County of San Mateo

COUNTY OF SAN MATEO

ENDANGERED SPECIES AND WATERSHED PROTECTION PROGRAM

VOLUME 1

MAINTENANCE STANDARDS

Developed by:

County of San Mateo Department of Public Works

February 20, 2001 (Updated February 21, 2007) TABLE OF CONTENTS

Section Page

1 Introduction 1

2 Definitions 2

3 Program Review 5

4 How to Use This Manual 6

5 Discretion 7

6 Maintenance Zones 8

7 Prevention and Conservation 9 Minimization and Avoidance Permits and Reporting

8 Maintenance Activities 11

Winter Activities

8.1 Bank Stabilization 12 8.2 Slide Debris 15 8.3 Berms 17 8.4 Large Woody Debris Management/Removal 19 8.5 Road Closures 21 8.6 Snow and Ice Control 23

Routine Maintenance

8.7 Paved Road Surfaces 25 8.8 Unpaved Road Surfaces 28 8.9 Trails 30 8.10 Street Surface Cleaning 32 8.11 Shoulders and Turnouts 34

8.12 Bridges 36

Drainage Systems

8.13 Cleaning Storm Drainage Facilities 38 8.14 Culvert Installation, Repair & Replacement 40

i TABLE OF CONTENTS (continued) 8.15 Stream Crossings 43 8.16 Ditches and Swales 46 8.17 Watercourses and Streams 49 8.18 Flood Control Facilities 51

Slopes

8.19 Erosion Control 53 8.20 Slope Stabilization 55

8.21 Vegetation Management 57

8.22 Concrete 66

8.23 Sewers 69

8.24 Water Systems 71

8.25 Recycling and Disposal 73

8.26 Stormwater Pollution Prevention For 76 Maintenance Activities

9 Conservation Outcomes 9.1 Introduction 9.2 Erosion and Sedimentation Processes and Controls 80 9.3 Water Quality, Velocity and Erosive Forces 81 9.4 Air Quality 83 9.5 Habitat Protection 84 9.6 Soil Conservation 85 9.7 Vegetation Preservation/Enhancement 86 9.8 Recycling 87 9.9 Safety 88

10 Best Management Practices (BMPs)

10.1 Asphalt Berm 91 10.2 Brush Layering 92 10.3 Brush Packing 95 10.4 Clean Water Bypass 98 10.5 Cofferdam 99 10.6 Coir Fabric/Netting 100 10.7 Concrete Washout 103 10.8 Containment 104 10.9 Curb Inlet Sediment Barrier 105 10.10 Diversion Berm 107

ii TABLE OF CONTENTS (continued)

10.11 Energy Dissipater/Flume 108 10.12 Equipment Maintenance and Fueling 112 10.13 Erosion Control Blankets & Mats 113 10.14 Hand Seeding 117 10.15 Hydroseeding 119 10.16 Large Woody Debris 121 10.17 Live Pole Drain 122 10.18 Live Staking 124 10.19 Mulching 127 10.20 Rip Rap 128 10.21 Rock Slope Protection 131 10.22 Rolling Dip 132 10.23 Sand Bags/Rock Socks 135 10.24 Silt Fence 137 10.25 Stormwater Separation Systems 139 10.26 Straw Log, Straw Roll, Coir Log 140. 10.27 Streambank Stabilization 143 10.28 Surface Roughening 145 10.29 Timing of Work 148 10.30 Traffic Control 149 10.31 Vegetative Buffer 150 10.32 Vegetable-based Equipment Oil 151 10.33 Wattle/Fascine 152

Appendices

Appendix A Coastal Zone Map Appendix B Water Resources Maps Appendix C Interim DPW Debris Storage Locations Appendix D Endangered Species Information Appendix E Maintenance Notification Form (Form RM-E01) Appendix F Training and Reporting Appendix G San Mateo County Sewer Spill Response Plan Appendix H Revisions & Additions 8.14a Ditch Relief Culvert Replacement for Work Areas outside of Sensitive Habitats 8.14b Ditch Relief Culvert Replacement for Work Areas within Sensitive Habitats 8.15 On-Stream Culvert or Arch Replacement 8.27 In-Stream Structures 8.28 Miscellaneous Drainage Facility Installation, Repair & Replacement Headwall Detail (3 pages) Culvert Outlet Detail Flume/Downspout Detail Flume/Downspout Staking Detail Flume/Downspout Connection Detail

iii INTRODUCTION

The County of San Mateo Department of Public Works has developed these procedures to minimize impacts to water quality and fish and wildlife habitat throughout the unincorporated area of the County. These procedures supersede the draft Performance Standards for Rural Road Maintenance submitted to the Regional Water Quality Control Board in compliance with the County-wide National Pollutant Discharge Elimination System (NPDES) permit dated July 1999. These procedures are intended to meet both the NPDES permit requirement, and the Endangered Species Act Section 4(d) Rule for Steelhead and Salmon (September 8, 2000).

The February 2001 version of this manual contains standards, Best Management Practices (BMPs) and Conservation Outcomes for Road and Parks Maintenance Division activities expected to take place during the winter. Those activities, which include Large Woody Debris Management/Removal, Streambank Stabilization, and road-related erosion control, are the primary operational aspects of the NPDES permit program requirement.

This manual will be expanded to include standards, BMPs and Conservation Outcomes for all activities routinely undertaken by the Department of Public Works Road Maintenance and Parks Department Maintenance Divisions (including approved County-wide Stormwater Pollution Prevention Program [STOPPP] standards). Future volumes will address engineering design, construction management and inspection, and facility maintenance.

The final document will be made available to other agencies seeking to adopt similar programs.

1.0 DEFINITIONS

Berm An elevated area constructed of asphalt materials, base rock, soils, sandbags or other materials to divert runoff. Typically located along roadway shoulders.

Bioengineering Refers to the practice of vegetative engineering. The biologic parts of plants are used to arrest and prevent slope failures and erosion.

Biotechnical Methods Refers to a "mixed construction" approach that combines both vegetative and structural inert materials. Vegetation - living and/or dead - is planted, inserted, driven, buried or placed on the ground surface in ways favorable for the mitigation or prevention of erosion, to protect structural components, and to provide favorable site conditions for the establishment of a permanent vegetative cover.

Brush Vegetative material smaller in length/diameter than large woody debris. May consist of cuttings of native vegetation intended for use in slope stabilization BMPs such as brushlayering, brushpacking, willow wattles, etc.

Cut and Plug The practice of cutting woody debris in streams into small pieces and/or short lengths that may become lodged in downstream obstructions (culverts, log jams, etc.).

Coastal Zone The area west of the Coastal Zone Boundary as shown on the Coastal Zone map (Appendix A). The area is subject to special regulations under the Local Coastal Program.

Emergency An emergency consists of circumstances creating a substantial risk of loss, damage, interruption of essential services, or threat to public health or safety that could not have been reasonably foreseen. “Emergency” includes any man-made or natural event or circumstances causing or threatening loss of life, injury to person or property, including but not limited to fire, explosion, flood, severe weather, earthquake, volcanic activity, spills or releases of oil or hazardous material, contamination, actual or imminent loss of transportation facilities, civil disturbance, riot, sabotage and war.

The distinction must be made as to when the emergency is over and cleanup begins. An emergency ends when threats of loss of life or injury are mitigated and pre- emergency service is restored. Examples of emergency operations include, but are not limited to, modification of large woody debris/log jams in streams, streambank/slope stabilization, flood response and emergency road opening measures.

Habitat An area used by a species for migration, breeding, spawning, foraging, shelter, etc. May refer to generic types of habitat, such as riparian (near water bodies), upland (above riparian habitat), etc.

Large Woody Debris Large pieces of woody material 6 inches and larger in diameter and at least 10 feet long. Also includes rootwads and stumps. Typically refers to woody debris in water bodies. Large woody debris may be used to reduce water velocity and erosive forces, and to provide habitat for fish.

2.0 DEFINITIONS (continued)

Minimization and Avoidance Measures undertaken to minimize or avoid damage to any endangered species or its habitat, water quality and vegetation.

Mitigation Mitigation typically refers to efforts to restore areas damaged by construction or maintenance activities, or to replacing habitat values lost as a result of those activities whether at the same location or off-site. Mitigation work may be required by resource agencies when issuing permits.

Natural Resource A naturally occurring element of the San Mateo County environment. Includes water, air, vegetation, fish, wildlife, and soils.

Riprap Solid rock or boulder that generally ranges in size from 1' to 5' at its widest dimension. Riprap typically refers to an assemblage of rocks, versus a single boulder, and is often used in embankment repairs and slope stabilization.

Resource Agency A local, state or federal agency or department responsible for preservation of natural resources and/or regulation of activities affecting natural resources.

Revegetation The placement, planting and/or fostering of growth of beneficial plant species.

Sensitive Area/Habitat Sensitive areas and habitats are those areas identified as critical to the survival of threatened or endangered species and those areas where disturbances may negatively impact downstream or down-slope areas or habitats. The Local Coastal Program defines sensitive areas in the Coastal Zone as including all areas within 100’ of any water body.

Sidecast Material placed on or within the bank(s) of any water body; the practice of placing material on or within the bank(s) of any water body.

Slide A slope failure...

Slipout A shallow slope failure, typically involving the shoulder of a road or trail. May be caused by high groundwater, falling trees (windthrow), etc. “Slipout” generally refers to the fill (downhill) side of a facility; “slide” generally refers to slope failure on the cut slope (uphill) side.

Washout A slope or bank failure caused by the erosive forces of water. Typically involves the shoulder of a road or trail. May be caused by high flows in streams, concentrated runoff, etc.

Water Body Any permanent or seasonal water source, excluding certain types of culverts and ditches and agricultural and domestic water supply conveyances. Includes streams, creeks, tributaries, lakes, ponds, wetlands, marshes, ocean, bays, any areas populated by wetland vegetation, on-stream culverts and certain ditches

2.1 Windthrow Fallen tree(s).

2.2 PROGRAM REVIEW

These procedures will be submitted for review and comments to the California Department of Fish and Game, the National Marine Fisheries Service, the United States Fish and Wildlife Service, the Army Corps of Engineers, the Regional Water Quality Control Board, and the California Coastal Commission. They will also be distributed to interested citizens and watershed groups for comments.

The final document will be submitted for approval and development of inter-agency agreements and/or general permits to the various agencies that regulate water quality and endangered species throughout San Mateo County.

We anticipate that the standards and BMPs will be reviewed internally and with resource agency input at least once annually, and will be updated as methods are improved within the context of sound scientific research.

3.0 HOW TO USE THIS MANUAL

This manual is organized to assist maintenance managers, supervisors and crews in adhering to the standards. The standards are presented in Part 8, “Maintenance Activities.” Each maintenance activity is presented in the following manner:

DEFINITION

Brief definition of the activity. Note that one project or work performed at one site may incorporate several different activities and the applicable standards.

