Attachment_0011_-_BMP_Handbook.pdf

BMP Handbook Best Management Practices for Idaho Rural Road Maintenance

Researched and Compiled by Stacy Smith

August 2005

Funding provided by:

Idaho Technology Transfer (T2) Center University of Idaho

Federal Highway Administration

Idaho Department of Environmental Quality

Idaho Technology Transfer (T2) Center University of Idaho

Engineering Physics Building 115F PO Box 440911

Moscow, ID 83844-0911

Phone: 800-393-7289 (Idaho only) 208-885-4334

Fax: 208-885-2877 E-mail: idahot2@uidaho.edu

Web site: http://www.webs1.uidaho.edu/idahot2/

TABLE OF CONTENTS

Introduction Project History Manual Objectives Considerations for Rural Road Maintenance How to Use This Manual Acknowledgements

BMP Checklist

Chapter 1 - Road Maintenance Activities

1) Grading

2) Hauling & placement of materials

3) Bank and slope stabilization

4) Ditching

5) Noxious Weed Control

6) Road Stabilization

7) Vegetation Management

8) Dust Control

9) Winter Maintenance

Chapter 2 – Drainage & Stream Crossings

1) Bridges

2) Culverts

3) Cross Drains

4) Injection Wells

5) Paved Dips

6) Ditches

7) Vegetative Filter Strips

Chapter 3 – Erosion Control Methods

1) Basic erosion concepts and concerns

2) Erosion control devices (BMPs)

1) Temporary Erosion Control Devices

2) Permanent Erosion Control Devices

Reference Materials Acronyms and definitions References

Appendices Appendix A: Agency and Permitting Contact Information Appendix B: Permits and Regulations

1) Clean Water Act (CWA)

2) Endangered Species Act (ESA):

3) Emergency Stream Channel Alteration Permit (IDWR) ..100

4) County-specific permits and regulations:

Appendix C: Fish Life Cycle Histories as Related to Instream Work Projects Appendix D: Grants and Additional Funding Opportunities

Introduction

Project History This manual and the associated training programs resulted from a need for collaboration identified by the Bureau of Land Management (BLM), Forest Service, Idaho Department of Environmental Quality (DEQ) and Custer County Road and Bridge. There are numerous environmental problems in Idaho, such as accelerated erosion, sediment pollution, the elimination and degradation of fish and wildlife habitats and populations, dust pollution, and chemical pollution. Many factors contribute to these problems, including

- Development

- Property owners

- Agricultural practices

- Weather events

- Cattle grazing

- Timber harvest

- Roads

• Maintenance Grading, ditches and cluverts

• Construction Runoff, erosion and unstable soils

Several environmental laws and regulations affect the work of road maintenance personnel on a daily basis. Compliance with these regulations is important, not only because it is required, but because compliance helps reduce sedimentation and other negative impacts that road maintenance can have on the environment. As stewards of the resources we enjoy as hunters, fishermen & outdoor enthusiasts we must work to preserve the environment and water quality.

Manual Objectives In providing leadership and support to the local highway jurisdictions in the state of Idaho, the Idaho Technology Transfer (T2) Center created this manual to assist the jurisdictions in complying with local, state and federal regulations as well as using environmentally sensitive maintenance practices on rural roads throughtout the state.

The main objective of this manual is to recommend maintenance operations and procedures for maintenance (Best Management Practices or BMPs) that are not only reasonable, but also effectively reduce erosion and sedimentation and lessen environmental impacts that can occur with normal maintenance activities of local highway jurisdictions and other agencies who maintain the rural roads in Idaho.

Collaboration between agencies will also help prevent and address these environmental problems, help all jurisdictions and agencies to comply with the laws and regulations and hopefully result in some cooperative working relationships and cost-sharing opportunities.

Introduction 1

Considerations for Rural Road Maintenance Many important topics and issues are addressed in this manual with feasible and acceptable solutions provided for each one. Some things to consider before doing any maintenance work;

• Inspect all work and projects, and drainage system components to determine that they are functioning properly and to ensure that problems are corrected as soon as they develop; prevent future problems before they arise.

• Identify the environmental protection requirements associated with road maintenance. Consider the protection and enhancement of watersheds, fish-producing streams, wildlife habitat, key wildlife migration and linkage areas, and scenic resources as well as the control and reduction of erosion when planning all maintenance practices.

• Erosion and the resulting sediments can cause damage to the environment and water quality. Erosion can also cause additional maintenance and costly repairs. Through proper maintenance, costs can be reduced while decreasing impacts on the environment.

• Stormwater runoff from ground-disturbing activities or construction activities can have a significant impact on water quality. As stormwater flows over a construction site or disturbed soil, it picks up pollutants such as sediment, debris, and chemicals.

Polluted stormwater runoff can harm or kill fish and other wildlife.

Sedimentation can destroy aquatic habitat and high volumes of runoff can cause stream bank erosion.

• Ensure proper drainage during maintenance. Get water off of the road quickly and often to reduce its velocity and destructive forces.

When possible avoid public use of roads when they are excessively wet to help reduce annual maintenance.

• Focus on the heavily used roads and the worst problems first. By reducing maintenance on roads with fewer problems, more time and resources can go toward repairing damaged or degraded road segments reducing future, more complex maintenance efforts.

• Timing of maintenance work is crucial for many of the practices to be effective, long-lasting and environmentally friendly. For example:

- Major ground disturbing events, such as culvert replacement, should take place during the dry season.

2 BMP Handbook

- Organize the maintenance schedule with bare-ground weed treatments in mind (i.e., grade before spraying pesticides).

