| By Loretta Clawson and Wendy Patoprsty
The following column is part of a series by the Boone Area
Chamber of Commerce everGREEN Committee, which, according to
organizers is tasked with the mission: To promote the
adoption and practice of sustainable development principles
which foster economic prosperity while preserving the environment
for future generations.
Many communities in North Carolina have seen their forest replaced
with impervious development. The roof tops, parking lots, and
roads dont allow water to slowly infiltrate into the ground
to replenish our groundwater. Instead that stormwater washes
into the gutters and quickly into our streams causing a flashy
rise in the water levels of the rivers.
The excess stormwater that ends up the stream can lead to pressure
on the banks causing erosion, which can be very harmful to water
quality. Stormwater is considered non point source pollution,
which is the leading remaining cause of water quality problems
in the nation according to State reports.
Non-point source pollution comes from many diffuse sources including;
excess fertilizers from agricultural and residential lands,
oil, grease and toxic chemicals from urban runoff, sediment,
salt, bacteria and nutrients from faulty septics and livestock
and pet wastes. Non point source pollution is the main reason
why 40% of our nations surveyed rivers, lakes and estuaries
are not clean enough to meet basic uses such as swimming or
fishing.
The environmental community has been recently encouraging homeowners
and developers to install simple rain gardens to filter runoff
and recharge aquifers. While most rain gardens are small, collectively
they can have enormous environmental benefit.
Rain gardens are shallow depressions designed to collect rain
from impervious surfaces and lets plants, bacteria, and soils
cleanse the water as it seeps slowly back into the ground. They
are beneficial because they reduce the amount of stormwater
that enters a local stream, river, or lake. These areas can
be a beautiful plant garden that can blend right in to the landscape.
The plants, shrubs and trees that are planted in this area should
be water tolerant not water loving. This area is not intended
to be a wetland.
The rain garden should be designed so that water regularly inundates
the soil for short periods of time after a storm event.
Rain Gardens remove pollutants using physical, chemical and
biological mechanisms. They use absorption, microbial action,
plant uptake, sedimentation and filtration.
Plus the rain garden helps to replenish groundwater by allowing
infiltration of Stormwater runoff. The exact ability of rain
gardens to remove pollutants has not yet fully been quantified.
However they do appear to be effective in removing the most
critical pollutants found in Stormwater runoff including most
metals, total phosphorus, and total nitrogen.
The Internet has numerous sites that will assist individuals
with the location, construction, and maintenance of a rain garden.
Additionally, North Carolina Cooperative Extension Service has
illustrated materials explaining how to construct and maintain
rain gardens.
Locally, a number of rain gardens have been installed on private
and public properties, all of which are contributing to improving
the water quality of our rivers and tributaries.
On a larger scale many communities have constructed a number
of wetlands, which have similar function and impact on water
quality as rain gardens, but on a much larger scale, treating
multi-acre drainage areas.
When next considering a new landscaping project, we hope that
you will consider constructing a rain garden that will not only
beautify your yard, but protect the environment!
Loretta Clawson is the mayor of Boone. Wendy Patoprsty is an
agent with the N.C. Extension Service.
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