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Highway agencies manage over six million hectares
(17 million acres) of land in the U.S., approximately
one percent of states with more dense road networks.
[N]
Due to the tendency of the highway system to follow
streams, coastlines and other natural landscape
features, this land is often located within, over,
and/or adjacent to many environmentally sensitive
resources.
All ROWs are managed with the general goal of
providing for safe and reliable transport. In most
all ROW scenarios, active management is needed to
create specific vegetation and related environmental
conditions. [N]
Roadside management objectives vary with the zone
that is being addressed. Typically the gravel shoulders
of roads are maintained as a vegetation-free area,
to allow surface water drainage off the pavement
and into the drainage ways. Off the shoulder, an
operation zone of grass or small trees and shrubs
is maintained through mowing to allow for visibility
of signs and traffic at interchanges and curves.
Large trees are removed for safety in case vehicles
accidentally leave the road. Herbicides are used
very selectively for control of noxious weeds and
sometimes for brush control. A wider buffer zone
beyond that area is commonly maintained in natural
or native, low-maintenance vegetation.
Common objectives for management of the ROW include:
- Managing the immediate shoulder for use as a
recontrol zone for errant vehicles and to inhibit
weeds from growing into the pavement.
- Preserving sight distances for reading signs
and for cornering.
- Offering space for utilities.
- Screening on-coming traffic on divided highways.
- Maintaining slope stability, encouraging drainage
of water off the roadway, protecting water quality,
protecting habitat for wildlife and preserving
or restoring native plant communities.
- Maintaining open space, green corridors, or
a refuge for biodiversity.
- Protecting roadside areas against infestation
and spread of noxious weeds.
- Keeping vegetation back from the edge of the
road to improve visibility of wildlife and reduce
chance of road kill.
- Providing on-site area for wetland mitigation.
This chapter focuses on non-vegetative environmental
stewardship practices for management of the ROW. |
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| 10.1. Environmental
Enhancement Practices and Partnership Efforts |
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| 10.1.1
Water Quality Retrofit Programs |
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Most DOTs have developed or utilize existing design
manuals for runoff control and stormwater quality.
Increasingly, DOTs have to decide where stormwater
quality retrofits may be sufficiently valuable to implement,
and in what order these investments should be prioritized.
In addition to extensive design guidance available
in both manual and on-line formats, a number of BMP
selection and evaluation systems are emerging. NCHRP
25-20(01) " Evaluation of Best Management Practices
for Highway Runoff Control" is designing a BMP
effectiveness and evaluation system that will be available
in late 2004.
MDSHA's Water Quality
Improvement and Retrofit Program
MDSHA's NPDES program was implemented as part of
mandated EPA regulations; however, the program's many
activities have exceeded the regulatory requirements
due to MDSHA's environmental policy to go beyond the
basics and explore new ways to implement environmental
stewardship in the context of the sensitive Chesapeake
Bay Watershed. The agency leadership and staff have
become very active in advancing the cause of the environmental
protection through technology development and enhancement.
Funds have been provided and partnerships have been
forged to leverage the state dollars and maximize the
best management practices (BMPs) at an unprecedented
level.
As part of the agency's environmental quality improvement
efforts, MDSHA has implemented a very structured improvement
program for the 1,500 stormwater management facilities
owned by MDSHA, with inspection teams of trained staff
who identify further environmental improvements that
can be made. MDSHA has complimented this work by mapping
the entire state for opportunities for retrofitting
BMPs, for pollution prevention and stream restoration
beyond requirements, and for development of a plan
for systematic implementation of those improvements.
The grade-based rating system for stormwater management
facilities include an inventory, database, and photo
record of all facilities statewide and their maintenance
status. Under the rating system, those graded A or
B are considered functionally adequate. As of late
2003, between 73 and 75 percent of MDSHA stormwater
were functionally adequate (A=everything fine, working
fine, no maintenance required, B= minor maintenance,
need mowing or trash removal), leaving approximately
25 percent needing maintenance or retrofitting to achieve
functional adequacy. MDSHA aims to have 80 percent
or more of their stormwater management facilities rated
functionally adequate by 2006, and 95 percent of facilities
by 2010.