PURPOSE

General description of the purpose for performing the activity.

BMP OUTCOMES

Expected outcome of utilizing one or more of the listed BMPs for the activity.

CONSERVATION OUTCOMES

Resulting conservation of natural and man-made resources achieved by performing the maintenance activity (provided the standard is followed and BMPs are employed).

STANDARD

The manner in which the activity is to be performed, employing the professional judgment of managers and supervisors responsible for the work.

A list of Best Management Practices appropriate to the activity. One or more BMPs will be required in order to fully meet the standard. BMP selection will be made based on site conditions, weather and the availability of materials. BMP descriptions and detail drawings are included in Part 10 of this manual.

As this manual is used, it is anticipated that standards and BMPs will be revised to be more successful. Records of successes, failures and adaptations reported will be used to improve upon the manual and incorporate maintenance crew feedback.

4.0 DISCRETION

The standards in this manual do not include phrases such as “where feasible,” “where appropriate,” or “where practicable” as compliance with the Clean Water Act (NPDES permit) and Endangered Species Act (4(d) rule) is not discretionary. It is anticipated that road and park maintenance managers, supervisors and equipment operators will exercise professional judgment in applying these standards. If adherence to these standards is impossible in some situation, whether due to equipment, weather, safety considerations, etc., managers and supervisors will be responsible for documenting the situation and the impact minimization or avoidance measures taken, and for reporting the actions at the first opportunity.

Refer to Part 7, “Permits and Reporting,” for forms and reporting procedures.

5.0 MAINTENANCE ZONES

The County of San Mateo is generally divided by the Santa Cruz Mountains into a “Bay Side” (east of the mountain ridges and bordering San Francisco Bay) and a “Coast Side” (west of the mountain ridges and bordering the Pacific Ocean). The Coast Side is divided by the Coastal Zone Boundary (shown on the map in Appendix A), within which provisions of the Local Coastal Program apply. The unincorporated (County maintained) area is further divided into Public Works maintenance districts.

Appendix B is a map of the water resources of San Mateo County, and shows the approximate watershed boundaries for the streams and lakes. Users of this manual should be aware that those watersheds are tributaries to the San Francisco Bay and Pacific Ocean, and that maintenance activities in the watersheds have the potential to affect water quality and endangered species far beyond the limits of their work.

The U.S. Fish and Wildlife Service has designated over 90% of San Mateo County as critical habitat for the endangered California Red-legged Frog. Critical habitat has also been designated for other species, including the Bay Checkerspot Butterfly. Streams that are currently, were historically, or have the potential in the future to be habitat for coho salmon and steelhead trout are considered sensitive areas. Information about various endangered species indigenous to San Mateo County is included in Appendix D.

The standards and BMPs in this manual apply to all of the unincorporated area of San Mateo County. BMP selection may vary depending on the sensitivity of a particular area such as aquatic resources or critical habitat for endangered species. Permit requirements may also vary depending on the zone where an activity is located.

6.0 PREVENTION & CONSERVATION

Maintenance managers and supervisors are encouraged to undertake prevention and conservation measures to avoid emergencies and impacts to endangered species habitats, water resources and other sensitive areas. Such measures may include the planned installation of rolling dips; revegetation and other erosion control measures; designating and preparing storage areas for slide debris; monitoring log jams and other obstructions to stream flows adjacent to public facilities; installing trash racks and other culvert inlet improvements; installing energy dissipaters and other culvert outlet improvements; and/or improvements to drainage facilities to avoid concentrated runoff.

Minimization and Avoidance Measures

Minimization and avoidance measures refers to measures undertaken by Maintenance Division managers, supervisors and crews to minimize or avoid damage to any endangered species or its habitat, water quality and vegetation. Such measures include, but are not limited to: avoiding the use of heavy equipment within the banks of a stream or lake; using of natural materials (such as logs or stumps) in place of hard armoring with rip rap or concrete; scheduling work during the dry season to avoid polluted runoff; performing hand seeding or hydroseeding just prior to the first rains, etc.

Managers and supervisors shall document and report minimization and avoidance measures employed during emergency work for inclusion in Departmental reports and after-the-fact permits. Report form RM-E01 shall be used for this purpose.

Permits and Reporting

Permits or written exemptions are required for work involving any of the following:

1. Discharge or placement of any structure or fill below the ordinary high water line of any body of water (including rip rap, soil, concrete or asphalt, and woody material) 2. Dredging, removal or modification of any structure, fill, sediment, large woody debris or vegetation from below the ordinary high water line of any body of water 3. Any work that potentially alters the habitat of any endangered species (including streams, tributaries, lakes, ponds, certain ditches, beaches, wetlands, marshes, banks and riparian areas, and upland areas) 4. Any work in the Coastal Zone involving excavation, fill, or vegetation removal (including culvert replacements and headwall construction)

Permits or written exemptions shall be obtained prior to performing planned work such as culvert replacements, slide repairs, bank stabilization, etc. Maintenance supervisors shall keep in their possession copies of permits for work being performed under their supervision.

7.0 PREVENTION & CONSERVATION (continued)

Emergency conditions may require that work be performed prior to obtaining written permits or exemptions. Maintenance managers and/or supervisors shall complete report form RM-E01 for emergency work involving any of the elements described in 1 through 4 above. Forms shall be forwarded to the Maintenance Division Manager at the earliest opportunity, and not more than three (3) working days after completion of the work.

Form RM-E01 is included as Appendix E in this manual.

The Memorandum of Understanding (MOU) between the Department of Public Works and the California Department of Fish and Game dated August 1995 is no longer in effect and is not to be relied upon as authorization to perform any routine or emergency maintenance, or any construction of new or replacement facilities. A revision to the MOU is under negotiation.

7.1 MAINTENANCE ACTIVITIES

Bank Stabilization (February 2001) Slide Debris (February 2001) Berms (February 2001) Large Woody Debris Management/Removal (February 2001)

8.0 MAINTENANCE ACTIVITY: BANK STABILIZATION

DEFINITION

Bank stabilization activities are undertaken to repair slides, slipouts and washouts adjacent to water bodies such as creeks, streams, lakes, ponds and certain ditches. Bank stabilization activities may include removal of slide debris from the bank; backfilling or stabilizing the bank; reestablishing damaged roadway features; repairing and cleaning drainage system; and applying erosion controls.

PURPOSE

Bank stabilization activities are done to protect the public, to repair the roadway system, and to prevent further damage to the roadway, private property and/or the environment. Bank stabilization may be undertaken as either an emergency response to mitigate ongoing or imminent damage, or as a planned restoration project.

BMP OUTCOMES

 Stabilize damaged area within the right of way to reduce transportation, structural and environmental impacts  Protect water quality by reducing erosion/sedimentation  Repair roadways, drainage, storm water and other right of way structures  Prevent potential water pollution from equipment operations

 Prevent catastrophic road failure  Protect water quality by reducing erosion/sedimentation  Encourage revegetation to stabilize slope and protect sensitive aquatic habitat  Maintain or restore the storage, delivery and routing of surface runoff and ground water  Contribute to restoration of aquatic habitat by reducing erosion / sedimentation, maintaining or restoring stream flow volumes and velocities, and revegetating disturbed areas

STANDARD

Permits are required for all bank stabilization activities. Permits shall be obtained prior to performing planned bank stabilization work. When bank stabilization work is performed as an emergency response, the activity shall be reported immediately (Form RM-E01 protocol) and any “after the fact” permits shall be obtained and mitigation requirements undertaken.

8.1 Maintenance Activity: BANK STABILIZATION (continued)

Areas adjacent to water bodies that wash or slip out, reducing the width of the traveled way, shall be evaluated for:

1. Temporary one-way traffic controls 2. Temporary closure of the road if adequate alternate route(s) exist 3. Rerouting road into cut slope (if impacts are minimal, within right of way or with written approval from property owner) 4. Emergency stabilization using large wood materials (root wads, log cribbing, etc.) 5. Placement of asphalt concrete or cutback berms to divert runoff away from the damaged area

No slide debris or other spoils shall be sidecast or used to construct, repair, augment or replace berms within 150 feet of any water body. Refer to the section entitled “Slide Control/Slide Debris,” for temporary storage of material.

Rip rap shall only be used on stream banks for emergency stabilization on roads that have no alternate access (i.e. Canyon Road to the Butano Colony and Gazos Creek Road between Cloverdale Road and the Mountain Camp), where one or more of the following apply:

1. Rip rap previously existed, and is to be replaced in the same quantity and location and is immediately reported 2. Rip rap is to be placed only below the ordinary high water line to halt scour at the toe of a slope or bank supporting a public road, and is immediately reported 3. Large wood materials (root wads, logs, etc.) are not available

Rip rap may be used to protect bridge support structures (abutments, embankments, etc.) that are actively being undermined and are at imminent risk of failure.

Wherever possible, key trenches shall be dug prior to placing rip rap.

Rip rap may be used for non-emergency stabilization only after all applicable permits have been obtained. Proposals for non-emergency rip rap use shall include mitigation and avoidance measures such as incorporating large woody debris, revegetation, etc.

 Asphalt Berm  Containment  Filter Fabric  Hand Seeding  Large Woody Debris  Live Staking  Mulching  Rolling Dip/Water Bar  Sandbags  Streambank Stabilization

8.2 MAINTENANCE ACTIVITY: SLIDE DEBRIS

DEFINITION

Slides and slipouts are caused by the impact of heavy rainfall, concentrated runoff onto unstable slopes, and high groundwater conditions. Slides and slipouts may occur on the slope above or below roadways, private property or sensitive areas. Slide debris management activities may include: removal of slide debris/soils from right of way; hauling, storage and stabilization of debris; repairing and cleaning drainage systems.

Slides and slipouts occurring adjacent to water bodies are addressed under “Streambank Stabilization.”

PURPOSE

This emergency response activity is done to protect the public, and to prevent further damage to the roadway, private property and/or the environment.

BMP OUTCOMES

 Control sediment and debris  Stabilize damaged area within the right of way to reduce transportation, structural and environmental impacts  Protect water quality by reducing erosion/sedimentation

 Provide safe transportation corridors  Maintain or restore the storage, delivery and routing of surface runoff  Contribute to restoration of sensitive habitats by reducing erosion / sedimentation and revegetating disturbed areas

STANDARD

Slide debris shall be removed to the nearest suitable area for temporary storage, and shall be enclosed or contained after the emergency to prevent erosion. In no event shall slide debris removed by County Road crews be allowed to erode into any water body. Slide debris shall be removed to the nearest permanent, stable storage or recycling location at the earliest opportunity, or may be used as backfill in permanent repair projects.

Slide debris shall not be sidecast and shall not be used to construct, repair, augment or replace berms within 150 feet of any water body.