- Do not do work near streams during spawning or migration periods for fish.

• Consult with a representative from the Natural Resources Conservation Service (NRCS), Conservation District, Idaho Fish and Game or Tribal Fisheries Department (Appendix A) when working on any hydrology or fish passage project. These agencies can help to design and implement the project in a way that is safe for the fish and that will belong-lasting.

How to Use This Manual There are several very different and very important parts of this manual;

below is a description of each section and how to utilize its features.

For your convenience this manual is also available online at:

http://www.webs1.uidaho.edu/idahot2.

BMP Checklist Because every maintenance project is different it is important to consider all aspects of the site before any work begins. This checklist will help to evaluate the site conditions and chose an effective BMP or maintenance procedure for that area. Make copies of pages 8-11 and fill out Table 1 before beginning any maintenance work.

Chapter 1 – Road Maintenance Activities Chapter 1 describes ways of conducting routine road maintenance activities that will help reduce erosion and sedimentation and have less impact on the environment.

Chapter 2 – Drainage and Stream Crossings Chapter 2 covers maintenance and considerations for drainage systems and stream crossings.

Chapter 3 – Erosion Control Methods Chapter 3 lists, describes and depicts numerous solutions for controlling erosion resulting from rural road maintenance or other natural disturbances. The key steps to erosion control are to slow the flow of runoff on roads and slopes, maintain properly functioning drainage systems and install erosion control devices where necessary.

Introduction 3

Reference Materials:

Acronyms and Definitions

This section will be helpful for looking up acronyms used in the manual as well as any words that may be unfamiliar.

References This section lists all sources used in the manual both for pictures and figures, as well as the text.

Appendices:

Appendix A: Agency and Permitting Contact Information

Appendix A is referred to throughout the manual because is contains contact information for all state and federal regulatory and resource management agencies, tribal and local agencies. This section should prove very useful for implementing these BMPs and acquiring any necessary permits

Appendix B: Permits and Regulations Appendix B describes the permits and regulations applicable to rural road maintenance. There are links to online permit applications and descriptions of when applications are required. Contact information for each permitting agency can be found in Appendix A.

Appendix C: Fish Life Cycle Histories as Related to Instream Work Projects

This section lists mainstem rivers and their tributaries for the entire state of Idaho and when work is permitted in and around those streams based on fish migration and spawning patterns. In addition to these tables, it is advised to contact the regional Idaho Fish and Game or Tribal fisheries biologist regarding the planned work and the best way to accomplish it without harming the water quality, fish or habitat.

Appendix D: Grants and Additional Funding Opportunities In Appendix D you will find a few resources for additional funding.

Purchasing, and installing some of the BMPs in this manual can be expensive, but there are several agencies around the state that are willing to work with other agencies to install new culverts and enhance the roadsides. It would be very beneficial for the local highway jurisdictions to take advantage of these extra funds and work with the state and federal agencies to implement new practices.

4 BMP Handbook

Acknowledgements The Idaho Technology Transfer (T2) Center would like to thank the following individuals and agencies for the time, energy and resources they provided to make this manual a reality. This project started several years ago, but without those named below, the manual would still be just a concept.

Focus Group Members Bill Kinghorn, Retired Assistant Road Supervisor, Bannock County Highway Department Steve Lusk, Road Foreman, Power County Highway District Randy Murray, Public Works Director, Shoshone County Butch Renshaw, Road Foreman, Kamiah Highway District Jim Sugden, Supervisor, Custer County Road and Bridge

BMP Roads Committee Members Bill Nance, Idaho Transportation Department Bill Stewart, Environmental Protection Agency Byron Keely, Local Highway Technical Assistance Council Craig Foss, Idaho Department of Lands Dan Reinkensmeyer, USFWS - Snake River Fish and Wildlife Office Debbie Artimez, NOAA Fisheries Doug Abderhalden, Idaho Department of Environmental Quality Emmit Taylor, Jr., Nez Perce Tribe Department of Fisheries Resource Management – Watershed Division Erv Ballou, Idaho Department of Water Resources Greg Martinez, U.S. Army Corps of Engineers Gregg Servheen, Idaho Department of Fish and Game Jim Colla, Idaho Department of Lands Joe Haynes, Local Highway Technical Assistance Council Karl Gebhardt, Bureau of Land Management Ken Heffner, USDA Forest Service Leigh Woodruff, Environmental Protection Agency Mark Robertson, USFWS - Snake River Fish and Wildlife Office Matt Voile, Idaho State Department. of Agriculture Misha Vakoc, Environmental Protection Agency Nicholle Rowell, U.S. Army Corps of Engineers Nikki Leonard, NOAA Fisheries Richard Sims, Idaho State Department of Agriculture Rick Huddleston, Idaho Department of Environmental Quality Rob Sampson, USDA-Natural Resources Conservation Service Tim Kennedy, Idaho Department of Lands T. J. Clifford, USDA Forest Service - Boise National Forest

Introduction 5

Editing and Graphics Editing: Judy LaLonde, National Institute for Advanced Transportation Technology (NIATT) Graphics: Niklas Aleksich

Funding for this project was provided by:

Federal Highway Administration (FHWA)

• Environmental Streamlining Grant

Idaho Department of Environmental Quality (DEQ)

• 319 Grant

6 BMP Handbook

Best Management Practices (BMP) Checklist

Every maintenance project is different. When choosing maintenance and erosion control methods, be sure to evaluate the site conditions, environmental factors, economics, and desired service life by using the Best Management Practices (BMP) Checklist below.