With continuous improvement as an inherent strategy,
the NPDES team has accomplished many major goals since
its inception in 1999:
- Developed NPDES Strategic and Timeline Plan to
guide the overall implementation effort.
- Developed several pilot projects to streamline
the integration of technology into the field data
collection and analysis process.
- Established field inspection protocols and tools
for data collection, including a Standard Procedures
Manual to streamline the database development, inspection
protocols, and training program for inspecting stormwater
management facilities.
- Established auxiliary programs and management structures
to support the goals of the NPDES program.
- Partnered with several local jurisdictions in their
watershed assessments and restoration efforts – MDSHA
is now partnering on eight different watershed improvement
plans
- Constructed multitude of stormwater retrofit and
enhancement projects throughout Maryland with immediate
benefits to the environment. Many more are underway.
- Developed many cutting edge technologies for stormwater
management such as Low Impact Development (LID) for
highway environment and out-of-kind stormwater mitigation
such as stream restoration.
- Developed the nation's first and only Visual and
Environmental Quality Guidelines for Stormwater Management
Facilities. Implementation of the draft guidelines
already resulted in facilities that benefited from
this context-sensitive approach.
- Developed a Geographic Information System (GIS)
for drainage infrastructure.
- Developed Geographic Information Management System
(GIMS) for systematically inspecting and maintaining
the performance of stormwater management facilities.
- Initiated efforts to develop new state-of-the-art
BMP remediation technology.
- Developed a work delivery system using operating
and capital programs.
- Developed a flow chart for SWM facility remediation
action along with cash flow estimates.
- Developed a budgetary cash-flow estimation system
with the help of pilot projects.
- Developed training for designers on stormwater
management based on data found in the inspection program.
- Performed Discharge Characterization of stormwater
to analyze quality of highway runoff.
- Prepared a report on MDSHA's on-going Public Education
and Outreach Programs and initiated new efforts (Environmental
Responsibility Booklet, Cable-broadcast video, informational
presentations).
- Established Pollution Prevention Teams at all 35
MDSHA Maintenance Facilities to implement the Stormwater
Pollution Prevention Plan in an environmentally responsible
manner – includes pollution prevention training
to personnel.
- Customized pollution prevention plans and strategic
retrofit plans for all MDSHA maintenance facilities
to systematically upgrade them to perform at an environmentally
acceptable level.
- Initiated technology transfer and guidance to other
Maryland Department of Transportation (MDOT) modals.
The Managing for Results (MFR) portion of MDSHA's
business and stewardship plan is being used to measure
the progress and success of the NPDES program and define
timelines and milestones for the numerous elements
of the program. Using the MFR approach, progress is
measured every month for each of the major elements,
and every six months for all the elements of the program.
An example of this is the tracking of the required
number of source identification efforts that needed
to be completed: The strategic plan as well as the
MFR goals called for measurable completion of work
in specified counties by a prescribed date. Another
example is the stormwater management retrofits that
needed to be completed by December 2003. The retrofit
completion progress was tracked every month and new
strategies were developed continuously. As a result,
this requirement was exceeded by 300 percent. Individual
projects, such as watershed retrofits, stormwater improvements
and watershed partnerships that are generated as a
part of the program are managed using MS Project and
milestone reviews.
For maintenance facilities, the discharge sampling
of the outfalls is a direct method for measurement
of success, which is defined based on state and federal
requirements. As a stewardship measure, MDSHA tracks
implementation of strategic upgrades to the facilities
identified during the pollution prevention plan development
and needed changes in systems identified by the independent
inspection program.
Charts are developed for all the major programs to
visually demonstrate successes and progress. Once a
year, an annual report summarizing all the activities,
including compliance with the NPDES program is prepared
and submitted for review to the Maryland Department
of the Environment (MDE). So far, every report was
thoroughly reviewed and approved by MDE, which means
MDSHA remains in compliance and is actually being commended
for showing stewardship by exceeding the permit requirements.
