LOW IMPACT DEVELOPMENT
The healthy, beautiful, and cost effect choice for your community!
What is Low Impact Development?
Low Impact Development is an environmental and economical response to the limitations of traditional stormwater management. LID practices consist of four basic elements: 1) conserving as much natural area as possible, 2) minimizing hard
surface areas such as streets and parking lots to improve water infiltration, 3) retaining storm water on site as much as
possible to reduce runoff and flooding, and 4) encouraging rainfall to soak into the ground through permeable topsoil. LID
can be implemented in new housing/commercial developments and existing housing/commercial areas. While it is easier
to use LID at the start of development, most LID practices can easily be retrofitted to accommodate existing structures.
LID pays special attention to a construction site’s hydrology. Engineers carefully consider on-site storm water management and the retention of top soil, aiming to design construction projects with the lowest possible impact on the local environmental systems. LID helps reduce runoff of oil, hydrocarbons, and heavy metals from parking lots and streets; it also
reduces the runoff of herbicides and excess fertilizer from lawns, as well as diminishing topsoil erosion. In addition
to catching chemical runoff, LID also helps minimize flood damage through the use of more permeable surfaces which
allow for greater infiltration of water into the soil.
Benefits of LID
Communities who have adopted LID practices have experienced:
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Improved water quality: less toxic runoff leads to healthier
rivers, streams, ponds, and lakes.
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Less costly flood events: because stormwater soaks into the
ground, it does not rush toward and run into basements.
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Enhanced community aesthetics: LID community development means less pumps, pipes, outfalls, and fenced basins
and more trees, flowers, and green space.
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More recreation opportunities: with more green space, communities can develop more parks, ponds, and trails.
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Restored aquatic habitat: less runoff means that less sediment is carried into streams, wetlands, and lakes.
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Improved groundwater recharge: rainwater can flow
through the soil into the aquifers instead of running off as
discharge.
Types of Low Impact Development
Large hard surface areas, such as
parking lots or patios, can lead to
a higher risk of toxic runoff and
flooding. Breaking up these areas
with rock gardens or stretches of
vegetation, known as bioswales or
bioretention, can help slow water
movement and reduce runoff and
flooding.
Rain gardens & bioswales are an
attractive way to capture excess
stormwater on your property.
Rain gardens make it easier for
water to be absorbed by
aquifers—instead of by your
basement. The movement of the
water through the rain garden
also works as natural filter!
Bioswales & Bioretention
Rain Gardens
Planting native grasses allows
landscapers to take advantage of
the existing soil and climatic
conditions. Plants grow with less
fertilizer, chemicals, and
watering, all of which improve
local water quality.
Native Landscaping
Another way to reduce excess
runoff from hard surfaces is to
use permeable pavers and
pavement. These materials allow
water to soak through the
surface, rather than run off it.
This reduces flooding and allows
the soil to naturally filter water
before it reaches rivers and
lakes.
Permeable Surfaces
Revitalizing your soil can open up
a world of opportunities for your
home or business. Healthy soils
makes it easier for grasses,
flowers, and tress to grow with
less chemical application—all
while helping local water quality!
Soil Restoration
Properly managing your front
yard can have a huge impact on
water quality! By knowing how to
maximize the amount of lawn you
have, what variety of grass to
plant, and how often you should
be mowing, you can help reduce
levels of chemical contaminants
in local rivers and lakes.
Turf Management
Using LID Works!
Low Impact Development is more than a theory. Case studies across the US have proven that LID reduces flooding and
water pollution. According to the EPA, Seattle Public Utilities installed 12 bioretention cells, and during 235 precipitation
events, stormwater was completely absorbed in 186 of the events. That’s a 79 percent success rate! No runoff or pollution
was generated during these events. In Philadelphia, two years after replacing impervious surfaces with permeable material, the city save an estimated $340 million by not having to store excess sewer overflow. Philadelphia Water Development estimates that the shift has prevented approximately 13 tons of sediment from reaching the local creek each year!
The Costs of LID
One of the struggles developers face with LID is the concern of increased costs. During initial stages of development, permeable pavers,
bioswales, and other LID strategies may seem like an unnecessarily
high cost to incur. However, case studies have shown that, over the
long run, LID saves communities money. For instance:
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Bioswales, narrower roads, and smaller parking lots can save money by reducing the amount of pavement, curbs, and gutters needed.

In reducing the amount of impervious surfaces (streets, driveways,
parking lots) and using bioretention areas to capture runoff, communities save money by eliminating the need for costly detention
basins, pipes, and pumps.

LID reduces flooding, which means communities have reduced
flooding damages and associated costs.

Designing more compact residential lots saves money by reducing
site grading and building preparation costs. Furthermore, developers can increase the number of lots for sale.
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The preservation of a site’s natural features, such as trees, wetlands, and native grasslands, can increase the value and sale price
of lots.