8.3 Maintenance Activity: SLIDE DEBRIS (continued)

Large woody debris removed with slide debris on the coast side shall be transported to the designated area at the quarry or other suitable locations for use in bank stabilization activities.

Wherever possible, brush and garbage shall be sorted and stored separately from soils.

 Diversion Berm  Silt Fence  Straw Bale Barrier  Straw Log/Straw Roll

8.4 MAINTENANCE ACTIVITY: BERMS

DEFINITION

Berms are elevated areas constructed of asphalt materials, base rock, soils, sandbags or other materials along roadway shoulders.

PURPOSE

Berms are created and maintained to control and direct surface runoff away from unstable slopes. Berms may also provide a measure of traffic safety on narrow roads or where sufficient shoulder width is lacking. Berm areas may be used for temporary storage of slide debris where the berm is more than 150’ horizontally from any water body and failure of the berm or sidecast over the berm will not contribute to sedimentation into a sensitive area.

BMP OUTCOMES

 Control runoff  Control erosion and sedimentation  Stabilize damaged area within the right of way to reduce transportation, structural and environmental impacts  Provide a vegetated buffer to trap sediment and debris

 Protect unstable slopes by controlling and directing surface runoff  Protect water quality by reducing erosion/sedimentation  Contribute to restoration of sensitive habitats by reducing erosion / sedimentation and revegetating disturbed areas  Preserve and/or enhance visual resources  Preserve and/or enhance traffic safety by reducing channelized runoff

STANDARD

Existing earthen berms within 150 feet of any water body shall not be constructed, repaired, augmented or replaced in kind. Refer to the section entitled “Slide Debris,” for temporary storage of material.

Where berm or bank failures have occurred and runoff is contributing to damage, earthen berms shall be replaced with asphalt or cutback berms, sandbags, flumes or other devices, and measures employed to control or divert runoff. Appropriate traffic warning devices shall be placed to warn motorists of the hazard.

8.5 Maintenance Activity: BERMS (continued)

Existing earthen berms that have not been smoothed, vegetated, treated with erosion controls or which lack sufficient runoff controls should be scheduled for upgrading. Where new runoffs are created, overside drains and/or energy dissipaters should be installed. All bare soils shall be revegetated and/or mulched.

 Asphalt Berm  Energy Dissipater/Flume  Hand Seeding  Mulching  Sand Bags

8.6 MAINTENANCE ACTIVITY: LARGE WOODY DEBRIS MANAGEMENT/REMOVAL

DEFINITION

Large woody debris is defined as logs with average diameter of 6” or greater and of length 10’ or longer, rootwads and stumps. Large woody debris and log jams provide good quality in-stream habitat for fish, frogs and other aquatic species, and may provide beneficial stream grade control.

PURPOSE

Large woody debris management (modification and/or removal) is undertaken only if the integrity of roads, bridges, or other public facilities is threatened or are currently being damaged. Large woody debris modification and/or removal may be undertaken as either an emergency response to mitigate ongoing or imminent damage, or as a planned and permitted restoration project.

BMP OUTCOMES

 Avoid contributing to downstream jams and/or flooding  Minimize negative impacts to aquatic habitat  Protect water quality by reducing erosion/sedimentation  Revegetate impacted stream bank areas  Prevent potential water pollution from equipment operations

 Reduce damage to public facilities while preserving sensitive aquatic habitat  Contribute to restoration of sensitive habitats by reducing erosion / sedimentation and revegetating disturbed areas  Preserve large woody materials for use in bank stabilization or habitat restoration activities

STANDARD

Permits are required for all large woody debris management/removal activities. Permits shall be obtained prior to performing planned large woody debris management/removal work. When large woody debris management/removal work is performed as an emergency response, the activity shall be reported immediately (Form RM-E01 protocol) and any “after the fact” permits shall be obtained and mitigation requirements undertaken.

Large woody debris on County-owned property or in the public right of way shall not be removed or physically altered (sawn, repositioned, etc.) in any body of water except under the following emergency conditions:

8.7 Maintenance Activity: LARGE WOODY DEBRIS MANAGEMENT/REMOVAL (continued)

1. Material backing up flows at a bridge or culvert during a storm may be modified to halt damage or flooding.

2. Large woody debris/log jams on public property that are damaging or immediately threatening the integrity of roads, bridges, other public facilities or private developments during high flows may be modified to reduce or halt damage and direct flow toward a more desirable path.

3. Logs and debris shall only be removed from streams as a “last resort” (i.e. failure to remove them will certainly cause the loss of an essential facility).

4. Non-emergency debris maintenance will only be undertaken after the appropriate permits have been obtained.

Crews shall take precautions to ensure that modifications of log or debris jams will not cause damage downstream. “Cut and plug” practices shall be avoided.

Emergency modifications and/or removal shall be limited to materials higher than approximately 2’ above the streambed (i.e. above knee height) to preserve some instream habitat features unless the log or debris jam is immediately upstream of a culvert or bridge, or if permit conditions require otherwise.

Emergency modification and/or removal of large woody debris shall be reported on form RM-E01.

Large woody debris removed from water bodies shall either be immediately incorporated into streambank repairs or cribbing at a nearby location, or shall be transported to the Pescadero Quarry for storage. Trees, logs and/or stumps shall be left in the longest lengths/diameters practicable for removal and hauling. If logs must be cut from fallen trees, at least 12’ of trunk shall be left attached to the root ball and logs shall be left at least 20’ long.

 Containment  Hand Seeding  Large Woody Debris  Mulching  Streambank Stabilization

8.8 CONSERVATION OUTCOMES

INTRODUCTION

The Conservation Outcomes described in this section are the resulting conservation of natural and man-made resources achieved by performing the maintenance activity.

Each Maintenance Activity provides some measure of conservation, provided the standard is followed. Appropriate application of BMPs results in conservation of resources, and may ultimately conserve time and effort by preventing future damage and/or inadvertent violation of environmental regulations.

Maintenance managers and supervisors are encouraged to report their conservation efforts so that this program may be continually improved for field use and so that those efforts may be acknowledged in annual reporting to the various regulatory agencies.

The Conservation Outcomes are presented with a brief description of the benefits of the listed BMPs, some example applications and limitations on BMP use, and a list of BMP options. Descriptions of the BMPs and procedures for selecting and installing them are included in Part 10, “Best Management Practices.” 9.0

CONSERVATION OUTCOMES: EROSION AND SEDIMENTATION PROCESSES AND CONTROLS

Soil disturbance, whether by natural forces or by construction and maintenance activities, drastically accelerates the rate of erosion. Careful planning combined with proper selection and installation of erosion control measures can reduce the impact of construction and maintenance related erosion.

SOIL EROSION PROCESS

 Splash erosion results when raindrops fall on bare or sparsely vegetated soil and detach the soil particles.  Sheet erosion occurs when these soil particles are transported in a thin layer, or sheet, by flowing water.  Rills and gullies are formed by concentrated, high velocity sheet flow. More soil detaches, increasing the erosion damage.  Stream and channel erosion occurs by even higher rates of velocity and steepness of slope.  Wind erosion occurs during dry weather conditions and high winds. Size of particles being moved is related to wind velocity. Particles move by wind may cause air pollution, soil loss and/or water quality degradation.

Water quality and fish habitat are the major concerns associated with soil movement. Loss of top soils prohibit the regrowth of native vegetation and may contribute to the growth of non-native, invasive plants and weeds with little or no erosion control, bank stabilization or habitat benefits.

Erosion control BMPs combined with training, oversight and maintenance, will enable maintenance personnel to lessen the effects of soil erosion and sedimentation.

PRINCIPLES OF EROSION AND SEDIMENTATION CONTROL

Effective erosion and sedimentation control requires first that the soil surface be protected from the erosive forces of wind, rain and runoff, and second that eroded soil be captured on-site. The following conservation principles shall be integrated into a system of control measures and management techniques to control erosion and reduce off-site sediment migration.

MINIMIZE THE EXTENT AND DURATION OF EXPOSURE Schedule construction activities to minimize the exposed area and the duration of exposure. Stabilize disturbed areas as quickly as possible.

PROTECT AREAS TO BE DISTURBED FROM STORMWATER RUNOFF Use berms, diversions, pumps, and barriers to intercept runoff and divert it away from excavations and other disturbed areas. Install these measures before beginning maintenance activities. 9.1 Conservation Outcomes: PRINCIPLES AND PROCESSES OF EROSION AND SEDIMENTATION (continued)

STABILIZE DISTURBED AREAS Removing the vegetative cover and altering the soil structure by clearing the surface increase an area’s susceptibility to erosion. Apply stabilizing measures after the land is disturbed and implement temporary or permanent vegetation, mulches, or other CMPs to correspond with maintenance activities. During the winter season, November through April, no soils shall remain exposed and unworked for more than 2 days. During the summer season, May through October, no soils shall remain exposed and unworked for more than 7 days. This condition applies to all soils on site, whether at final grade or not.

MINIMIZE RUNOFF VELOCITIES Clearing existing vegetation reduces the surface roughness and infiltration rate and thereby increases runoff velocities and volumes. Use measures that break the slopes to reduce the problems associated with concentrated flow volumes and runoff velocities.

RETAIN SEDIMENT ON THE SITE Even with careful planning some erosion is unavoidable. The resulting sediment must be trapped on the site. Plan the location where sediment deposition will occur and maintain access for cleanout.

INSPECT AND MAINTAIN CONTROL MEASURES Inspection and maintenance are vital to the performance of erosion and sedimentation BMPs. Failure of a BMP may be hazardous or damaging to roadway infrastructure, habitat, people and/or property. It is essential to inspect all BMPs to ensure that they are working properly and to ensure that problems are corrected as soon as they develop.

CONSERVATION OUTCOMES: WATER QUALITY, VELOCITY AND EROSIVE FORCES

BMPs in this category reduce or diminish the water velocity, thereby dissipating its erosive forces and protecting water quality.

Application: These BMPs work well:  on stream and ditch banks  in swales  on slopes  on large disturbed areas

Limitations: These BMPs should not be used when maintenance activities are conducted in locations which could reduce actual or potential fish or frog habitat. These BMPs may be required by permit conditions.

BMP Options (include but not limited to):

 Asphalt Berm  Brush Layering  Brush Packing  Coir Fabric/Netting  Diversion Berm  Hand Seeding  Hydroseeding  Large Woody Debris  Live Pole Drain  Live Staking  Mulching  Rolling Dip  Straw Log, Straw Roll, Coir Log  Streambank Stabilization  Wattle/Fascine 9.4 CONSERVATION OUTCOMES: AIR QUALITY

BMPs in this category preserve and enhance air quality by reducing the introduction of wind-borne dust and debris.

Application: These BMPs work well:  where soil surfaces have been disturbed by construction activities, storm damage, etc.  during the dry season

Limitations: Additional Air Quality BMPs applicable for equipment operations will be included in a future edition.