Before beginning any road maintenance evaluate the site conditions by filling in the boxes in Table 1 – Maintenance Activity Information. If the answers indicate the potential for runoff, erosion or impacts to a stream or water body – please see Table 2 - Recommended BMPs for Road Maintenance Activities.

For more information on any of the listed BMPs, see Chapter 3 - Erosion Control Methods.

Sample responses for Table 1:

Soil Type: Stable, somewhat stable or erodable.

Weather Forecast: Determine the chance of precipitation before, during and after a project.

Size of Area: Small, medium, or large.

Steepness of Area: Flat, slight incline, steep or very steep.

Stream or Wetland: Is there a stream (intermittent or perennial) or wetland on or near the project site?

Where does road drainage flow: Into a storm drain, vegetative filter strip, into a stream or wetland?

Fish in stream: If there is a stream nearby consider the impacts the maintenance work could have on fish and other aquatic species in the area and downstream.

BMP Checklist 7

Ta bl e

M ai nt en an ce A ct iv ity In fo rm at io n

Si te

E va lu at io n

M A

IN

T

E N

A N

C E

A C

T

IV

IT

Y

IN

F

O R

M A

T

IO

N

S it e E va lu at io n

L o ca ti o n

P ro je ct L ea d

P ro je ct

D at es

D es cr ip ti o n o f A ct iv it y:

C H

E C

K L

IS

T

M ai n te n an ce

A ct iv it y S o il

Ty p e W ea th er

F o re ca st S iz e o f

A re a S te ep n es s o f ar ea S tr ea m o r W et la n d

W h er e d o es r ad d ra in ag e fl o w

F is h in st re am

P er m it s th at m ay b e re q u ir ed

G ra di ng

In w et la nd s or s tr ea m c ha nn el s a C or ps p er m it an d/ or

ID

W R

S tr ea m A lte ra tio n

P er m it

H au lin g an d

P la ci ng

M at er ia ls

C or ps

P er m it an d/ or

Id ah o S tr ea m C ha nn el A lte ra tio n

P er m it

B an k an d S lo pe ta bi liz at io n

C or ps

P er m it an d/ or

Id ah o S tr ea m C ha nn el A lte ra tio n

P er m it

D itc h M ai nt en an ce C or ps

8 BMP Handbook oa d S ta bi liz at io n an d

D us t C on tr ol

N /A

V eg et at io n

M an ag em en t

(r em ov al o f r ip ar ia n ve ge ta tio n ot he r th an b y bu ck et m ay r eq ui re a

C or ps pe rm it)

W in te r

M ai nt en an ce

N /A

In st al lin g E ro si on

C on tr ol

M et ho ds

C or ps

P er m it an d/ or

Id ah o S tr ea m C ha nn el A lte ra tio n

P er m it

D is tu rb in g m or e th an a cr e of la nd

N P

D E

S P er m it

B rid ge a nd c ul ve rt m ai nt en an ce r in st al la tio n

S ee

A pp en di x D fo r ap pr op ria te ti es of y ea r to w or k in o r ne ar s tr ea m s w ith fi sh

BMP Checklist 9

In T ab le b el ow

, l oc at e th e pl an ne d m ai nt en an ce p ro ce du re in th e fir st ro w a nd lo ok fo r g ra y bo xe s i n th at c ol um n to fi nd B

M Ps th w k w el l w ith y ou r p la nn ed m ai nt en an ce

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Ps fo r R oa d M ai nt en an ce A ct iv iti es

R E

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B an k an d S pe ta bi liz at io n

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V eg et at io n

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B en ch in g / S ur fa ou gh en in g

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P

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10 BMP Handbook

F ilt er fa br ic ge ot ex til es

(P

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H an d se ed in g an d H yd ro se ed in g

(P

M ul ch in g (T

Li ve s ta ke s

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S an db ag s (T

S ilt

F en ce

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S tr aw B al e

B ar rie r

(T

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B io gs

(T

BMP Checklist 11

After evaluating the site conditions using Table 1, consider the following based on the requirements and concerns for the site:

1. Acquiring permits can be time consuming, start the process as early as possible.

2. Erodable soils may require extra attention and implementation of erosion control devices (Chapter 3).

3. If heavy rains are predicted consider rescheduling major ground disturbing work or install BMPs to help manage and contain any runoff that may occur during the project.

4. For larger project areas be sure to have enough materials to re-vegetate the area upon project completion.

5. The steeper the slope the faster the runoff and greater potential for erosion.

6. If there is a stream or wetland near the project site or you will be working in the stream channel – you must contact the Army Corps of Engineers and the IDWR to see if a permit is required.

7. See Appendix C to determine if there are limitations to work in or near the stream. Contact the IDFG (Appendix B) if unsure whether or not there are fish in the stream and to check on whether or not there are concerns with threatened, endangered, or sensitive species.

8. Consider threatened and endangered plant and animal species, wetlands, agricultural crops, etc.

12 BMP Handbook

Chapter 1 - Road Maintenance Activities Routine and annual road maintenance activities can have a negative impact on the environment, but they do not have to. The frequency and costs of maintenance activities can be reduced, while at the same time, have a positive effect on air and water quality by following the recommendations below.

*Before beginning a maintenance procedure, operators need to consider the design of the road in order to choose a practice that is operationally sound and environmentally conscious.*

1) Grading Several important factors should be considered when grading dirt and gravel roads. Using these practices will help reduce the number of times a road needs grading, which in turn reduces loss of materials and decreases pollution and sedimentation in the streams and air.