A copy of the recent annual report is attached.
Outfall Categorization
and Improvement at Florida and Washington State DOTs
In the late 1990s WSDOT and FDOT developed systems
for categorizing and improving outfalls.[N]
In the case of WSDOT, assessing which projects provide
the best return on investment in terms of environmental
effectiveness and pollution reduction. WSDOT's system
included a condition indexing methodology and support
program that enables users to quickly evaluate and
compare projects and generate benefit-cost ratios for
projects. [N]
Further information on outfall improvements is available
in descriptions of WSDOT's program, as well as that
of Oregon DOT, in section 3.5, Culverts and Fish Passage.
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| 10.1.2
Wetland Enhancement |
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| PennDOT Staff
Partner to Enhance Local Wetlands
PennDOT construction and maintenance workers are
involved in a pilot program to improve eight wetlands
in the state's District 9 territory. In 1995, the six-county
region was chosen as the lead for PennDOT's wetland
banking program to help save the state's natural resources.
Working with several organizations — including
EPA, the Army Corps of Engineers and FHWA— PennDOT
and the agencies are identifying wetland enhancement
sites, some of which may serve as compensation for
past and future wetland impacts. The largest restoration
area thus far is a 40-acre site prepared by PennDOT
staff. In the summer of 2000, PennDOT workers, with
assistance from the state's game commission, removed
all of the drains and constructed berms to hold in
water. Workers planted trees, warm-season grasses and
thick, shoulder-high shrubs and brush to attract wildlife.
The game commission donated bird, duck and bat "boxes" (houses).
Ducks, pheasants, shorebirds, turtles, deer, muskrats
and other species are flourishing in restoration area
and predators such as coyotes, foxes, and an assortment
of snakes have returned. The project cost less than
$3,500 per acre to complete; the agency estimated the
project would have cost an extra $1.4 million if a
contractor had been assigned to do the work, as $100,000
per acre is a going price. Schools became involved
in the planting, saving taxpayer dollars, and students
return to the area on field trips.[N]
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| 10.1.3
Terrestrial Habitat Enhancement |
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Native habitats and populations of native cavity
nesting birds have been in long-term decline across
the country. Loss of suitable nesting sites and competition
from non-native birds are the major factors in these
population declines. Some DOTs are taking this problem
on by trying to enhance the habitat under DOT ownership.
These extend from large-scale efforts to help state
resource agencies and the governor's office implement
greenway plans in Maryland, Florida, and Pennsylvania,
to DOTs placing nesting platforms for ospreys in the
right-of-way.
NYSDOT's Guidance
for Placing Nest Boxes in ROW
NYSDOT has estimated that the agency owns and maintains
approximately one percent of the state's land area
and thus that the DOT has the potential to enhance
nesting opportunities for native cavity nesting birds
through well-considered design and placement of nest
boxes. Nest boxes must be of the appropriate type,
placed in suitable habitat and monitored on a regular
basis during the nesting season, as failure to consider
these factors can result in inadvertently enhancing
nesting opportunities for non-native birds and further
erosion of the ecological niches of native species.
NYSDOT developed a bulletin on Nest
Boxes for Native Cavity Nesting Birds that provides
basic information and recommendations regarding the
proper use of nest boxes on and adjacent to NYSDOT
property. The guidance provides Attachment
A: Reference and Attachment
B: Internet Sites for Nesting Box Designs.
NYSDOT Region 6 environmental and maintenance staff
developed a program that involves a federally licensed
bird bander and volunteers to manage a roadside trail
of 15 artificial nest boxes. NYSDOT maintenance workers
constructed nest boxes for the American Kestrel and
installed them on the support posts of existing large
expressway signs. Environmental staff and volunteers
regularly monitor the boxes and NYSDEC biologists band
the hatchling kestrels to collect scientific information.
