“Introduction
to Riparian Buffers.”
Robert Boucher, Committee on the Environment
The River
Hills Committee on the Environment is working to restore and protect the
riparian buffers which in turn restore and protect the quality of all our
Village waterways. Because riparian buffers are the single most effective
protection for our water resources, it is vital that all residents support the
preservation of riparian areas along the
River buffers
to be most effective should include native vegetation and be as wide as
possible. Riparian strips of native vegetation, shrubs, and trees 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
communities they shelter. Natural riparian buffers have been lost in many
places over the years. Restoring them will be an important step toward
improving water quality, riverbank stability, wildlife, and the aesthetics of
our waterways in River Hills.
HOW BUFFERS GO TO WORK
1. Water Quality
Sediment
Filter
Riparian
buffers help catch and filter out sediment and debris from surface runoff.
Pollution
Filter, Transformer, and Sink
The riparian
buffer traps pollutants that could otherwise wash into surface and groundwater.
Stream Flow
Regulator
By slowing the
velocity of runoff, the riparian buffer allows water to infiltrate the soil and
recharge the groundwater supply. This helps control flooding and maintain
stream flow during the driest time of the year.
2. Bank stability
Bank
Stabilizer
Riparian
buffer vegetation helps to stabilize streambanks and reduce erosion. Roots hold
bank soil together, and stems protect banks by deflecting the cutting action of
waves, ice, and storm runoff.
Bed Stabilizer
Riparian
buffers can also reduce the amount of streambed scour by absorbing surface
water runoff and slowing water velocity.
Stronger flow can scour streambeds, and can disturb aquatic life.
3. Fish and wildlife
Wildlife
Habitat
The
distinctive habitat offered by riparian buffers is home to a multitude of plant
and animal species, including those rarely found outside this narrow band of
land influenced by the river. Continuous stretches of riparian buffer also
serve as wildlife nesting and travel corridors.
Aquatic
Habitat
Forested
riparian buffers benefit aquatic habitat by improving the quality of nearby
waters through shading, filtering, and moderating stream flow. Shade in summer
maintains cooler, more even temperatures, especially on small streams. Cooler
water holds more oxygen and reduces stress on fish and other aquatic creatures.
Recreation and
Aesthetics
Forested
buffers are especially valuable in providing a green screen along waterways,
blocking views of nearby development, and allowing privacy for riverfront
landowners.
BUFFER WIDTH
Science has
discovered the basic bare-bones buffer is 50' from the top of the bank. You get
more protection with every foot. The Wisconsin DNR recommendation is 75 feet.
To Stabilize Eroding Banks, 35 to 50 feet
To Filter Sediment and Attached Contaminants from Runoff, 35
or more
To Filter Dissolved Nutrients and Pesticides from Runoff,
100 feet.
To Protect Fisheries, 100 feet, the wider the buffer the
healthier the aquatic food web.
To Protect Wildlife Habitat, 300 feet is a generally accepted minimum.
DECIDING ON THE RIGHT WIDTH FOR YOUR PROPERTY
From
the top of the stream bank, turn back and take 15 long paces. This should carry
you 50' from the bank. This area should be covered with native vegetation.
Another 15 paces brings you about 100' from the bank. The ability of a buffer
to remove pollutants is uncertain if it is narrower than this. A 100' buffer
will generally remove 60% or more of pollutants, depending on local conditions.
It will also provide food, cover and breeding habitat for many kinds of
wildlife but only fulfill a few needs for others, such as travel cover.
Current Status
of River Hills Buffer Ordinance:
River
Hills has an ordinance which has been in place since 1973 to protect the
The
following in the code is most pertinent.
“Section (3)
Intent… (D) Preserve and protect
remaining, wetland, woodland and other significant natural resources which
contain the best remaining wildlife habitat and scenic areas within the
village;… (F) Provide for the administration and enforcement of this Ordinance
and penalties for its violation.”
Prohibited
in the “Primary Environmental Conservancy
District” are “[all uses of (a) land
(b) water (c) air]… which would
substantially impair the natural fauna, flora, watercourses, water regimen or
topography.”
Currently
two members of the committee on the environment and two of the village trustees
are working on an ad hoc committee to update the ordinance.
Robert
Boucher, Committee on the Environment