• Avoid grading when a road is in satisfactory condition. Loosening the soil can accelerate erosion and increase noxious weeds.

• Maintain the crown and shape of the road when grading. Proper road shape will help with drainage and a well-built road will maintain its shape if it is well drained. The most effective designs use slopes no greater than those listed in Figure 1.1.

Figure 1.1 Recommended slopes for effective surface water drainage Source: Low-Volume Roads Engineering Best Management Practices Guide.

Road Maintenance Activities 13

• Schedule grading and earthmoving operations to expose the smallest possible area of land for the shortest possible length of time.

• Grade only when proper soil moisture is present--after most runoff has occurred and roads are starting to dry out, usually early to late spring. This reduces the need for grading by allowing for compaction of wet soils rather than filling in holes with dust that may blow or wash away.

• Do not grade or push materials over stream banks. Instead; push them to the center of the road and spread.

• Grading or reshaping road surfaces

- Maintain crown and overall road shape.

- Nothing < 2% or > 6% slope.

- Check cross slope.

- Compact materials with pneumatic and/or steel wheeled roller.

Figure 1.2 An example of a well-graded road with proper crown Source: Gravel Roads Maintenance and Design Manual.

14 BMP Handbook

• When applying aggregates to a graded road

- Use clean (weed-free) gravel and rock.

- Use grader and rake to apply.

- Grader angle will depend on the size of material being spread.

- Compact the aggregate material with a proper roller after it has been cut and repositioned – this will leave a stronger, denser and smoother surface that is easier to maintain.

Figure 1.3 Proper road crown (flat “A” shape) Source: Minnesota LTAP Program presentation.

Dirt & Gravel: 1/2”-3/4” per foot (4-6 inches in 10 feet)

a) Insloping - a road sloped to the inside (Figure 1.4).

- 3-6 % slope.

- Insloping is meant to collect ditch water drainage and direct it to a cross culvert.

- May need culvert inlet and outlet protection (see Chapter 2, Section

2c, page 39).

- Eliminates bank erosion and washouts, if cross drains are of sufficient size.

Figure 1.4 Insloping Source: Minnesota LTAP Program presentation.

Slope: 1/2” - 3/4” minimum per foot

Road Maintenance Activities 15

b) Outsloping – a road sloped to the outside (Figure 1.5)

- 3-6% slope.

- Outsloping is meant to disperse water so there is no erosion.

- Use on gentle grades only (less than 5% or 7%).

- Use on low overland sheet flow conditions.

- Fits natural drainage.

- No ditches or cross pipes needed.

*Outsloping may not be appropriate in areas with more than 5-7% grade, in areas with highly erodable soils or where a stream is just below the road surface.*

Figure 1.5 Outsloping

Slope: 1/2” - 3/4” minimum per foot

Dimensions for outsloping a road. Safety issues should be considered. Source: Minnesota LTAP Program presentation.

Figure 1.6 Super-elevated curve Photographed by Stacy Smith.

16 BMP Handbook

c) Transitions (i.e. bridges, curves, railroad crossings, intersections, etc.)

- Gradually eliminate crown to transitions and back within 100 feet of curves (Figure 1.7).

- Do not direct water flow into stream or water body.

- Eliminate erosion and high flow rates using BMPs from Chapter 3.

- Do not channel water flow on roads; sheet flow has less impact.

Figure 1.7 Proper design for a super-elevated curve Source: Gravel Roads Maintenance and Design Manual.

2) Hauling and placement of materials

- Do not side-cast materials into streams or over edge of banks

(Figure 1.8).

- Haul materials only to an approved site (i.e., pull-outs, with permission from private landowners).

- Do not put materials in streams or wetlands (requires a Corps 404

Permit).

Road Maintenance Activities 17

Figure 1.8 Side-casting

Do not side-cast materials over banks. Sedimentation in streams decreases water quality, alters aquatic habitat and kills fish. Photographed by John Robison, Idaho Conservation League.

3) Bank and slope stabilization Stabilizing the banks of a road immediately after a disturbance (i.e., from a rebuilt section of road, maintenance procedure or erosion from a storm) helps reduce erosion and future maintenance needs.

Flatter slopes give greater stability and result in less erosion and sedimentation; observe and follow existing Do not disturb a stable slope when possible.

- Do not encroach on a stream; avoid all pinching or restrictions.

- Maintain and promote vegetation on slopes for stability, removal can result in bank failure.

- Planting slopes provides long-term soil stabilization, and reduces water velocity and erosive forces.

- Apply re-vegetation, seeding or mulching, using certified weed-free materials when possible to any disturbed areas along roadsides. (For contacts and availability of weed-free materials see Appendix A).

- Surface roughening/grooving (See Chapter 3, page 56).

- Use tracked equipment (disk, tiller, etc.) to put horizontal grooves in bare, sloped soil surface. This helps reduce runoff velocity, improves infiltration and can help establish vegetation.

*For more methods, installation details and examples of bank and slope stabilization, please see Chapter 3 – Erosion Control Methods.*

For information on native plant species, their precipitation requirements and road suitability see the Idaho Transportation Departmentʼs Idaho Roadside Revegetation Handbook at: http://itd.idaho.gov/highways/ops/maintenance/ Manuals/fullVegetationManual.pdf.

18 BMP Handbook

4) Ditching The main function of a ditch is to carry water away from the road. Ditches should be shaped to prevent standing water, install frequent outlets in areas with regular or periodic high volumes of water.

Do not outlet a ditch directly into a stream; use turnouts into roadside vegetative filter strips (see Figure 2.8, page 44).

