Page 25 - Southern Exposure - September '19
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Southern Exposure, Page 25
NorTherN NoTeS
Streets, Swales And Stormwater Management
By O’Neal Bardin Jr., Executive Director, Northern Palm Beach County Improvement District
Streets streets are used to convey stormwater, in order to identify and transport the stormwater to
Streets are an important part of Northern Palm Beach when problems may occur. lakes, canals and other outlets.
County Improvement District’s overall Stormwater Streets And Stormwater Management Did you know that in
Management System. Both the storm sewers located below Many streets are designed and built with curb and gutter very heavy rains, some water
the street, ditches or swales located along the street, and along the street and with storm sewers underneath the standing in streets or swales is
the roadway itself serve to convey stormwater to designed pavement. The curbs and gutters direct stormwater from the part of the flood control design
locations. At times blockages can occur, which can cause pavement into the storm sewers. These storm sewers not only plan and is expected? Your
undesired flooding conditions that may cause roads to become collect water from the roadway, but also connect to other neighborhood lake’s water level
impassable. It is important to understand the basics of how drainage systems to collect water from yards and subdivisions may seem to rise alarmingly, but
that’s not likely to last. If the
system in your neighborhood
is working properly, levels will
return to normal soon after the rain has stopped. A heavier,
more widespread and longer-lasting storm will require more
time for local, secondary and regional systems to absorb
the excess water. Because these flood control systems are
connected, what’s happening upstream or downstream from
your neighborhood also has an impact.
Keep It Clear
Many stormwater blockages in streets occur due to clogged
storm sewer inlets. If there is an inlet in the street adjacent
to your home, residents are asked to keep this drain clear of
all obstructions including leaves, grass and debris. Debris at
storm sewer inlets also build up after a storm event, which is
a good time to check the inlet to make sure that the system
will work well in the next storm.
Too Deep To Drive?
If during or after a rain event you arrive upon a roadway
where you cannot determine the depth of the water in the street
– for your own safety – do not drive down the street. Find an
alternate route.
Swales
Chances are if you’ve lived in South Florida long enough,
you’ve heard at least one person refer to a “swale.” A swale
is a graded and engineered grassy area of land appearing as
a linear, shallow, open channel, that stretches from the edge
of the sidewalk in front of homes (or the property line if there
is no sidewalk) to the edge of the street. Swales are typically
vegetated with flood tolerant, erosion resistant plants. Swales
are one of the most commonly used stormwater practices. For
many years, swales have been used to direct runoff from rural
highways and residential streets. Today, swales not only direct
stormwater but also help filter runoff and reduce pollutants.
A swale slows down the rapid flow of stormwater runoff
by ponding water between its sloping sides, often called
berms. The ponding not only slows the rate of flow but allows
pollutants to settle out of the water. Ponding facilitates water
quality improvements through infiltration, filtration and
sedimentary deposition. Collected stormwater is expected
to drain away through the soil within several hours or days.
When the swale becomes full, the cleaner surface water will
spill over the berm and slowly run into a local water body.
Eventually, the remaining ponded water will either evaporate
or infiltrate into the soil.
Maintain Proper Swales
• Let water pond. Runoff should temporarily pond in the
swale for 24 to 36 hours, sometimes even up to 72 hours.
• Mow the swale but keep it at a good grass growth. Tall
grass slows water movement.
• Remove and compost leaves and grass clippings from
Friday, October 18th swales.
• Minimize use of fertilizers, pesticides and herbicides
within 50 feet of a swale.
5-8 PM KIDS AREA & BOUNCE HOUSES • Do not pile garbage, trash, leaves, limbs or garden
debris in swales— this adds pollutants which can wash into
SWAT & K9 DEMONSTATIONS downstream waters.
• Do not pave the swale — this reduces the filtration and
infiltration of runoff.
FUN FOR THE ENTIRE FAMILY • Do not park vehicles in the swale— this compacts the soil
so less runoff soaks in. It also destroys the vegetation in the
swale that is needed to filter the pollutants out of the water.
COMMUNITY INITIATIVE • Do not alter the design of the swale. Any changes will
require a permit as they may affect drainage.
Please keep in mind that there is a direct link between what
we do around our home and the water quality of our canals,
ponds, lakes and wetlands.
NPDES tip: It is important to never dump any debris,
including but not limited to landscape waste, garbage or
chemicals into a storm sewer inlet. While bulky materials can
cause flooding, chemicals and other wastes that are dumped
into a storm sewer eventually drain into lakes and canals,
which threaten fish and wildlife and pollute the water. Please
check our website for information regarding illegal dumping.
