has been composted for six months to a year so that nutrients are not leached from the soil. Use about four inches of the material around plants and on any area of bare soil. Remember though, to give plants about an inch of "breathing room" around their bases so that the plants aren't smothered. Af- ter planting, allow leaves and evergreen needles to accumulate.
Composting yard and kitchen wastes Composting is a good way to recycle nature's resources, and for most property owners, there is already an abundant supply of raw materials at hand. Leaves, grass clippings, and other yard waste, as well as non-meat kitchen scraps, can be combined and allowed to decompose for a year. The compost provides a fine mulch or soil amendment for use in your buffer or other garden sites. Well-rotted compost is a soil amendment which has been approved for use in the shoreland zone by the Maine Department of Environmental Pro- tection. A brochure developed by the University of Maine Coopera- tive Extension Service (in the folder) will help you establish a system for composting yard wastes. See the reference section for further sources of information.
Use of fertilizer and pesticides One of the most important roles of buffers is the uptake of excess nutrients; in lake wa- tersheds, phosphorus is the nutrient of greatest concern. When planting your buffer, choose materials that will not require constant feeding and spraying and that are naturally hardy and resistant to insects and disease. Keep air circulation open to avoid fungal diseases. If plants still appear sick, remove and destroy them to prevent spread of the disease among similar plants. If you really feel that you must use a fertilizer, use it sparingly! Apply a liquid that will immediately soak in and will not sit on the surface to be washed into the water by heavy rains. Be stingy -- apply fertilizer only during the growing season so that it is taken up immediately. If
you must spray for pests or disease, start treatments with the most benign method of control possible, such as baking soda combined with water and a small amount of horticultural oil or a non-phosphate dish soap and water. Use pesticides as a last resort; they are harmful to aquatic life and beneficial insects. Selecting plants that will attract a variety of birds provides the added benefit of an effective means of bug control. Information on safe means of pest and disease control is available from your Cooperative Extensive Service, from organic gardening references, and from many reputable nurseries.
Improving soil health Where soils have been highly disturbed as a result of construction, or have become heavily compacted as a result of years of foot traffic, it is recommended that well-rotted com- post be added when plants are introduced. Mulch plants well and water thoroughly until the plants are established. Most shrubs, once established, are actually best left to fend for them- selves. Remember too, phosphorus and nitrogen will be supplied by runoff, and will be recy- cled from fallen plant wastes.
Where you have a lawn, such as in the area next to your home or camp, spread lime to sweeten (increase pH) the soil. Adding lime changes the pH of the soil which in turn will help deter the spread of many weeds. Hand digging weeds is another “environmentally friendly” way of controlling un- wanted species. Set your lawn mower high enough so that grass length is two to three inches or more. Should you need to rake the lawn, save those clip- pings for your compost pile!
Work to improve soil health. Compost and mulch will help to provide a beneficial envi- ronment for soil organisms and will also help to make the soil more absorbent because of the
help you to assess your site's conditions.
