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In a forested landscape (pre development), most of the falling rain is
absorbed by the forest plants and soils.
Nearly half the rain is caught in the leaves and/or taken up by the roots and
evaporated back into the air.
Much of the rainwater soaks into the spongy soil and travels through the soil,
emerging as springs and seeps that feed streams with slow, clean H2O.
Some of the rainwater seeps into deeper aquifers,
aquifers recharging the water
table; Only a small amount becomes “surface runoff”.
In a developed landscape, with fewer trees and more paved areas, less
rainwater is absorbed, less is infiltrated, or evaporated, and much more rain
water becomes runoff, or “stormwater”.
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Here is one more visual representation of stormwater runoff from developed sites.
Sources of pollution: Dog waste, lawn chemicals and oil and dirt from our cars
There is a common misconception that some of Lacey’s stormwater goes to the
LOTT Alliance for treatment, when in fact, NONE of Lacey’s stormwater goes to a
wastewater treatment plants.
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Some of the sources of pollution:
1) Soap from car washing on impervious surfaces like driveways—the
alternative is to wash cars on the grass or take them to a commercial car
wash
2) Fertilizers and pesticides improperly or excessively applied or dumped
illegally. Using slow release or organic fertilizers eliminates unnecessary
chemicals entering our waterways.
3) Oil and automotive fluids…either leaked or dumped illegally. For cars that
are leaking oil, you can use a piece of cardboard underneath your car in the
short term.
4) Animal waste from dog droppings. Also human waste from improperly
functioning on-site septic systems. We ask that whether at home or on a
walk that dog
gp
poop
p is always
y scooped,
p
bagged,
gg
and p
placed in the trash.
5) Dirt from construction sites. Local governments require erosion control
plans for construction sites, large or small, so if you see dirt running into the
street near a construction site, we recommend you call the local government,
the City or the County.
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Stormwater facilities are the backbone to successful stormwater management.
There are many different kinds of stormwater “facilities”…..we’ll zero in on those
most common to neighborhoods.
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The first thing that stormwater facilities do is:
Collect stormwater
A catch basin is the most typical type of storm
facility designed to “collect” the stormwater.
In this catch basin drawing, you can see where
water falls through the grate and down into
the sump area. Once the water fills to a
certain point, it flows through the outlet pipes
and off to the next step in the process, which
varies greatly depending on the site.
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The second thing that stormwater facilities do is convey stormwater.
Here are3 examples of storm facilities that were designed to divert stormwater out
of our streets and yards.
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Here are 4 different examples of stormwater facilities designed to “treat” the
polluted runoff.
A wet pond is usually constructed with a liner that holds onto the polluted
runoff and allows the sediments to settle out before overflowing into another
facility that infiltrates the water back into the ground, or disposes of it into
surface waters. A wet pond should not be covered by vegetation (or very
little vegetation) as this will not allow the pond to hold as much water as it
was designed to hold.
A constructed wetland is designed to allow plants to soak up the polluted
stormwater naturally. These facilities are not lined and should be covered by
g
vegetation.
A bio-swale is a ditch that utilizes grass or other plants to treat the polluted
stormwater, and it flows through the depression
Bioretention is a new technology that we will be seeing more and more of in
th ffuture.
the
t
Th
The ttype shown
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h
here iis also
l known
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as a rain
i garden.
d
Th
These
facilities are designed to treat and store runoff on site instead of conveying it
to a large combined pond or facility somewhere else. It is a method that
does a great job at mimicking mother nature by treating and storing runoff
where it originates.
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Infiltration ponds or “dry ponds”, allow the stormwater a place to hang out during the
storm and to slowly soak back into the ground. The soil beneath these facilities are
also able to remove some of the pollutants from the stormwater before it finds its
way back to our groundwater or streams.
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If you are unsure which facilities in your neighborhood you are responsible for, the
City is available to assist in making that determination.
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We have a handout as a resource as you start your inspections
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Get everyone involved in facility inspections and work parties – after all,
you’re all co-owners of your facilities.
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Some dry ponds are not seeded with grass and therefore not mowed
regularly, but still need to have vegetation removed from the bottom. (weed
whacker or brush hog or weed wrenches)
We don’t require that the sides be weed-free, but it will make maintenance
easier.
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Since it is your pond to maintain, it is a good idea to install signs like this one to
inform the residents that this area is a stormwater facility. We provide these to
Lacey home owner assocations for free.
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