DOT Bat Boxes
Bat roost enhancement projects for roadways can often
be conducted onsite. Commercially produced bat houses
are available that can accommodate up to tens of thousands
of bats. Retrofitting options for bridges are discussed
in section 7.2, Avoiding and Minimizing Impacts to
Fish and Wildlife and Enhancing Habitat
Best practices for constructing or buying bat houses
are outlined below, excerpted and summarized from The
Bat House Builder's Handbook, based on 12 years
of bat house research conducted across the U.S, Canada,
and the Caribbean.[N]
- Design ― All bat houses should be
at least 2 feet tall, have chambers at least 20 inches
tall and 14 inches wide, and have a landing area extending
below the entrance at least 3 to 6 inches (some houses
feature recessed partitions that offer landing space
inside). Taller and wider houses are even better.
Rocket boxes should be at least 3 feet tall and have
at least 12 inches of linear roost space. Most bat
houses have one to four roosting chambers-the more
the better. Roost partitions should be carefully spaced
3/4 to 1 inch apart. All partitions and landing areas
should be roughened. Wood surfaces can be scratched
or grooved horizontally, at roughly 1/4- to 1/2-inch
intervals, or covered with durable square, plastic
mesh (1/8 or 1/4 inch mesh). Include vents approximately
6 inches from the bottom of all houses 24 to 32 inches
tall where average July high temperatures are 85º F
or above. Front vents are as long as a house is wide,
side vents 6 inches tall by 1/2 inch wide. Houses
36 inches tall or taller should have vents approximately
10 to 12 inches from the bottom.
- Construction―For wooden houses, a
combination of exterior plywood (ACX, BCX, or T1-11
grade) and cedar is best. Plywood for bat house exteriors
should be ½-inch thick or greater and have
at least four plies. Do not use pressure-treated wood.
Any screws, hardware or staples used must be exterior
grade (galvanized, coated, stainless, etc). To increase
longevity, use screws rather than nails. Caulk all
seams, especially around the roof. Alternative materials,
such as plastic or fiber-cement board, may last longer
and require less maintenance.
- Wood Treatment―For the exterior, apply
three coats of exterior grade, water-based paint or
stain. Available observations suggest that color should
be black where average high temperatures in July are
less than 85º F, dark colors (such as dark brown
or dark gray) where they are 85 to 95° F, medium
colors where they are 95 to 100º F and white
or light colors where they exceed 100º F. Much
depends upon amount of sun exposure; adjust to darker
colors for less sun. For the interior, use two coats
dark, exterior grade, water-based stain. Apply stain
after creating scratches or grooves or prior to stapling
plastic mesh. Paint fills grooves, making them unusable.
Darker colored bat houses are recommended in northern
climes.
- Sun Exposure― Houses where high temperatures
in July average 80º F or less, should receive
at least 10 hours of sun; more is better. At least
six hours of direct daily sun are recommended for
all bat houses where daily high temperatures in July
average less than 100º F. Full, all-day sun is
often successful in all but the hottest climates.
To create favorable conditions for maternity colonies
in summer, internal bat house temperatures should
stay between 80º F and 100º F as long as
possible.
- Habitat―Most nursery colonies of bats
choose roosts within 1/4 mile of water, preferably
a stream, river or lake. Greatest bat house success
has been achieved in areas of diverse habitat, especially
where there is a mixture of varied agricultural use
and natural vegetation. Bat houses are most likely
to succeed in regions where bats are already attempting
to live in buildings.
- Mounting―Bat houses should be mounted
on buildings or poles. Houses mounted on trees or
metal sidings are seldom used. Wooden, brick, or stone
buildings with proper solar exposure are excellent
choices, and locations under the eaves often are successful.
Single-chamber houses work best when mounted on buildings.
Mounting two bat houses back to back on poles is ideal
(face one house north, the other south). Place houses
3/4 inch apart and cover both with a galvanized metal
roof to protect the center roosting space from rain.