Ditch shape

- A wider and flatter ditch/channel will help to spread out water flow, slowing velocity (Figure 1.9).

- Shape and line ditches to achieve proper flow velocities to minimize the impact of flow on ditch. Be sure to stabilize channels with higher velocities (Table 3.2, page 66).

- Disturb only the foreslope and flowline of ditches when cleaning (Figures 1.9 and 1.10).

Figure 1.9 Proper ditch shape and structure Source: Minnesota LTAP Program presentation.

Ditch Maintenance

- Clean ditches only when they are not functioning properly (i.e., not keeping water off of the road, filling in with sediments, eroding, and/or require frequent maintenance).

- Keep vegetation intact when possible (Figure 1.10) vegetation acts as a sediment filter, reduces the velocity of the flow and helps hold ditch shape and soil in place.

- Remove small blockages by hand or shovel, rather than with large equipment.

- Clean upgrade ditch sections first or alternating sections of long ditches (work from the top of the hill to the bottom).

Road Maintenance Activities 19

- Do not cut the backslope (Figure 1.10 and 1.11). Avoid undercutting cutbanks and retain bank sloughage when adequate road width remains.

Figure 1.10 Proper and improper ways to clean a ditch Designed by Niklas Aleksich.

Leave vegetation intact when and wherever possible.

Vegetation helps filter out sediments and slow the velocity of runoff.

Figure 1.11 Maintain original width and depth of ditches when cleaning Designed by Niklas Aleksich.

20 BMP Handbook

• Lining a ditch with angular rocks (“rock armor”) will help stabilize ditches and channels from erosion and soil particle movement.

• After ditch maintenance, install temporary erosion protection, such as check dams, biodegradable erosion control blankets or non-biodegradable geotextiles fabrics, until vegetation has a chance to establish (See Chapter 3, Section 2 – Erosion Control Devices).

• Hydroseed, mulch or plant grasses to help maintain shape and filter out sediments from the drainage.

• Reuse topsoil and existing root mass removed during grading processes; place topsoil/sod to the side and replace after grading when possible.

5) Noxious Weed Control Noxious weed control can be expensive and time consuming, but major problems with native plants, agricultural crops and wildlife habitat and forage could develop without proper control.

Some common weeds found around Idaho are diffuse knapweed, spotted knapweed, yellow star thistle, dalmation toadflax and yellow toadflax.

Thirty-six weeds are listed as common in Idaho in the manual Idaho s̓ Noxious Weeds. This excellent guide to identify Idaho s̓ noxious weeds is available for only $5 at http://info.ag.uidaho.edu/noxious-weeds/index.html or Phone: (208) 885-7982 Fax: (208) 885-4648 E-mail: agpubs@uidaho.edu.

A County Weed Control Superintendent can be contacted (Appendix A) for specific information on weed species, the best methods of controlling them, and possibilities for cost-sharing.

There are two main methods of weed control:

1) Bare ground treatments – Used for maintaining a weed and vegetation-free zone along the shoulders. This treatment is generally very successful with only one application per year.

Time of treatment: Fall, late winter or very early spring (depending when the region gets its rains). It is illegal to apply soil herbicides when the soil is frozen because the product could run off the road or frozen surface and into nearby waterbodies or onto untargeted plants.

Application: Soil sterilant herbicides are applied to bare ground Rainfall within 10 to 15 days following application is necessary to

Road Maintenance Activities 21 incorporate herbicide into the soil profile 1-2 inches deep to kill the plant roots. Do not apply if heavy rains are expected.

2) Broadleaf weed control zone herbicide treatments – Kills actively growing broadleaf plant pests (noxious weeds). This treatment is typically much less expensive than soil sterilant treatments, but often requires repeated treatments throughout the growing season. If the weeds in the area are classified as “noxious,” the County Weed Control Superintendent may require re-treatment to prevent seed spread.

Time of treatment: Begin spray application in the spring when plant pests appear, repeat as needed. Some species exhibit a perennial growth habit and will re-appear in the fall – when they are most successfully treated.

Application: Use along roadsides that have not been treated with soil sterilants. Spray weed control herbicides along roadsides, directly on target species.

Weed Control Chemical Application:

Apply chemical controls at manufacturers ̓specified rates and in accordance with all federal, state, and local regulations governing their use. Chemical products must be stored, handled, and disposed of in accordance with all applicable regulations and department policies. The Idaho State Department of Agriculture regulates chemical control of vegetation, contact the regional office with questions or concerns (Appendix A).

- Do not spray when it is windy because the chemical can drift and damage crops or other nearby plants.

- Do not spray when high temperatures are predicted to avoid evaporation and waste of chemicals – check the product label for maximum recommended temperatures.

- Many plants are usually done growing and producing seeds by the time temperatures reach 70 or 80 degrees, making spray in these temperatures ineffective.

- Be aware of and avoid threatened or endangered plant species.

- Use caution when treating weeds near streams to keep herbicide drift out of the stream.

6) Road Stabilization Road stabilizing materials obtain the desired moisture, increase cohesion, produce a cementing action, and act as a waterproofing agent. Stabilization decreases the loss of materials and the need for road maintenance.

22 BMP Handbook

The best method for achieving road stabilization is:

- Uniformly crushing, pulverizing, and blending the road materials.

- Adding a stabilizing material.

- Laying graded materials back down with proper crown and compacting by proper rolling.

Common Stabilization Materials

• Calcium chloride

• Magnesium chloride

• Resins

• Lime

• Cement

• Asphalt

• Fly Ash

Application

- Use caution and care when applying stabilization materials to road surfaces.

