Why Stormwater Matters
Impacts of Runoff on Henry County Watersheds
Land development has a profound influence
on the quality of Henry County waters. To start, development
dramatically alters the local hydrologic cycle which is the
process by which the majority of rainwater, falling on undeveloped
land, infiltrates into the soil and slowly makes its way to
creeks and lakes. The hydrology of an undeveloped site changes
during the initial clearing and grading that occur during
construction. Trees, meadow grasses, and agricultural crops
that once intercepted and absorbed rainfall are removed and
natural depressions that temporarily pond water are graded
to a uniform slope. Cleared and graded sites erode, are often
severely compacted, and can no longer prevent rainfall from
being rapidly converted into stormwater runoff.
Click the image
above to view a larger image.
The situation can worsen after construction.
Roof-tops, roads, parking lots, driveways and other impervious
surfaces no longer allow rainfall to soak into the ground.
Consequently, most rainfall is converted directly to runoff
while ground water flows slow to a trickle. The increase in
stormwater runoff can be too much for remaining natural drainage
systems to handle. As a result, the natural drainage system
is often altered to rapidly collect runoff and quickly convey
it away (using curb and gutter, enclosed storm sewers, and
lined channels). The stormwater runoff is subsequently discharged
to streams, reservoirs or lakes. The following example demonstrates
the effect of stormwater runoff.
Click the image above
to view a larger image.
The overriding condition that governs
the quantity of stormwater runoff is the amount of impervious
surfaces located on your property (driveways, roofs, carports,
Stormwater quality, however, is governed by the accumulation
of pollutants on the entire surface area, regardless of whether
it is grassed or paved. As the use of chemicals around the
home such as fertilizers, pesticides, herbicides, engine oils,
anti-freeze and similar products increases, the more degraded
the stormwater runoff from your property will be.
Although the effect of one property
on the quality and quantity of stormwater runoff may seem
insignificant, the cumulative impact from hundreds of thousands
of properties across the State is destructive to our water
quality. The following activities will minimize stormwater
runoff from your property:
- Limit the amount of impervious
surfaces in your landscape. Use permeable paving surfaces
such as wood decks, bricks, and concrete lattice to allow
water to soak into the ground. Where possible, direct runoff
from impervious surfaces across vegetated areas.
- Allow "thick" vegetation or "buffer
strips" to grow alongside waterways to filter and slow runoff
and soak up pollutants.
- Plant trees, shrubs, and groundcover.
They will absorb up to fourteen times more rainwater than
a grass lawn and they don't require fertilizer.
For more information on environmentally
friendly planting and landscaping designs, contact Henry County
Stormwater Management Department or the Henry
County Extension Office.
Additional activities that will reduce
fertilizer, pesticide, and sediment runoff:
- Use natural alternatives to chemical fertilizers and pesticides.
- If you must use fertilizers or pesticides, test your soil
to determine the appropriate amount.
- If a lawn care company services your lawn, make certain
it is not applying "blanket" applications of fertilizer
- Ask if they have conducted soil tests and a pest analysis
to determine appropriate applications.
- Also, re-sod or reseed bare patches in your lawn as soon
as possible to avoid erosion.