All bat houses should be mounted at least 12 feet
above ground; 15 to 20 feet is better. Bat houses
should not be lit by bright lights.
- Protection from Predators―Houses mounted
on sides of buildings or on metal poles provide the
best protection from predators. Metal predator guards
may be helpful, especially on wooden poles. Bat houses
may be found more quickly if located along forest
or water edges where bats tend to fly; however, they
should be placed at least 20 to 25 feet from the nearest
tree branches, wires or other potential perches for
aerial predators.
- Avoiding Use by Other Species and Waste Accumulation―Wasps
can be a problem before bats fully occupy a house.
Use of 3/4-inch roosting spaces reduces wasp use.
If nests accumulate, they should be removed in late
winter or early spring before either wasps or bats
return. Open-bottom houses greatly reduce problems
with birds, mice, squirrels or parasites. Furthermore,
guano does not accumulate inside.
- Timing―Bat houses can be installed
at any time of the year, but are more likely to be
used during their first summer if installed before
the bats return in spring. When using bat houses in
conjunction with excluding a colony from a building,
install the bat houses at least two to six weeks before
the actual eviction, if possible.
- Importance of Local Experimentation―It
is best to test for local needs before putting up
more than three to six houses, especially comparing
those of different darkness and sun exposure.
DOTs have contributed to bat conservation and recovery
through assisting mine gating efforts. Sealing abandoned
mines without first evaluating their importance to
bats is one of greatest threats to North American bat
populations, which use caves as hibernacula.
Bridge Related Enhancements
Techniques to minimize construction and maintenance
impacts on bats are discussed at length in Chapter
7 on Practices in Bridge Construction and Maintenance.
Impacts to birds and practices to benefit birds are
discussed in that section as well, to a lesser extent.
Practices that benefit ground-nesting birds are discussed
in Chapter 9, in particular, those related to Reduced
Mowing in section 9.5.
Reduced Mowing at
DOTs to Conserve Resources, Bird Habitat, and Native
Species
As part of their Integrated Roadside Vegetation Management
or other conservation plans Colorado DOT, Iowa DOT,
Mn/DOT, WisDOT, NYSDOT, and Utah DOT have implemented
mowing reductions to conserve resources and benefit
native species. In most cases, these programs preserve
habitat for ground-nesting birds and other native species
by limiting mowing to one mower width along the roadway.
For more information see Chapter 9 of this report.
Iowa DOT Roadside
Native Species Restoration Program in Maintenance
While many state DOTs have begun to mandate use of
native species when revegetating construction sites,
Iowa DOT has extended their landmark IRVM program to
revegetate approximately 2,200 acres annually of targeted
roadside areas not connected to any construction projects.
Another 3,200 acres of roadside on construction sites
are seeded annually with native grasses and forbs.
The state's transportation commission actively supports
the program.
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| 10.1.4
Identifying and Implementing Aquatic Connectivity
(Fish Passage) Improvements |
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| Oregon DOT Culvert
Retrofit and Replacement Program Agreement
In 2001, the Oregon Department of Transportation
(ODOT) and the state Department of Fish and Wildlife
(ODFW) signed a Memorandum of Understanding (MOU) that
repairing or modifying ODOT-maintained culverts is
a priority for the agencies that will take decades
to resolve. The ODFW completed culvert inventories
for the entire state of Oregon in 1999 and found that
96 percent of the barriers identified were culverts
associated with road crossings. The project also identified
high priority culverts for fish passage remediation.
ODOT has an ongoing program of culvert installation
and maintenance, with the goal of making all ODOT culverts
passable to fish. After research monitoring results
demonstrated the effectiveness of baffle and weir designs
in culverts, ODOT modified their culvert replacement
programs to use these designs, significantly reducing
the cost of improving fish passage at ODOT culverts.