- Ensure spray is on road surface only.

- Stop spray over bridges to avoid chemicals getting into streams.

7) Vegetation Management Maintain vegetation whenever possible along streams, roads and ditches to help stabilize soils and banks and to help reduce erosion and sedimentation.

Ground cover is the most important factor in terms of preventing erosion.

Vegetative cover offers a number of important advantages, including reducing raindrop impact, slowing runoff velocity, helping to absorb water, and holding soil in place. Elimination of vegetation effectively decreases the soils ability to hold and process water and may result in a decrease in groundwater recharge.

Best Management Practices Advantages of leaving roadside vegetationintact and shading road surface

Select structurally sound trees individually

Retains road moisture (reduces dust) Remove wounded trees

Reduces growth of colonizer species Remove colonizer species

Encourages herbaceous plant growth

Leave strong, slow-growing deep-rooted trees (climax species)

Road Maintenance Activities 23

a) Revegetation after site disturbance To prevent and reduce sediments running off of a disturbed area, consider revegetation for all areas with exposed soil. Native grasses, shrubs and trees are available from vendors throughout the state. For assistance in planning and executing the revegetation of an area and cost-sharing opportunities, contact the local Conservation District (NRCS), Forest Service, BLM or Tribal Natural Resources Department (Appendix A).

For information on native plant species, their precipitation requirements and road suitability see the Idaho Transportation Departmentʼs Idaho Roadside Revegetation Handbook at: http://itd.idaho.gov/highways/ ops/maintenance/Manuals/fullVegetationManual.pdf

Figure 1.12 Revegetation and erosion control methods

Depiction of a variety of re-vegetation and erosion control methods that should be considered after disturbing an area alongside a road. Source: Low-Volume Roads Engineering Best Management Practices Guide.

24 BMP Handbook dees ssarG hclum dna etagerggA decafrus debdaor

Old landing or construction work area

Sediment catchment basin

Logging slash or woody material spread over the area

Various erosion control ground covers include seeding and straw mulch, grasses and other mulch, vegetation, rock, slash, chips, and leaves.

Deep rooted vegetation for slope stabilization

Woody slash

Grasses

Aggregate road surfacing or scarification, seed and mulch for closed roads

Vegetative ground cover

Grasses or other vegetation

Cross-section

Perspective View

Vegetative contour hedgerow or wattles

b) Removal and maintenance of existing vegetation

*Leave native vegetation intact wherever possible (except listed invasive species).*

When necessary to remove trees and other vegetation for safety reasons (sight distance, danger of falling, etcetera), remove only the vegetation that is causing the problem;

- Use selective pruning; do not cut all the shrubs back, just the branches or plants causing visibility or safety issues.

- Do not reduce shade and cover over roads and streams wherever possible.

- Maintain the riparian area on both sides of stream wherever possible.

- Do not remove live or dead woody debris within the high-water mark of streams or stream banks.

- To remove woody debris caught on bridge abutments, cut debris into smaller pieces or cable and winch the debris clear while keeping equipment outside the stream high-water mark.

If it is necessary to remove debris for human safety or to protect structures; replace debris downstream where it will not constitute a further threat.

If using chemicals for vegetation removal or weed control, contact ISDA for permitting and/or proper techniques and application rates (Appendix A).

- Follow recommended spray and application rates on packaging, and make sure spray does not get into stream.

- Do not spray on a windy day or before a rain or snow storm as the spray could wash off and cause problems downhill in streams or other vegetation not intended to be sprayed.

c) Removal of riparian vegetation (i.e., cattails) Cattails are a strong indicator of wetland conditions. If cattails or other riparian vegetation are causing drainage or site distance problems, contact the Army Corps of Engineers (Appendix A) before removing the vegetation to see if a permit is required.

Problems:

- Reduces shading of stream, affecting temperature and harming fish.

- Reduces outside inputs essential to stream life.

- Reduces streamside habitat for wildlife and fish.

- Causes debris deposition and blocking of pipes and bridge openings.

Road Maintenance Activities 25

Solutions:

- Leave all native vegetation intact wherever possible.

- Chemical removal of vegetation is regulated – contact ISDA for permit and proper technique.

- Riparian vegetation may be removed with a bucket or a shovel without requiring a permit from the Army Corps of Engineers as long as all excavated materials are placed on uplands and not in a wetland or stream channel.

8) Dust Control

“One car making one pass on one mile of a dirt or gravel road one time each day for one year creates one ton of dust”

Source: Minnesota LTAP Program presentation.

Dust is a normal part of a dirt or gravel road – moving vehicles grind the road fines into dust, which then becomes airborne. It is important to keep these fines on the road, as fines are necessary to bind the road aggregates in place and keep them there. If you are losing dust, you are losing your road.

Dust is also considered a nuisance; in fact, some parts of Idaho (referred to as non-attainment areas) are regulated for the amount of dust and particulates in the air. Dust can have a variety of negative effects on people; causing dust-induced respiratory problems and other related health problems. Dust also impacts dust-sensitive vegetation such as orchards and other crops.

Dust suppression is a necessary part of dirt and gravel road maintenance.

Left uncontrolled, dust increases air and water pollution and increases road maintenance costs. Controlling dust leaving the road reduces the necessity of blading, regrading and regravelling and reduces the amount of sediments entering waterbodies, which can affect plants, fish and other aquatic life as well as drinking water sources.

Dust control is a beneficial public relations activity. Neighbors along the road receive a financial benefit in the reduction of cleaning costs for homes, clothes and vehicles. Roads without dust also provide a higher quality of life, increase property values and reduce vehicle damage, such as broken windshields, from flying aggregate.