 Hydroseeding  Mulching

9.5 CONSERVATION OUTCOMES: HABITAT PROTECTION

BMPs in this category provide protection to endangered species and their habitats by minimizing impacts to water quality; providing erosion control and revegetation on disturbed soils; preserving and promoting growth of native vegetation; discouraging propagation of non-native and invasive plant species and providing large woody debris for in-stream fish habitat.

Application: These BMPs work well:  near streams and other bodies of water  where native plant growth is desirable

Limitations: These BMPs may be difficult to apply during emergency operations and/or wet weather conditions. They will be often be required by permit conditions.

 Asphalt Berm  Brush Layering  Brush Packing  Coir Fabric  Diversion Berm  Hand Seeding  Hydroseeding  Large Woody Debris  Live Pole Drain  Live Staking  Mulching  Rolling Dip  Streambank Stabilization  Wattle/Fascine

9.6 CONSERVATION OUTCOMES: SOIL CONSERVATION

BMPs in this category preserve topsoil resources and enhance water quality and in- stream habitat by reducing sedimentation.

Application: These BMPs work well:  where soil surfaces have been disturbed by construction activities, storm damage, etc.  where native plants are desirable

Limitations: Soil conservation BMPs may need to be supplemented with sediment retaining structures or devices (temporary sediment trap, straw logs, etc.) during wet weather conditions.

 Asphalt Berm  Brush Layering  Brush Packing  Coir Fabric  Diversion Berm  Hand Seeding  Hydroseeding  Live Pole Drain  Live Staking  Mulching  Rolling Dip  Streambank Stabilization  Wattle/Fascine

9.7 CONSERVATION OUTCOMES: VEGETATION MANAGEMENT

BMPs in this category preserve native vegetation, thereby enhancing habitat (shade, refuge and food sources), discouraging the growth of non-native and invasive species, reducing soil disturbances and surface erosion, and reducing the risk of wildfire.

Application: These BMPs work well:  where soil surfaces have been disturbed by construction activities, storm damage, etc.  where specific Integrated Vegetation Management plans have not been developed

Limitations: Preserving existing vegetation may be impracticable in areas of high fire danger or where mowing or spraying is conducted for traffic safety.

 Hand Seeding  Hydroseeding  Mulching

9.8 CONSERVATION OUTCOMES: RECYCLING

BMPs for use of recycled construction materials and for recycling of construction and/or demolition debris will be added in a future edition.

A conservation outcome of applying the standards and BMPs for Slide Debris and Streambank Stabilization is the reuse of native materials (soils and large woody debris). Mulching exposed soils with native leaf litter and duff provides a reuse for those materials, as well as supplying native plant seeds to disturbed areas.

 Brush Layering  Brush Packing  Large Woody Debris  Mulching  Streambank Stabilization

9.9 CONSERVATION OUTCOMES: SAFETY

The safety of the maintenance workers and motoring public is of paramount importance. The need to provide safe transportation corridors in areas subject to a variety of natural disasters, while simultaneously protecting endangered species, presents a unique challenge to maintenance operations.

Maintenance workers, supervisors and managers use their professional judgment in determining whether an emergency exists and how to apply the standards and BMPs during an emergency. The preservation of life safety is the outcome of many of these field decisions.

9.10 BMPs BEST MANAGEMENT PRACTICES

BMPs: Asphalt Berm Brush Layering Brush Packing Cofferdam Coir Fabric/Netting Curb Inlet Sediment Barrier Diversion Berm Energy Dissipater/Flume Erosion Control Blankets & Mats Hand Seeding Hydroseeding Large Woody Debris Live Pole Drain Live Staking Mulching Rip Rap Rolling Dip Sand Bags Silt Fence Straw Log, Straw Roll, Coir Log Streambank Stabilization Surface Roughening Timing of Work Vegetative Buffer Wattle/Fascine

10.0 BMP: ASPHALT BERM

DESCRIPTION

An asphalt berm is a ridge of asphalt concrete or “cutback” constructed at the top of a disturbed slope. The purpose of the BMP is direct stormwater runoff away from an unstable slope.

APPLICATIONS

This BMP may be used wherever stormwater runoff must be diverted away from a disturbed slope and toward a sediment containment facility or stable runoff.

LIMITATIONS

This BMP should not be used:

 to concentrate runoff onto unstable, eroded areas.

CONSTRUCTION GUIDELINES

 Construct asphalt berm to the minimum height and width needed to divert runoff without adding unnecessary weight.  Asphalt berms may be striped or marked for traffic safety.  Asphalt berms may be used to anchor temporary plastic sheeting.

BMP MAINTENANCE

 Periodic inspection should be conducted, and berms repaired as necessary.

BMP REMOVAL

 Asphalt berm removal may not be necessary, or may be conducted during permanent slope or streambank repair activities.  Recycle or reuse asphalt berm material if applicable.  Dispose of plastic sheeting if applicable.

10.1 BMP: BRUSHLAYERING

DESCRIPTION

Brushlayering is a technique used in stabilizing shallow slope failures or rebuilding slopes which incorporates willows and other types of branches with soil backfill. Live brush layers act as horizontal drains, improve slope stability by providing tensile strength and natural revegetation. Brushlayering may include the use of geogrids or fabric soil wraps and rip rap or other structural toe support.

APPLICATIONS

Brushlayering involves relatively simple construction. Among the ground stabilizing techniques, the brushlayer has an immediate impact, its protective and stabilizing effect extending into lower soil horizons. At extreme sites where erosion, deposition, and rockfall are particular hazards, brush layers and the pioneer vegetation that develops with them are gradually eliminating these problems. Fast establishment of a stable soil- root complex is possible. Relatively short and spreading branches of the scrub willows growing in mountainous regions can be used. Simultaneous brushlayering construction during fill operations is possible. It is one of the best techniques for revegetating and stabilizing streambanks and slopes. Living and non-living brush layers along streambanks also provide valuable fish habitat.

LIMITATIONS

 Not suitable for the stabilization of deep, organic topsoil layers.  Live materials should be harvested and constructed during the dormancy stage of plant growth.  Permits may be required for installation along streambanks.

Choose a technique such as key trenching, rock toe, retaining wall, root wads, live siltation, coir logs, or buried toe rock to secure the toe of the slope. Begin layering at the bottom of the slope. Along a stream, the first brush layer typically occurs at the mean high water (MHW) level, often identified by the line of growing vegetation. A brush layer may be installed below MHW to create fish habitat and temporary plant cover.

Excavate a bench 2 to 3 feet deep so that it angles slightly down and into the slope. Twenty to 25 branches are placed on the bench, slightly criss-crossed. The basal ends are placed into the slope with the tips extending beyond the edge of the bench no more than ¼ the total branch length. Place 2 to 4 inches of soil on top of the branches and tamp into place.

10.2 BMP: BRUSHLAYERING (continued)

Repeat the branch, topsoil, layering sequence until the desired bank height is achieved. Fill slopes can be created at the same time a brush layer is installed.

On a cut slope and existing streambanks, each layer is excavated at the time the brush layer is installed.

BMP MAINTENANCE

 No maintenance of brushlayers should be required if materials are placed at appropriate depths.  Fill slopes should be periodically inspected and any failures corrected immediately.

MATERIALS

Materials include branches and cuttings of deciduous woody plants capable of producing adventitious roots, most appropriately willow. Live brushlayer materials can be stored in containers under shade until installation. For best results, soak willow for at least 24 hours, or up to 30 days. Willows may be bundled and soaked in a stream near the project site.

Soaking willow cuttings.

BMP REMOVAL

 Not required.

10.3 10.4 10.5 10.6 (This page left blank intentionally.)

10.7 BMP: BRUSH PACKING

DESCRIPTION

Brush packing is a biotechnical gully and slump repair technique. Cuttings or branches of rootable plant species are layered between successive lifts of soil fill to repair large rills, gullies, and small slumps on slopes.

APPLICATIONS

Since brush packing involves refilling the gully with soil between successive layers of branches, this practice is not recommended for gully repair in drainages or ephemeral stream channels. The slope and gully must have soil material available with which to fill the slumps and gullies. Brush packing should be used in conjunction with slope scaling or slope grading activities where rills, gullies, and other channelizations are removed by re-grading.

Brush packing utilizes alternating layers of live branch cuttings and soil to repair large rills, gullies, and slumps. Similar to brush layering, the brush packing technique is more appropriate for the repair of gullies on slopes, and it can be implemented with hand labor.

LIMITATIONS

 Not suitable for the stabilization of deep, organic topsoil layers.  Live materials should be harvested and constructed during the dormancy stage of plant growth.  Permits may be required for installation along streambanks.  Usually requires manual labor to fill and regrade slope.

It is imperative to treat any source of concentrated flows or other causes of gulling before performing brush packing treatments. Cut branches to a length which corresponds to the depth of the gully. Branches should extend the entire depth of the rill or gully, with tips protruding from the slope face when grading is complete. Branch cuttings shall be a mixture of younger wood and older wood, from 6-50 mm (¼-2 inches) diameter.

Fill the bottom of the rill, gully, or slump with soil, approximately 12 inches, and shape and compact the soil terrace such that it dips into the slope. Place branch cuttings, 3-8 inches thick, in a crisscross or overlapping configuration. The growing tips shall protrude 6-12 inches from the slope face, with the basal ends dipping back into the slope. It is important that the basal ends of the branches are lower than the branch tips. Live stakes may be driven through the soil-branch layers for extra stabilization.

10.8 BMP: BRUSH PACKING (continued)

Continue re-grading the slope and cover the brush layer with a 150-300 mm (6-12 inch) layer of soil. Compact to ensure good soil contact with the branch cuttings. Then continue brush packing and soil layering until the gully is filled and the slope is re- graded. The final installation should match the existing slope with the in-field section slightly higher to ensure that runoff collection and channelization does not occur.

Seed and mulch the slope. Shallow slopes, generally 3:1 or flatter, may be seeded and mulched by hand. Steeper slopes should have seed applied hydraulically and the mulch shall be anchored with tackifier or other approved methods.

BMP MAINTENANCE

 Regular inspection and maintenance should be conducted, particularly during the first year.  Failures of fill or drainage structures should be corrected immediately.

MATERIALS

Live materials needed include branches and cuttings of deciduous woody plants capable of producing adventitious roots, most appropriately willow. Straw or other mulch can be mixed with soil to help fill in the gully.

Coir netting or erosion control blanket material can be wrapped around the soil layers to protect the slope face (see Brush Layering with Soil Wrap).

Polypropylene geogrids can be incorporated into the soil layers if additional strength and durability are desired.

BMP REMOVAL

 Not required.