The designs improve fish passage by slowing water velocity
and raising stream elevations to reduce entry jump
heights or backwater culvert outlets. Use of retrofit
designs are allowing culverts that are otherwise in
good physical condition to be retrofitted until their
service integrity is compromised, at which time they
will be replaced with designs that more fully meet
fish passage criteria and standards. Use of retrofits
allows many more culverts to be remediated each year,
increasing the scope and pace of ODOT's contribution
to salmon recovery in Oregon. The baffle and weir retrofits
provide ODOT an alternative to fish ladders, which
have become increasingly problematic for ODOT from
a maintenance standpoint.
According to the MOU, ODOT will continue internal
education regarding the needs and requirement of fish
passage and prioritize its resources and culvert modification
needs on an annual basis, demonstrating good faith
in addressing culvert passage problems. On replacement
culvert projects, ODOT will strive to simulate a natural
stream and will determine if changes in culverts result
in flows detrimental to fish passage. ODFW is supporting
ODOT's efforts by providing the master inventory of
culverts that do not provide adequate passage, along
with technical assistance on educational activities,
design, and construction techniques.
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| 10.1.5
Installation/Improvement of Public Fishing Access |
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| NYSDOT Public
Access Enhancement and Partnership
NYSDOT has been exploring and extending the highway
system's larger role of connecting people and places
of interest. Looking out for these needs, the NYSDOT
Niagara County maintenance staff took the lead in forming
a partnership with local business, the NYS Office of
Parks Recreation and Historic Preservation and the
New York State Department of Environment Control, to
provide a public fishing access site and picnic area
at a popular salmon and trout stream — Keg Creek.
Anglers formerly parked haphazardly along the state
highway and traversed a very steep, slippery and dangerous
ravine to fish for Lake Ontario's world famous migrating
trout and salmon. This created a safety problem for
passing motorists and for the anglers themselves. NYSDOT
maintenance crews designed and constructed a paved
parking area, a series of wooden stairs and a picnic
area with lumber donated by a local company and tables
donated by the State Parks Department.[N]
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| 10.1.6
Extending Highway Maintenance Activities to Bicycle
Trails |
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Under the "Livable Delaware" Plan, Delaware
DOT is extending Highway Operations Maintenance Policy
to care for an increasing number of bicycle paths
and sidewalks. Until the recent past, there have been
relatively few bicycle paths and sidewalks within
the state's right-of-way. Public input was relatively
minor, requests for service were handled individually,
and actions were very specific to satisfy only the
scope of the complaint being responded to.
DelDOT assessed the current situation and is implementing
the following practices for bicycle paths: [N]
- For those bicycle paths which have been, or will
be created within the paved surface of the roadway,
and designated by paint striping, cleaning and repair
of these facilities will be accomplished within the
existing established procedures and policies governing
highway sweeping and pot hole repair.
- Develop policy guiding frequency of cleaning and
standards defining an acceptable level of maintenance
where bicycle paths are constructed as separate,
stand-alone facilities.
- Obtain specialized equipment not currently in
the Department's inventory or contracted services
to properly maintain separate paths. Existing equipment
is designed for roadway service and is too large
and heavy to be utilized on stand-alone bikeways
without damaging the physical structure of the path.
DelDOT noted that sidewalks located within the state's
right-of-way along maintenance numbered roadways outside
of municipal boundaries have long been given minimal
attention, and that no standards or policies define
frequency of cleaning or serviceability. Where failures
occur, they are not addressed unless significant public
input is received. DelDOT has formed a committee to
develop overall maintenance policies for sidewalks
outside of subdivisions in general.
The committees for bicycle paths and sidewalks were
appointed by the Directors of Highway Operations,
Pre-Construction, and Planning since planning and
design considerations must be considered in development
of an adequate and rational maintenance policy; e.g.,
where a sidewalk and/or bicycle path is placed relative
to the roadway will have significant impact on the
ease of cleaning and maintaining the facility, requiring
that these long-term activities be fully considered
in the project development phase. The Delaware Bicycle
Council, County governments, and numerous municipalities
are feeding into the process.
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to Section 10.2 » |
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