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Property owner request programs Some states and several agencies in Idaho share the costs of applying magnesium chloride (MgCl2) or other chemical suppressants with the property owners. If the property owner requests that a dust suppressant be applied in front of their home, suggesting they share the financial responsibilities is a good solution when budgets are tight. If there are numerous requests compose a letter outlining the details and inviting property owners to participate.

Dust control solutions:

• Shading of road surface retains moisture and reduces dust. This is only recommended where safety is not sacrificed because of the shading.

• Adding gravel to road surfaces can help keep dust down in certain soil types.

• Liquid/chemical dust suppressants can be applied by mechanical means. Examples of suppressants include; water, Sodium Chloride (salt), Calcium Chloride, Magnesium Chloride, brines (natural, semi-processed), lignin derivatives.

- Apply dust suppressants at a rate that will not run off the roads, this will vary with soil conditions – follow manufacturers ̓specified rates and all federal, state, and local regulations governing their use. If a heavier coat is desired, apply a partial cover one day and repeat the next day.

- Make sure to use a treatment that is appropriate for the local fisheries. DEQ and IDFG can provide that information (Appendix A). Asphalt emulsions and cutbacks (oils), resins can affect fish habitat and water quality or adjacent sensitive areas (crops, or other sensitive vegetation).

- Chemical products must be stored, handled, and disposed of in accordance with all applicable regulations.

- Take care when applying suppressants, assuring spray is on road surface only.

- Stop or reduce spray over bridges to prevent suppressants/ chemicals from getting into the water body below.

- Do not apply when the weather forecast calls for precipitation, as the applied chemicals will wash off.

Road Maintenance Activities 27

9) Winter Maintenance The main goal of winter maintenance is the removal of snow, ice and slush from the roadway to provide a safe driving surface; however, protection of the surrounding environment and water resources is also important.

a) Snow and Ice Removal Removal of snow, ice, and slush from roadways, ramps, interchanges, and shoulders by snow plow, grader, or snow blower.

Minimization, Avoidance, and BMPs:

1. Reduce plowing speeds in sensitive areas, such as near streams with

ESA-listed fish.

2. Adjust blower chute to minimize blowing into sensitive areas, where appropriate and if traffic allows.

3. On dirt and gravel roads leave a snow floor. Do not scrape to bare surface, helps keep sediments on the road.

b) Sanding and Pre-wetting Sanding: Supply abrasive material to roadway surfaces to assist with traction when winter weather conditions require additional traction.

Pre-wetting: Mixing pre-wetting agents, such as magnesium chloride, with sanding material helps the material bore into the snow and ice. This helps the material improve traction and stay on the road longer, which reduces the need for and amount of sand applied.

Minimization, Avoidance, and BMPs:

1. Reduce application rates and frequency of sand when weather and traffic conditions allow.

2. Carefully review the use of sanding material in the following areas:

- Areas with dust related air quality problems

- Areas where there is danger of siltation in streams, shallow lakes, or ponds (especially with listed species)

- Areas that have sensitive or rare plants near the road

3. Store sanding material and pre-wetting agents in a manner to minimize any contamination of surface or groundwater. Contain runoff from chemically treated stockpiles. Covered storage for sanding material is preferred.

4. Limit application to areas that need it most, such as steep inclines, bus routes, main traffic routes and shaded areas.

5. Treat sanding material with chemical per manufacturers ̓ recommendations when pre-wetting. If applying chemical to stockpiled material, prevent or capture runoff.

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6. Keep accurate application records of when, where, the quantity and type of sanding material applied. Keep application records of chemicals used and amounts used to pre-wet sand.

7. Place barriers in site specific locations to capture sanding material where appropriate and practical, along streams or areas that drain directly to waterbodies.

c) Anti-icing and Deicing Apply anti-icing and deicing chemicals to road surfaces to prevent snow and ice from bonding to the roadway or to break the bond between snow and ice and the roadway. This activity is performed solely for safety purposes.

The use of anti-icing and deicing chemical is helpful in reducing the need for sanding material, which will also reduce sanding related impacts to air quality, water quality, and aquatic habitat. Additionally, the use of anti-icing and deicing chemicals has been associated with vehicle accident reduction.

Minimization, Avoidance, and BMPs:

1. Use the lowest application rate necessary to achieve agency mission.

2. Carefully review the use of anti-icing and deicing chemicals in the following areas:

- Where receiving waters will not provide 100:1 dilution.

- Areas without a vegetation buffer between the road and waterbody

(especially shallow ponds, lakes, or wetlands).

- Areas having coarse soils overlying sensitive aquifers or percolation devices (French drains, etcetera).

3. Limit application to areas that need it most, such as steep inclines, bus routes and main traffic routes.

4. Keep accurate application records including when, where and quantity of chemical applied.

5. Routinely inspect equipment, including nozzles and storage tanks, for damage. Promptly repair or replace all damaged equipment.

6. Place barriers in site specific locations that are adjacent to sensitive areas or that drain directly to waterbodies.

7. Store chemicals in a manner that minimizes contamination of surface or groundwater. Care should be taken to prevent runoff from chemical tanks or chemically treated stockpiles. Covered storage is preferred for dry chemicals.

Road Maintenance Activities 29

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Chapter 2 – Drainage and Stream Crossings

“The faster the water, the greater the force, the greater the erosion!”

~ Minnesota LTAP Program presentation.