10.9 10.10 BMP: COFFERDAM

DESCRIPTION

A cofferdam is a temporary structure built into a waterway to enclose a construction area and reduce sediment pollution from construction work in or adjacent to water. Cofferdams may be made of rock, sand bags, wood or aqua barriers.

APPLICATIONS

This BMP may be used in construction activities such as streambank stabilization, culvert installation, bridges, piers or abutments. It may be used in combination with other methods such as clean water bypasses and/or pumps.

LIMITATIONS

 Should not be used if there is insufficient streamflow to support aquatic species.  Should not be used in deep water unless designed or reviewed by and engineer.  Should not be used to completely dam streamflows.

When used in watercourses or streams, cofferdams must be used in accordance with permit requirements. Materials for cofferdams should be selected based on ease of maintenance and complete removal following construction activities.

BMP MAINTENANCE

 During construction, inspect daily during the work week.  Schedule additional inspections during storm events.  Immediately repair any gaps, holes or scour.

BMP REMOVAL

 Remove sediment buildup.  Remove BMP. Recycle or re-use if applicable.  Revegetate areas disturbed by BMP removal if applicable.

10.11 10.12 BMP: COIR FABRIC/NETTING

DESCRIPTION

Coir fabric/netting is a geo-textile product made form coconut fibers loosely woven into a fabric usually packaged in roll form. This fabric can be used to provide a reduction in water velocity/erosive forces and/or habitat protection and topsoil stabilization.

APPLICATIONS

This BMP may be used in areas to provide stabilization/protection to the soil surface of steep slopes or stream banks. It can be used in combination with vegetation and/or seeding to reinfoce soil in high flow/high velocity waters and on slopes as steep as 1:1. It may be used as bank stabilization before vegetation efforts have occurred.

Coir fabric or netting is preferred to jute. Jute fabrics are often treated with preservatives that will discourage the growth of vegetation. Jute will also degrade much more quickly than coir.

LIMITATIONS

 In the streambed.  When short-term biodegradability is desired.

 When used near watercourses or streams, coir fabrics/nettings must be used in accordance with permit requirements.  Fabric may be laid out horizontally or vertically on slope.  Stakes or staples must be used to anchor fabric to ground.  Lay loosely on the surface so fabric makes contact with the ground (do not stretch for extra coverage).  Overlap fabric edges at least 12 inches.  The fabric should be trenched in at least 12 inches deep at the top and bottom ends of the installation to prevent undercutting.  If used in conjunction with hand seeding or hydroseeding, place seeding first and cover with fabric.  Live staking may be done after the fabric is placed by piercing the fabric.

10.13 BMP: COIR FABRIC/NETTING (continued)

BMP MAINTENANCE

 During construction, inspect daily during the work week.  Schedule additional inspections during storm events.  Make any required repairs immediately.

BMP REMOVAL

 BMP removal is not necessary. 10.14 BMP: CURB INLET SEDIMENT BARRIER

DESCRIPTION

Curb inlet sediment barriers are temporary barriers constructed from concrete block and gravel or gravel filled sandbags.

APPLICATIONS

Curb inlet sediment barriers are intended to reduce the sediment discharged into storm drains by ponding the runoff and allowing the sediment to settle out. The structures allow for overflow from high runoff events and the gravel allows the ponds to dewater rapidly. Curb inlet sediment barriers should be used where new construction, reconstruction and/or where private development is generating sediment or polluted runoff.

LIMITATIONS

 This BMP should not be used on steep sloping streets.  This BMP should be considered a “backup” used in addition to controlling potential erosion at the source.

 Place the barriers on gently sloping streets where water can pond.  The barriers must allow for overflow from a severe storm event. A spillway shall be constructed with the sandbag structures to allow overflow.  Sandbags shall be filled with 3/4 inch drain rock or 1/4 inch pea gravel.  The sandbags shall be placed in a curved row from the top of curb at least 3 feet into the street. The row should be curved at the ends, pointing uphill.  Several layers of bags should be overlapped and packed tightly.  Leave a one-sandbag gap in the top row to act as a spillway.

BMP MAINTENANCE

 Inspect and clean barrier during and after each significant storm and remove sediment from behind sandbag structure after every storm.  Any sediment and gravel shall be immediately removed from the traveled way of roads.  The removed sediment shall be placed where it cannot enter a storm drain, stream, or be transported off site.  If the gravel becomes clogged with sediment, it must be carefully removed from the inlet and either cleared or replaced.

10.15 BMP: CURB INLET SEDIMENT BARRIER (continued)

BMP REMOVAL

 BMP removal should not be necessary.

10.16 10.17 BMP: DIVERSION BERM

DESCRIPTION

A diversion berm is a temporary ridge of compacted soil or aggregate base material, sandbags or continuous bag berm constructed at the top or base of a disturbed slope. The purpose of the BMP is direct stormwater runoff away from an unstable slope.

APPLICATIONS

This BMP may be used wherever stormwater runoff must be temporarily diverted away from a disturbed slope and toward a sediment containment facility or stable runoff.

LIMITATIONS

 in fast flowing water.  as a replacement for failing roadway shoulders.  as slide debris storage within 150’ of any water body.

 Berm material should be adequately compacted to prevent failure.  Temporary seeding and mulch shall be applied to all surfaces of a soil diversion berm according to the “Timing of Work” BMP.

BMP MAINTENANCE

 Periodic inspection should be conducted, and berms repaired as necessary.

BMP REMOVAL

 Evaluate site to determine BMP is no longer needed (the area has stabilized – potential of sediment laden water exiting the area has passed).  Remove sediment buildup.  Remove BMP – recycle and/or re-use if applicable.  Revegetate area disturbed by BMP removal if applicable.

10.18 BMP: ENERGY DISSIPATER

DESCRIPTION

An energy dissipater is a structure designed to control erosion at the outlet of a channel or conduit by reducing the velocity of flow and dissipating the energy.

APPLICATIONS

This BMP is required at the outlet of any new or replacement drainage culvert. Existing culverts shall be evaluated and upgrades (energy dissipater installations) scheduled as appropriate.

The outlets of channels, conduits, and other structures are points of high erosion potential. To prevent scour and undermining, an outlet stabilization structure is needed to absorb the impact of the flow and reduce the velocity to non-erosive levels.

A riprap-lined apron is a commonly used practice for this purpose because of its relatively low cost and ease of installation. The riprap apron should be extended downstream until stable conditions are reached, even though this may exceed the length calculated for design velocity control. Down drains and flumes may also be used as energy dissipaters. Rock aprons may also be required below down drains and flumes depending on slope steepness and soil conditions.

LIMITATIONS

 This BMP shall not be used below the mean high water line of any water body unless permits have been obtained.  Consider other energy dissipaters such as concrete impact basins or paved outlet structures where site conditions warrant.  Rock/rip rap dissipaters may require containment in gabion baskets or mattresses to maintain their effectiveness.

 Berm material should be adequately compacted to prevent failure.  Temporary seeding and mulch shall be applied to all surfaces of a soil diversion berm according to the “Timing of Work” BMP.

BMP MAINTENANCE

 Inspect outlet structures after heavy rains to see if any erosion around the structures has taken place or if stones have been dislodged. Immediately make all needed repairs to prevent further damage.

10.19 BMP: ENERGY DISSIPATER (continued)

 Clean flumes as necessary.

BMP REMOVAL

BMP: EROSION CONTROL BLANKETS & MATS

DESCRIPTION

Erosin control blankets and mats are installed to protect the prepared soil surface of a steep slope.

APPLICATIONS

Erosion control blankets are used on steep slopes to temporarily stabilize and protect disturbed soil from raindrop impact and surface erosion, to increase infiltration, decrease compaction and soil crusting, and to conserve soil moisture. Erosion control blankets also protect seeds from predators, reduce desiccation and evaporation by insulating the soil and seed environment.

Some types of erosion control blankets and turf reinforcement mats are specifically designed to stabilize channelized flow areas.

LIMITATIONS

 This BMP should not be used in areas subject to scour from high flows (e.g. streambanks) unless designed by an engineer. Permits shall be obtained prior to any streambank or shoreline installation.  Blankets and mats manufactured with plastic netting shall be avoided.

 Proper site preparation is essential to ensure complete contact of the protection matting with the soil.  Grade and shape area of installation.  Remove all rocks, clods, vegetative or other obstructions so that the installed blankets, or mats will have direct contact with the soil.  Prepare seedbed by loosening 2-3 inches (50-75 mm) of topsoil above final grade.  Seed area before blanket installation for erosion control and re-vegetation. (Seeding after mat installation is often specified for turf reinforcement application.)  U-shaped wire staples, metal geotextile stake pins, or triangular wooden stakes can be used to anchor mats to the ground surface. Wire staples should be a minimum of 11 gauge. Metal stake pins should be 3/16 inch diameter steel with a 1 1/2 inch steel washer at the head of the pin. Wire staples and metal stakes should be driven flush to the soil surface. All anchors should be 6-8 inches long and have sufficient ground penetration to resist pullout. Longer anchors may be required for loose soils.

10.23 BMP: EROSION CONTROL BLANKETS & MATS (continued)

Installation on Slopes:

 Begin at the top of the slope and anchor its blanket in a 6 inch deep x 6 inch wide trench. Backfill trench and tamp earth firmly.  Unroll blanket downslope in the direction of the water flow.  The edges of adjacent parallel rolls must be overlapped 2-3 inches and be stapled every 3 feet.  When blankets must be spliced, place blankets end over end (shingle style) with 6 inch overlap. Staple through overlapped area, approximately 12 inches apart.  Lay blankets loosely and maintain direct contact with the soil - do not stretch.  Blankets shall be stapled sufficiently to anchor blanket and maintain contact with the soil. Staples shall be placed down the center and staggered with the staples placed along the edges Steep slopes, 1:1 to 2:1, require 2 staples per square yard. Moderate slopes, 2:1 to 3:1, require 1-2 staples per square yard (1 staple 3’ on center). Gentle slopes require 1 staple per square yard.

BMP MAINTENANCE

 All blankets and mats should be inspected periodically following installation.  Inspect installation after significant rainstorms to check for erosion and undermining. Any failure should be repaired immediately.  If washout or breakage occurs, re-install the material after repairing the damage to the slope or drainageway.

BMP REMOVAL

BMP: HAND SEEDING

DESCRIPTION

Hand Seeding is broadcasting grass seed on disturbed or bare soil areas by hand or a hand seeding device. This BMP is used to reduce the potential for soil to become water or air borne, reduce erosion after vegetation establishment, provide for vegetative buffers and aid in habitat protection. Seeding with appropriate seed mixes will also help discourage colonization by non-native and invasive plant species.

APPLICATIONS

Hand seeding is encouraged whenever possible to aid in controlling erosion on construction sites. Seeding shall be applied to areas intended to be left dormant for a year or more, such as soil berms.

