From Runoff to Renewal: How Low-Impact
Development Can Reduce Stormwater Runoff
and Protect Water Quality
What is stormwater?
The water that flows down rooftops,
sidewalks, parking lots and streets after
rains and during spring runoff.
Where is stormwater a problem?
When rain and snow fall to the ground in
undeveloped, vegetated areas, the water
percolates through the soil and is taken up
by plants. What isn’t used by the plants
saturates the soil; this is the natural system
that eventually helps recharge our
groundwater supplies. However, in areas
where we have covered the ground with
buildings and parking lots and removed
plants, stormwater cannot enter the soil
and therefore has to “runoff” into a storm
drain or nearby water body.
Rain is natural, why does
stormwater cause concern?
As it flows across human-made surfaces,
water gathers everything from sediment
to pesticides and toxic chemicals and
mainlines them into our waterways. In
some areas, this runoff also overwhelms
outdated sewage infrastructure, spilling
raw or partially-treated sewage into
waterways and the Great Lakes.
What can we do to protect
our lakes, rivers, wetlands and
groundwater from stormwater
contamination, combined sewer
overflows and erosion?
Fortunately, there are easy and affordable
solutions communities and individuals can
use to reduce runoff from development.
Low-impact development (LID), one set of
techniques, is at heart a strategy to make
the built environment function like the
natural environment. It involves low-cost
practices as well as site planning and
design to take into account on-site,
natural features, to maintain an area’s predevelopment
hydrology.
Some examples of LID practices include:
- Vegetated roofs,
- Permeable paving,
- Rain gardens,
- Rain barrels, and
- Soil amendments.
LID also involves site planning and design,
such as:
- Preserving natural vegetation,
- Clustering development & preserving open space, and
- Designing buildings and roads to minimize impervious surface cover.
How is Low-Impact
Development different from
traditional development?
While traditional development treats
stormwater as a waste product, creating
more runoff by removing native vegetation,
and covering the natural landscape
with concrete, asphalt and buildings that
make the ground less able to absorb
water and filter pollution, LID utilizes this
water as a resource.
What tools can local
communities utilize to turn their
stormwater into a resource?
Master plans, zoning ordinances or
bylaws, and stormwater ordinances can
explicitly endorse and encourage
practices such as LID techniques that
residents and local leaders find desirable,
while revising older parts of ordinances
that inhibit effective stormwater
management.
The key features of any LID stormwater
ordinance should include:
- A standard of no net runoff from new development,
- Flexibility for developers to use a wide range of non-structural LID practices to achieve the standard, and
- Revision of outdated requirements that interfere with LID, such as requirements for excessively wide streets, large setbacks or traditional stormwater infrastructure.
Are stormwater issues
isolated
to particular areas?
Polluted stormwater is a
significant and growing
problem throughout the Great
Lakes Basin. However, numerous
opportunities exist within
the developed landscape to
control stormwater flows close
to the source. Reducing
stormwater runoff is simpler
and cheaper than building
expensive stormwater infrastructure,
and more effective at protecting our waterways
and the Great Lakes.
Where can resources and
information be found?
One resource for groups and individuals looking to
promote LID in their community is the Public Interest
Research Group in Michigan’s (PIRGIM) website,
www.pirgim.org, where you can find the report,Waterways
at Risk, as well as an LID fact sheet, model ordinance and
media toolkit. GLAHNF will also be developing additional
stormwater tools this summer.
For more stormwater related resources,
see pages 12 and 13 of this newsletter.
For more information:
Abby Rubley, Great Lakes Advocate
Environment Michigan
103 E. Liberty St., Ste. 202, Ann Arbor, MI 48104
Ph: (734) 662-9124 • E-mail: arubley@pirgim.org
Disclaimer:
The interpretations and conclusions presented in this newsletter represent the opinions of the individual authors. They in no way represent the views of the Tip of the Mitt Watershed Council, the C.S. Mott Foundation, subscribers, donors, or any organization mentioned in this publication.
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