Protecting water quality is important for the aquatic and other species within the ecosystems but also for human consumption purposes. Excessive runoff and sedimentation can cause increased filtering costs for drinking water, interfere with irrigation systems and increase the potential for flood events. As seen in the Hydrologic Cycle diagram below (Figure 2.1), our drinking water and fresh waterbodies go through many processes with various opportunities to absorb pollutants, such as sediments, along the way.

When a severe storm, road or other land-altering procedure changes the land surface and interrupts the flow, loose sediments increase greatly while decreasing the water quality for all those who depend on it.

Figure 2.1 The Hydrologic Cycle

Figure 2.1 depicts several ways in which water passes through the system. Water passing over a road picking up sediments affects several other areas of the interconnected Hydrologic Cycle. Designed by:

Niklas Aleksich.

“By volume, sediment is the greatest water pollutant.”

~ Pidwirny 2001.

Proper drainage of roads, ditches and stream crossings should be a priority.

If a road is not draining properly, it can cause extra maintenance work and possibly the loss of a section of road; not to mention the effects it can have on water quality and the aquatic species dependent upon resources in the area.

Drainage and Stream Crossings 31

Road drainage requirements will vary based on the location and road materials, but is an essential component to all roadway systems. It is important not to modify existing or natural drainage patterns unless specifically directed to do so by the plans or approved by the local permitting authority.

Routine checks and preventative maintenance of drainage structures that identify problems when they are small could save time and money in the future. A properly functioning drainage system reduces travel hazards and slows down road deterioration. Check drainage systems often--before a forecasted storm and after a large storm, as well as before and after winter precipitation.

In Idaho, several fish species referred to as anadromous fish migrate up our rivers from the ocean to breed in the fresh water locations where they hatched, generally in small tributary streams. It is very important to confine work in or near streams to times when these fish are the least impacted.

It is also of great importance to provide passage at all road crossings for both juvenile and adult anadromous fish (such as salmon and steelhead), as well as resident fish species and other aquatic species such as amphibians (frogs and turtles). For appropriate in-stream work times, consult Appendix C or contact the local Idaho Fish and Game regional biologist or Tribal Fisheries department (Appendix A) who can give actual time windows for each area and help design the project in a way that is safe for fish.

Fish needs

- Suitable food

- Hiding places from predators

- Quiet-water resting places

- Spawning sites

- Clean water with oxygen

- Passage at road crossings

Source: LTAP Graphics Collection.

Determine the need for a permit for maintenance work in drainage systems – Contact the regional Army Corps of Engineers office and IDWR offices (Appendix A) with plenty of advanced notice in case a permit is required. The permitting process can take 60 to 90 days or more. Permits are generally only needed when installing a new culvert or increasing the footprint of an existing culvert.

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1) Bridges Bridges are critical structures that allow the natural flow of water under the road so that it can continue on its natural course. Bridges must be cleaned and inspected regularly; bridges should be functioning properly for both stream and vehicle passage. Regular cleaning and inspection and inlet and outlet protection (Figure 2.2) can postpone the eventual replacement of the structure.

Figure 2.2 Bridge inlet protection

This protection helps reduce the force of waters on the bank, keeping the bridge footings in place. Similar protection should also be placed at the outlet of a bridge structure. Source: Low- Volume Roads Engineering Best Management Practices Guide.

Maintenance All bridge maintenance work should be done in a way that sediments, paint chips and other hazardous materials do not enter the waterbody below.

Place a cloth or net under the bridge, but above the water surface, to catch falling debris.

- Clean the bridge deck.

- Clear vegetation and debris from in-stream supports to prevent foundation scour (remove only the debris and vegetation that is or may cause problems).

- To remove woody debris caught on bridge abutments, cut debris into smaller pieces or cable and winch the debris clear while keeping equipment outside the stream highwater mark.

If it is necessary to remove debris for human safety or to protect structures; replace debris downstream where it will not constitute a further threat.

- Replace object markers and signs as necessary.

- Repair upstream and downstream bridge approaches are protected with wing walls, rip rap, gabions, vegetation and other necessary slope protection (See Chapter 1, Section 3, page 18).

- Replace any missing nuts and bolts.

Drainage and Stream Crossings 33

For bridge work that is considered to be “maintenance” rather than construction, see Army Corps Nationwide Permit #3 in Appendix B, page 90.

Figure 2.3 Bridge options at stream crossings

Use drainage structures that conform to the natural stream channel and that are as wide as the active stream channel (at bankfull width) or meet 100-year flood standards. Source: Low- Volume Roads Engineering Best Management Practices Guide.

If a bridge needs replaced or is to be built in place of a culvert, consider the recommendations and advantages below.

Bridge replacement

- Design bridges so that water drains from the road before the bridge, but not into the stream.

- Keep bridges high; slope roads to low points away from bridges, draining ditches through vegetative filter strips.

- A bridge should span the entire natural stream channel with no restrictions to natural flows - design for 100-year flood capacity.

- Ensure upstream and downstream bridge approaches are protected with wing walls, rip rap, gabions, vegetation and other necessary slope protection (See Chapter 1, Section 3, page 18).

Advantages to building better bridges:

- Longer bridge life

- Drains bridge deck more adequately

- Drains water away from bridge

- Provides fish passage

- Less maintenance

- Less material accumulating on bridge

- Less chance of flow blockage under bridge

- No gravel bars to remove

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2) Culverts The Federal Emergency Management Agency (FEMA) defines a culvert as a prefabricated structure carrying a pathway or roadway over a depression or obstacle. Unlike a bridge, a culvert generally has a concrete or metal bottom.

Culverts require frequent maintenance to…