LIMITATIONS

 Hand seeding should be followed by mulching and/or installation of coir netting, erosion control blankets or mats.  This BMP should not be used during months when seed germination will not occur.

 Select seed mixes appropriate to the season and site conditions. Permit conditions and/or sensitive locations may require special seed mixes.  Grade as needed and feasible to permit the use of equipment for seedbed preparation.  Install needed erosion control practices, such as sediment basins, diversion dikes and channels, prior to seeding. Divert concentrated flows away from seeded areas.  Surface roughening: If the area has been recently loosened or disturbed, no further roughening is required. When the area is compacted, crusted or hardened the soil shall be loosened with discing, raking or harrowing.  Spread seed uniformly and according to manufacturer’s recommendations.  Straw mulch, erosion control blankets or mulch and tackifiers/soil binders should be applied over the seeded areas.

10.27 BMP: HAND SEEDING (continued)

BMP MAINTENANCE

 Inspect during seed establishment period. Re-see, due to mortality, as necessary. Areas which fail to establish cover adequate to prevent sheet and rill erosion will be reseeded as soon as such areas are identified. Spot seeding can be done on small areas to fill in bare spots where grass did not grow properly.

BMP REMOVAL

10.28 BMP: HYDROSEEDING

DESCRIPTION

Hydroseeding is broadcasting grass seed, tackifier, wood fiber mulch and water on disturbed areas using a hydroseeding machine. This BMP is used to reduce the potential for soil becoming water or air borne, to reduce erosion after vegetation is established, provide vegetative buffers and to aid in habitat protection. Seeding with appropriate seed mixes will also help discourage colonization by non-native and invasive plant species.

APPLICATIONS

Hydroseeding may be used after soil disturbance is completed at construction sites and/or on bare slopes.

LIMITATIONS

 Hydroseeding should not be used on streambanks or in areas subject to scour.  This BMP should not be used during months when seed germination will not occur.

 Select seed mixes appropriate to the season and site conditions. Permit conditions and/or sensitive locations may require special seed mixes.  Install needed erosion control practices, such as sediment basins, diversion dikes and channels, prior to hydroseeding. Divert concentrated flows away from hydroseeded areas.  Surface roughening: If the area has been recently loosened or disturbed, no further roughening is required. When the area is compacted, crusted or hardened the soil shall be loosened with discing, raking or harrowing.  Spread hydroseed mix uniformly and according to manufacturer’s recommendations.  Cover hydroseeded areas with other methods as needed.

BMP MAINTENANCE

 Inspect during seed establishment period. Re-see, due to mortality, as necessary. Areas which fail to establish cover adequate to prevent sheet and rill erosion will be reseeded as soon as such areas are identified. Spot seeding can be done on small areas to fill in bare spots where grass did not grow properly.

10.29 BMP: HYDROSEEDING (continued)

BMP REMOVAL

10.30 BMP: LARGE WOODY DEBRIS

DESCRIPTION

Large woody debris is any large piece of woody material generally defined as 6 inches and larger in diameter and at least 10 feet long, including the trunk and root mass, including stumps or rootwads.

APPLICATIONS

When incorporating woody material into projects, it is necessary to identify the desired performance and habitat benefits. Each project must be specifically tailored to meet the objectives identified for the habitat and any structures to be protected. It can be used in combination with other BMPs.

LIMITATIONS

 when specific design requirements and desired habitat benefits have not been identified.  in water bodies until all necessary permits have been obtained.  Refer to “Streambank Stabilization” BMP for installation methods.

 Guidelines will vary based on existing site conitions, size and shape of the wood, forces exerted by moving water, etc.  Construct in accordance with design and permit conditions.

BMP MAINTENANCE

 Monitor large woody debris installed to ensure it remains as built. Consult as necessary for adjustments and/or modifications to large woody debris installations.

BMP REMOVAL

10.31 BMP: LIVE POLE DRAIN

DESCRIPTION

A live pole drain is a biotechnical and reclamation technique intended to drain excess moisture away from an unstable site. The plants used to construct the bundles (willow) will sprout and grow, with the moisture continuing to drain from the lower end. The bundles of cuttings are usually placed in shallow trenches in a manner that they intersect and collect excessive slope moisture. That excess water is then allowed to drain onto a stabilized area.

APPLICATIONS

This BMP may be used on unstable slopes, landslide repairs, and small slumping gullies.

LIMITATIONS

 Live pole drains are not effective in larger, well defined channels with concentrated flows, as the pole drains will simply plug the channel and cause more erosion as the channel adjusts to maintain capacity.  Installation should be conducted at times of the year when weather conditions are cool and moist and the plant material is dormant.

Install the drains in the areas of seepage, either by excavating a shallow trench or utilizing an existing drainage gully, so the drains intercept and control the excess moisture. Use wattle/fascine techniques to construct the bundles. The bundles should be tied tightly with twine or rope. Place the bundle of cuttings in the trench. Construct side drains as needed. Key the bundles into each other by jamming the ends firmly together.

Use construction stakes and/or live stakes to hold the fascines in place. Insert the stakes adjacent to the rope ties for additional support. Stake the pole drains at 3-6 foot intervals. Lightly backfill the bundles with native soil. Some twigs and branches should be left above the ground as the willow material requires some sunlight exposure to grow.

BMP MAINTENANCE

 Regular inspection and maintenance should be conducted, particularly during the first year.  Failures of fill or drainage structures should be corrected immediately.

10.32 BMP: LIVE POLE DRAIN (continued)

BMP REMOVAL

 BMP removal is not necessary.

10.33 BMP: LIVE STAKING

DESCRIPTION

Live staking involves the insertion of live, vegetative cuttings into the ground in a manner that allows the cutting (stake) to take root and grow. This BMP is used to reduce the potential for soil to become water borne, to reduce water velocity/erosive forces, and to aid in habitat protection.

APPLICATIONS

This BMP may be used to repair small slips and slumps, to reinforce or enhance stream banks, and to anchor and enhance the effectiveness of wattles, fascines, straw logs and other erosion control materials. It may also be used in conjunction with approved rip rap installations (vegetated rip rap).

LIMITATIONS

 where vegetation growth will interfere with maintenance or facility access.  where vegetation growth will create safety issues.  for immediate soil stabilization results.

Live staking must be implemented during the dormancy period of chosen plant species, late fall to early spring. If native willows or cottonwood are not found in the vicinity, live staking may not be a good option. Cuttings should generally be ¾ inch in diameter or larger depending on the species. Cuttings of small diameter (up to 1- ½ inches) shall be 18 inches long minimum. Poles should be 1.5-3.5 inches diameter and 6-8 feet long. The actual length of cuttings depends on the application but the cutting should be long enough to reach into moist soils in mid-summer or the capillary fringe.

Stakes must not be allowed to dry out. All cuttings should be soaked in water for a minimum of 24 hours. Soaking significantly increases the survival rate of the cuttings, however they must be planted the same day they are removed from water.

Use an iron stake or bar to make a pilot hole in firm soil. Plant the stakes butt-ends into the ground, with the leaf bud scars or emerging buds always pointing up. Be careful not to damage the buds, strip the bark or split the stake during installation. The stakes should not be planted in rows or at regular intervals, but at random in the most suitable places at a rate of 2-5 cuttings/square yard.

10.35 BMP: LIVE STAKING (continued)

Set the stake as deep as possible into the soil, preferably with 80 percent of its length into the soil and in contact with mid-summer moist soils. The stake should protrude only to a maximum of one-quarter its length above the ground level to prevent it from drying. Stakes should be cut so that cutting extends above competing herbaceous vegetation. At least 2 buds and/or bud scars shall be above the ground after planting. It is essential to have good contact between the stake and soil for roots to sprout. Tamp the soil around the cutting. Do not fertilize.

BMP MAINTENANCE

 Periodic inspection, repair and maintenance will be done in accordance with permit requirements. If no permits are required, vegetation will be monitored for the first two years or until the vegetation is established.  Staked area may need to be watered during summer months.

BMP REMOVAL

BMP: MULCHING

DESCRIPTION

Mulching is the application of rice or sterile straw, wood chips, leaf litter, redwood duff, or other suitable materials on the soil surface applied manually or by machine. This BMP is used to reduce the potential for soil becoming water or air borne, and to encourage vegetation establishment.

APPLICATIONS

This BMP may be used to provide protection to the soil surface and to protect newly seeded areas. This BMP may be used in combination with plantings.

LIMITATIONS

 Mulch may not adhere well to slopes steeper than 2:1.  Mulch should not be placed in water bodies or in ditches where water flow is continuous.

 Mulch should be applied so that the soil is covered enough to allow seeds to protect against erosion, but still allow seeds to germinate.  Native mulches (redwood duff, leaf litter, etc.) are preferred in sensitive areas.  In areas subject to runoff or wind erosion, mulch shall be secured into the soil by mechanical or manual crimping, anchoring with branches, or other appropriate methods.

BMP MAINTENANCE

 Periodic inspection should be conducted, and mulch reapplied in areas where missing.

BMP REMOVAL

10.39 BMP: RIP RAP

DESCRIPTION

Rip rap is a structural method appropriate for supporting slopes and/or reducing erosion in areas where biotechnical methods are unsuitable and where engineered retaining structures are unnecessary.

APPLICATIONS

Rip rap may be used to stabilize steep slopes with seepage problems and/or unstable soils that need armoring to prevent sloughing. This BMP shall only be used as a last resort in locations where planting or other stabilizing methods are impracticable. Rip rap may also be used in combination with biotechnical BMPs.

Rip rapped areas should be evaluated for finishing with topsoil and revegetation to improve the drainage capacity of the fill and the stability of the rip rap matrix.

LIMITATIONS

 Rip rap shall not be used as a stand-alone method of streambank stabilization.  Permits must be obtained prior to placing any rip rap below the mean high water line of any water body, or in other sensitive areas.

 Perform live staking or pole planting during rip rap placement as appropriate.  Place rip rap to its full thickness in one operation.  The toe of the riprap slope should be keyed to a stable foundation at its base.  Schedule topsoil and revegetation finish work at an appropriate time or year.

BMP MAINTENANCE

 Riprap should be inspected periodically for scour or dislodged stones and repairs made immediately.

BMP REMOVAL

BMP: ROLLING DIP

DESCRIPTION

Rolling dips are ridges or ridge-and-channels constructed diagonally across a sloping road or utility right-of-way that is subject to erosion to limit the accumulation of erosive volumes of water on roads by diverting surface runoff at designated intervals.

APPLICATIONS

Rolling dips are gently sloping excavations running diagonally across the road surface, and are appropriate for winter use on unpaved roads and in areas prone to inundation due to culvert plugging. Rolling dips are much easier to traverse and require less maintenance than waterbars.

LIMITATIONS

 Never outlet rolling dips onto unprotected fill slopes. Install energy dissipaters or overside drains at outlet ends.  Use gravel to stabilize the diversion where significant vehicular traffic is anticipated.  Rolling dips should not be constructed in areas of high speed vehicle travel.

