This photo essay was designed to show some methods used to control erosion
before, during and after construction and to review some long term storm water
management methods installed prior to your business operations. Once you
have completed reviewing this page, hit your browser's "back"
button to return to the storm water small business pages.
Before reading the following photo essay, note that The Wisconsin Department
of Natural Resources and University of Wisconsin Extension have each published
a technical guidance document to assist you in creating your plan.
When beginning to locate your small business on a new property, it
is important to design your site with erosion control and construction
storm water management practices in mind. Minimizing land
disturbance and keeping native vegetation and soils in place will have
the greatest long term impact on protecting the watershed and any nearby
water bodies (lakes, rivers and wetland areas) where runoff ultimately
travels to. This up-front planning will save dollars otherwise earmarked
for storm sewer fees, lawn creation and maintenance costs, and disposal
charges, to name a few.
An excellent resource published by UW Extension is Preserving
Trees During Construction - pdf (222 K)(EXIT DNR).
But some land disturbance will ultimately occur due to
building footprint needs, parking areas, driveways, etc. Since a construction
and long term storm water management plan is required prior to any construction
activities, please read through the following key points to assist you
in creating and implementing sound erosion control and flow management
plans for your small business site.
Site Phasing
When first creating your erosion control plan, try to
design site phasing into the construction. Site phasing
minimizes soil erosion by having smaller portions of your site disturbed
at any one time (e.g. fitting the development to the topographic "lay
of the land", minimizing the development footprint by clearing
only the land required for buildings, roads, and utilities, and providing
buffers from natural drainage systems and water bodies).
For more information on site phasing, please refer to
the following article: "Practical
Tips for Construction Site Phasing"- pdf (680 K) Published
by the Center for Watershed Protection (EXIT DNR)
Sediment Controls
Sediment
control practices are designed to remove some of the soil particles
that are suspended in runoff. By using properly installed silt fencing,
straw bales, sediment traps or sediment basins, any sediment or other
materials will be held in place on the construction site and not end
up in wetlands, lakes, or rivers. These should be written into the erosion
control plan and installed within 24 hours of any land disturbance.
Silt fencing, if installed improperly, can cause a greater
release during a major rainfall event.
Photos used with permission from the Center
for Watershed Protection.
A good source of information on proper instrallation of
straw bales and silt fences is the UW Extension publication "Erosion
Control for Home Builders" - pdf (EXIT DNR). This document
covers the more common erosion control practices used during development
of a site.
Erosion Controls
Mulches, blankets and matting, seeding and soil stabilizers
are used to stabilize a recently disturbed area and minimize the dislodging
of soil particles by raindrop impacts and flowing water. Some
advantages include: reducing flow velocities of storm water through
the area and reducing moisture loss when seeding and planting is done.
They prevent crusting and sealing of the soil surface and moderate soil
temperatures. This allows seed germination to occur more readily. And
they increase infiltration of storm water at the site.
Mulching: A protective blanket of straw or other plant
residue, gravel, or synthetic material applied to the soil surface to
minimize raindrop impact energy and runoff, foster vegetative growth,
reduce evaporation, insulate the soil, and suppress weed growth. Mulch
provides immediate protection, and straw mulch is also typically used
as a matrix for spreading plant seed. Organic mulches such as straw,
wood chips, and shredded bark have been found to be the most effective.
Straw typically requires some kind of tacking, such as liquid emulsions
or netting. Netting may also be needed to hold mulch in place on slopes.
Mats
and blankets are made from a wide variety of organic and synthetic materials
and are useful in establishing grass in swales and waterways, plus they
promote seedling growth.
Erosion Control Products Availability List
The above list was compiled by the Wisconsin Department
of Transportation to highlight advances in erosion mats, soil stabilizers,
tackifiers and silt fences.
Long Term Storm water Management Plan
(Flow Management)
Planning for long term collection and treatment of storm water
runoff early in your site planning process will save dollars and protect
nearby waterways. When writing the long term storm water management
portion of your plan, include the following commonly used practices.
These practices, when used solely, or in combination, will hold back
sediment while allowing runoff water to seep slowly back into the
ground.
Wet Detention Basins
A permanent pool of water with designed dimensions,
inlets, outlets and storage capacity, constructed to collect,
detain, treat and release stormwater runoff. The wet detention
basin is the most common long-term stormwater management practice
used in Wisconsin.
Infiltation Basins and Trenches
Infiltration basins and trenches are used to hold sediment
in place, preventing it from choking out and making wetlands ineffective
or adding to silty deposits in nearby rivers and lakes. These basins
can be very important during larger storms when other storm water management
practices cannot treat or recharge runoff as well.
Grassed Swales
Grassed
swales function by slowing runoff as it comes off an impervious surface
(such as the principal parking area for your business). The grassed
swale can remove sediments and other pollutants and provides some
infiltration into the soil. A drawback, however, is that they can
be ineffective at treating and absorbing runoff during a larger rain
event.
Storm water Wetlands (a.k.a constructed wetlands, artificial
wetlands)
Storm water
wetlands are shallow pools that have wetland plants which remove pollutants
through biological uptake. They are among the most beneficial in removing
pollutants and are aesthetically pleasing, as well. Storm water wetlands
can provide educational and habitat benefits and can be incorporated
into any existing ponds or swales you may already have in place.
Parking Lots - Pavers, Porous Concrete and Bioretention
Islands
Can
your small business design a better parking lot? According to Watershed
Protection Techniques [3(2): 647] "parking lots rank among the
most harmful land uses in any watershed. They not only collect pollutants
that are deposited from the atmosphere, but also accumulate pollutants
that leak, drip or wear off cars."
The article also mentions several design ideas such
as reducing stall sizes, narrowing drive aisles and using inovative
materials and practices such as grid pavers, porous concrete and bioretention
islands (photos below) to absorb storm water.
For more information on better site design oprtions,
please refer to the following article: "The
Benefits of Better Site Design in Commercial Development"-
pdf (680 K) Published by the Center for Watershed Protection (EXIT
DNR)
The above two photos used with permission
from the Center for Watershed Protection.
There are several other long term flow management practices
that can be incorporated into your site design to minimize your impact
to the local watershed and save you money. Please refer to the "Related
Links" (button found along the left margin of most pages within
the Small Business Web Site) topic when you have completed the other
topics.