 Rolling dips should be built at an angle of 45 to 60 degrees from the centerline.  The diversion should have a positive grade of 2% minimum.  For rolling dips the height from channel bottom to the top of the settled ridge shall be 18 inches and the side slopes of the ridge shall be 2:1 or flatter where practicable.  The distance it takes for unrocked, unprotected running surface of a nearby road to develop a 1 inch rill is a rough measure of the appropriate spacing distance.  Signs alerting motorists to the dip or waterbar shall be installed in both directions.

BMP MAINTENANCE

 Periodically inspect waterbars and rolling dips. Inspect after every heavy rainfall for erosion damage. Immediately remove sediment from the flow area.  Check outlet areas and make timely repairs as needed.

10.43 BMP: ROLLING DIP (continued)

BMP REMOVAL

ADDITIONAL RESOURCES

Handbook for Forest and Ranch Roads, Mendocino County Resource Conservation District, June 1994.

BMP: SANDBAG

DESCRIPTION

A sandbag is a pre-manufactured cloth or plastic bag filled with sand or gravel. Sandbags can be used to keep water away from work areas and unstable slopes, and to construct curb inlet sediment barriers. Sandbags are also used as protection against flooding, as ballast, and in the construction of cofferdams and clean water bypasses.

APPLICATIONS

This BMP may be used during emergencies to control the flow and level of water. it may be used during construction to form dewatered areas such as cofferdams and clean water bypasses.

LIMITATIONS

 where prohibited by permit conditions.  as a permanent structure.

 When used in water bodies, this BMP must be used in accordance with permit conditions.  Secure ends of sandbags to ensure material does not scatter.  When used as a barrier, stack bags tightly together and in alternative (brick- layer) fashion.

BMP MAINTENANCE

 During construction, inspect daily during the workweek. Schedule additional inspections during storm events. Make any required repairs.  Replace damaged sandbags.  Remove sediment when deposits reach ½ the height of the sandbag barrier.

BMP REMOVAL

 Evaluate site to determine when BMP is no longer needed.  Remove sediment buildup in front of BMP.  Remove BMP, recycle and/or re-use if applicable.  Revegetate area disturbed by BMP removal.  Material in sandbags may be spread on slopes and stable areas where allowed by permit conditions. 10.46

BMP: SILT FENCE

DESCRIPTION

A silt fence is a temporary sediment barrier consisting of fabric stretched across and attached to supporting posts and entrenched into the soil. It is generally installed perpendicular to the flow direction to slow or stop water and to allow perimeter filtration, settling of soil particles, and to reduce water velocity.

APPLICATIONS

This BMP may be used for perimeter protection (around construction work sites, slide debris stockpiles, etc.). It may be used in combination with other BMPs.

LIMITATIONS

 where rock or hard surfaces prevent full and uniform anchoring of the barrier.  directly in streams or water courses.  around drop inlets or in front of storm drain inlets.  as a diversion dam.

 Place silt fence along contours.  Stakes or posts should be to the downhill side of the fence.  The bottom of the fabric must be continuously and securely anchored for its entire length to prevent undermining.  Increase the elevation at the ends of the BMP installation to prevent “end runs.”

BMP MAINTENANCE

 During construction, inspect daily during the workweek. Schedule additional inspections during storm events. Make any required repairs.  Replace damaged sections.  Remove sediment when deposits reach ½ the height of the silt fence.

BMP REMOVAL

 Evaluate site to determine when BMP is no longer needed.  Remove sediment buildup in front of BMP.  Remove BMP, recycle and/or re-use if applicable.  Revegetate area disturbed by BMP removal. 10.47 BMP: STRAW ROLL, STRAW LOG, COIR LOG

DESCRIPTION

Straw rolls/logs are manufactured from straw wrapped in netting. Coir logs are similar, but are filled with coconut fiber rather than straw. The logs are placed and staked in shallow trenches along the contour of newly constructed or disturbed slopes. They can be used to provide perimeter protection, settling, reduction in water velocity/erosive forces and habitat protection.

APPLICATIONS

The BMP may be used for temporary soil stockpile protection, drop inlet protection, temporary check dams, bank or slope stabilization, and streambank toe protection. This BMP may be used for perimeter sediment control, and is preferred over silt fencing and straw bales. It may also be used to replace missing sections of earthen berms (example: above new ditch relief culverts).

Straw rolls/logs should be manufactured of rice straw or a sterile (non-seed bearing) straw to prevent the introduction of non-native grasses. Polypropylene or coir netting is preferred over plastic netting.

LIMITATIONS

 where flow volume or water velocity inhibit its usefulness.

 Logs are placed in 2 to 3 inch deep trenches and staked along the contours of newly constructed or disturbed slopes.  Log spacing depends on soil type and slope steepness.  Adjacent logs shall be tightly abutted to prevent water flow and gully formation between logs.  Ensure that logs are in contact with the ground in the trenches to prevent water flow under logs.  Live staking may be used in conjunction with logs.

BMP MAINTENANCE

 During construction, inspect daily during the work week.  Schedule additional inspections during storm events.  Make any required repairs immediately.  For perimeter control installations (securing spoils, etc.), remove sediment deposits when they reach ½ the height of the log/roll.

10.49 BMP: STRAW LOG, STRAW ROLL, COIR LOG (continued)

BMP REMOVAL

 Remove sediment buildup in front of BMP.  Revegetation of the site may be necessary.  Dispose of netting properly. Straw or coir filling may be used as mulch.  BMP removal may not be necessary.

BMP: STREAMBANK STABILIZATION

DESCRIPTION

This BMP utilizes native materials (large woody debris, vegetation, etc.) to stabilize streambanks. Streambank stabilization activities require permits.

APPLICATIONS

Streambank stabilization techniques are appropriate adjacent to water bodies, on shallow slope failures, and in any location where native revegetation and/or natural construction materials and finishes are desired.

LIMITATIONS

 without identifying potential impacts to upstream and downstream banks, structures and facilities.  in or adjacent to water bodies until all necessary permits have been obtained.

 Guidelines will vary based on existing site conditions, size and shape of woody materials, forces exerted by moving water, etc.  Construct in accordance with design and permit conditions.

BMP MAINTENANCE

 Monitor finished streambanks to ensure stability and vegetative growth. Consult as necessary for adjustments and/or modifications to streambank stabilization installations.

BMP REMOVAL

ADDITIONAL RESOURCES

Bio Draw 1.0, Compendium of Biotechnical Soil Stabilization Solutions, Salix Applied Earthcare, 2000.

Guidelines for Bank Stabilization Projects in the Riverine Environments of King County, King County, Washington, Department of Public Works, June 1993.

10.53 ROOTWAD REVETMENT DETAIL ROOTWAD REVETMENT W/VEG RIP RAP BMP: SURFACE ROUGHENING

DESCRIPTION

Surface roughening is a technique for roughening a bare soil surface with furrows running across the slope, stair stepping, or tracking with construction equipment. Surface roughening is intended to aid the establishment of vegetative cover from seed, to reduce runoff velocity and increase infiltration, and to reduce erosion and provide for sediment trapping.

APPLICATIONS

All construction slopes require surface roughening to facilitate long-term stabilization with vegetation, particularly slopes steeper than 3:1.

LIMITATIONS

Slopes may be impossible to get machinery on due to steepness of slope or difficult access. Hand raking across the slope may be the only way to roughen the surface.

 on slopes with a rock surface.  unless simultaneous revegetation/seeding is planned.

Cut Slope Roughening:

 Stair-step grade or groove the cut slopes that are steeper than 3:1.  Use stair-step grading on any erodible material soft enough to be ripped with a bulldozer. Slopes consisting of soft rock with some subsoil are particularly suited to stair-step grading.  Make the vertical cut distance less than the horizontal distance, and slightly slope the horizontal position of the "step" in toward the vertical wall.  Groove the slope using machinery to create a series of ridges and depressions that run across the slope, on the contour.

Fill Slope Roughening:

 Place fill slopes with a gradient steeper than 3:1 in lifts not to exceed 8 inches, and make sure each lift is properly compacted.  Ensure that the face of the slope consists of loose, uncompacted fill 4-6 inches deep.  Use grooving or tracking to roughen the face of the slopes, if necessary.

10.58 BMP: SURFACE ROUGHENING (continued)

 Apply seed, fertilizer and straw mulch then track or punch in the mulch with the bulldozer.  Do not blade or scrape the final slope face.

Roughening With Tracked Machinery:

 Limit roughening with tracked machinery to soils with a sandy textural component to avoid undue compaction of the soil surface.  Operate tracked machinery up and down the slope to leave horizontal depressions in the soil. Do not back-blade during the final grading operation.  Immediately seed and mulch roughened areas to obtain optimum seed germination and growth.

BMP MAINTENANCE

 During construction, inspect BMPs daily during the workweek.  Schedule additional inspections during storm events. Check for erosion and sloughing, and make any required repairs.

BMP REMOVAL

10.59 BMP: TIMING OF WORK

DESCRIPTION

In general, routine maintenance and construction activities that remove vegetative soil cover and/or will potentially release sediment into stormwater will be conducted during the dry season (approximately April through October).

Activities that are subject to permit requirements will be conducted during the period authorized by the permits.

Bare soil surfaces resulting from maintenance and/or construction activities shall be covered with suitable erosion controls (fabrics, hydroseeding, mulch, etc.):

 No later than 3 days following the disturbance during the rainy season (approximately November through March).  No later than 7 days following the disturbance during the dry season (approximately April through October).

Every effort shall be made to immediately cover bare soil surfaces resulting from maintenance and/or construction activities prior to storms.

10.62 BMP: VEGETATIVE BUFFER

DESCRIPTION

A vegetative buffer is a strip of vegetation adjacent to sensitive areas, ditches, pavement and water bodies. This BMP prevents soil from becoming water borne, and may help restore shallow slope failures by trapping soil and debris.

APPLICATIONS

This BMP may be used adjacent to ditches and/or sensitive areas and water bodies, parallel to roadways, parking lots, etc. It may be used in combination with other BMPs.

LIMITATIONS

 if it creates a potential public safety hazard.

 Existing vegetation shall be preserved as a buffer to the greatest extent possible.  Use live staking, brush layering, wattles/fascines and/or seeding methods to restore vegetative buffers after disturbances.

BMP MAINTENANCE

 Mow, trim or selectively harvest the vegetative buffer in accordance with applicable permits and/or approved vegetation management plans.  Revegetate as necessary.

BMP REMOVAL

10.63 BMP: WATTLES/FASCINES

DESCRIPTION

Wattles and fascines are live branch cuttings, usually willows, bound together into long, tubular bundles used to stabilize slopes and stream banks. Both wattles and live fascines are true biotechnical practices. The live branches and live stakes provide the biological element while the stems, rope ties and wedge shaped wooden stakes all combine to provide the structural elements. Fascines differ from wattles in that the branch cuttings all point in the same direction in fascines, where they may point in either direction in wattles. Wattles are typically aligned on contour, where fascines are angled slightly upslope (and thus tend to produce more vigorous growth).

APPLICATIONS

Wattles/fascines may be used for long slopes, road fills, road cuts, gullies or slumped areas, eroded slopes or eroding stream banks. May be used to repair small earth slips and slumps or to protect slopes from shallow slides 1-2 feet deep. Wattles/fascines may be used to stabilize entire cut or fill slopes or localized gully areas of slopes, or may be installed on newly built slopes or as a remedial action on existing slopes. This technique is useful on slopes requiring other planting materials such as woody vegetation, transplants and grasses. Wattles/fascines enhance conditions for natural invasion and the establishment of other plants from the surrounding plant community.

LIMITATIONS

 Plant material harvest and installation must be performed during the dormant season, late fall through early spring.  Where increased infiltration may cause slope failures, fascines should be used instead of wattles to ensure positive drainage.

Wattles/fascines should be pre-soaked for 24 hours or installed on the same day they are harvested and prepared. Wattles/fascines must be stored in the shade and under cover, preferably in water. Use site reconnaissance to identify species and site conditions on adjacent sites and compare their conditions to the construction site. Planting will be more successful as the soil, site conditions, and species selected match stable and vegetated nearby sites.

Cuttings shall be tied together to form bundles, tapered at each end, 6-30 feet in length, depending on site conditions or limitations in handling. The completed bundles should be 6-12 inches in diameter. Stagger the cuttings in the bundles so that the tips are evenly distributed throughout the length of the bundle.

10.64 BMP: WATTLES/FASCINES (continued)

Wattle/fascine bundles shall be compressed and tightly tied with rope or twine of sufficient strength and durability. Polypropylene ‘tree rope’ approximately 3/16 inch in diameter provides the necessary strength and durability. Bundles shall be tied 12-15 inches apart.

Table 1: General Installation Guidelines

Slope Slope Length Between Wattles/Fascines (H:V) (feet)

1:1 to 1.5:1 3-4

1.5:1 to 2:1 4-5

2:1 to 2.5:1 5-6

2.5:1 to 4:1 6-8

3.5:1 to 4:1 8-12

4.5:1 to 5:1 10-20

Perform any slope repairs prior to wattle/fascine installation.

Beginning at the base of the slope, dig a trench on contour. The trench shall be shallow, about ½ the diameter of the wattle. The trench width will vary from 12-18 inches depending on the slope angle. Place the wattles immediately after trenching to reduce desiccation of the exposed soil. Wattles shall be staked firmly in place with one row of construction stakes on the downhill side of the wattling, not more than 3 feet apart. second row of stakes shall be placed through the wattles, near the ties, at not more than 5 feet apart. Overlap the tapered ends of adjacent wattles so the overall wattle thickness of the wattle is uniform. Two stakes shall be used at each bundle overlap such that a stake may be driven between the last two ties of each wattle.

Live stakes, if specified, are generally installed on the downslope side of the bundle. Drive the live stakes below and against the bundle between the previously installed construction stakes. Proper backfilling is essential to the successful rooting of the wattles. Backfill wattles with soil from the slope or trench above. The backfill shall be worked into the wattle interstices and compacted behind and below the bundle by walking on and working from its wattling terrace.

Repeat the proceeding steps to the top of the slope. Place moist soil along the sides of the live bundle. The top of the bundle should be slightly visible when the installation is completed. Plant the slope as specified.

10.65 BMP: WATTLES/FASCINES (continued)

Seed and mulch slope, if specified. Shallow slopes, generally 3:1 or flatter may be seeded and mulched by hand. Steeper slopes can have seed applied hydraulically and the mulch should be anchored with tackifier or other approved methods.

BMP MAINTENANCE

 Regular inspection and maintenance of wattle installations should be conducted, particularly during the first year.  Staked area may need to be watered during summer months.  Rills and gullies around or under wattles shall be repaired immediately.

BMP REMOVAL

 BMP removal is not necessary. BMP: SPECIES PROTECTIONS - MIGRATORY BIRDS

DESCRIPTION

Migratory birds and their nests are protected by Federal and State laws and regulations. It is unlawful to “pursue, hunt, take, capture, kill, attempt to take, capture, or kill,…any migratory bird, any part, nest, or eggs of any such bird…” Inactive nests, other than raptor nests, may be removed. Raptor nests are protected by the California Department of Fish and Game, and require a special permit to remove.

APPLICATIONS

This BMP may be used to avoid impacts to nesting birds protected under the Federal Migratory Bird Treaty Act and California Department of Fish and Game Code.

LIMITATIONS

 Some sites contain dense vegetation and cannot be adequately surveyed to determine nesting bird absence.  If a site cannot be adequately surveyed, work at the site must be scheduled between August 15 and October 15.

 Time projects and maintenance activities to avoid nesting season.  If work occurs during nesting season, it must be preceded by a nesting bird survey by a qualified biologist within 15 days prior to the beginning of work activities.  If nesting birds are detected, a 50-foot exclusion zone (200-foot for raptors) shall be established for protection. If the exclusion zone is located within the immediate work area, construction will be delayed until the young have fledged and left the nest.  At no time can a raptor nest be removed without Fish and Game approval.

BMP MAINTENANCE

 Some projects may require daily or weekly nesting bird surveys.

BMP REMOVAL

 Any flags, flagging tape, or exclusionary fencing shall be removed immediately after the completion of work activities. BMP: SPECIES PROTECTIONS - CALIFORNIA RED-LEGGED FROG

DESCRIPTION

The California red-legged frog (CRLF) is protected as a threatened species under the California Endangered Species Act and as a Species of Special Concern by Fish and Game. In areas with the potential for CRLF occurrence, special protections must be followed to avoid impacts to CRLF.

APPLICATIONS

This BMP may be used to avoid impacts to California red-legged frog.

LIMITATIONS

 Some sites contain dense vegetation and cannot be adequately surveyed to determine CRLF absence.

 Time projects and maintenance activities to avoid the peak CRLF active period (March through July).  Projects in areas with the potential for CRLF occurrence must be surveyed and monitored by a qualified biologist.  Install exclusionary fencing around the work area when necessary. o Exclusionary fencing must be trenched into the soil at least 4 inches and the soils must be carefully compacted against both sides of the fence for its entire length. If trenching is not feasible, would be substantially damaging to SFGS habitat, or would cause an increased risk of take, fencing may be secured with U-shaped nails or sandbags and a biological monitor would need to continually monitor the fence for the duration of work activities. o Fences should be installed with “turn-arounds” at the ends furthest from wetland habitat and at any access openings needed in the fencing, in order to redirect CRLF away from openings. o Exclusionary fencing must be at least 36 inches tall to minimize the possibility that frogs will be able to jump over the fencing.

BMP MAINTENANCE

 Fences must be inspected at least twice weekly AND after any significant rain event.  Repairs to the fencing must be made within 24 hours of the inspection that first noticed a fencing breach, such as a broken stake, a hole in the fencing material, material pulled away from a stake, and objects, rain, wind, or sediment that cause fences to sag which would allow CRLS to overtop the fence.

BMP REMOVAL

 Any flags, flagging tape, or exclusionary fencing shall be removed immediately after the completion of work activities.  Any areas disturbed by fence installation and removal shall be returned to their original condition as much as possible and revegetated with native plants if applicable. BMP: SPECIES PROTECTIONS - SAN FRANCISCO GARTER SNAKE

DESCRIPTION

The San Francisco garter snake (SFGS) is protected as an endangered species under the State and Federal Endangered Species Acts and as a Fully Protected species by Fish and Game. In areas with the potential for SFGS occurrence, special protections must be followed to avoid impacts to SFGS.

APPLICATIONS

This BMP may be used to avoid impacts to San Francisco garter snake (SFGS).

LIMITATIONS

 Some sites contain dense vegetation and cannot be adequately surveyed to determine SFGS absence.

 Time projects and maintenance activities to avoid the peak SFGS active period (March through July).  Projects in areas with the potential for SFGS occurrence must be surveyed and monitored by a qualified biologist.  Install exclusionary fencing around the work area when necessary. o If at all possible, exclusionary fencing should be installed during SFGS inactive period. o Exclusionary fencing must be trenched into the soil at least 4 inches and the soils must be carefully compacted against both sides of the fence for its entire length. If trenching is not feasible, would be substantially damaging to SFGS habitat, or would cause an increased risk of take, fencing may be secured with U-shaped nails or sandbags and a biological monitor would need to continually monitor the fence for the duration of work activities. o Exclusionary fencing must be installed with the fence stakes placed on the upland side of the fence (opposite the normal requirement for sediment control) to prevent the snakes from using the stakes to maneuver over the fencing. o Vegetation on the side away from the construction footprint of the fence must be mowed or manually cut immediately following fence installation to lower its canopy height. This vegetation must then be maintained at a height of 4 inches or less during the growing season. o Fences should be installed with “turn-arounds” at the ends furthest from wetland habitat and at any access openings needed in the fencing, in order to redirect SFGS away from openings. BMP MAINTENANCE

 Fences must be inspected at least twice weekly AND after any significant rain event.  Repairs to the fencing must be made within 24 hours of the inspection that first noticed a fencing breach, such as a broken stake, a hole in the fencing material, material pulled away from a stake, and objects, rain, wind, or sediment that cause fences to sag which would allow SFGS to overtop the fence.

BMP REMOVAL

 Any flags, flagging tape, or exclusionary fencing shall be removed immediately after the completion of work activities.  Any areas disturbed by fence installation and removal shall be returned to their original condition as much as possible and revegetated with native plants if applicable. BMP: SPECIES PROTECTIONS - SAN FRANCISCO DUSKY-FOOTED WOODRAT

DESCRIPTION

The San Francisco dusky-footed woodrat (SFDW) is protected as a Species of Special Concern by the California Department of Fish and Game (CDFG). Woodrats are mostly nocturnal and occupy stick houses up to 8 feet tall. Their nests occur within the stick houses, and their breeding season extends from December to September.

APPLICATIONS

This BMP may be used to avoid impacts to San Francisco dusky-footed woodrat (SFDW).

LIMITATIONS

 Some sites contain dense vegetation and cannot be adequately surveyed to determine SFDW nest absence.  Nests that cannot be avoided must be relocated or mitigated for under the direction of CDFG.

 A preconstruction survey for SFDW nests shall be conducted by a qualified biologist within two weeks prior to work activities in areas with potential SFDW habitat.  In the event a SFDW nest is found in the work area, a 10-foot buffer will be marked, or exclusionary fencing will be erected, to exclude the nest from work activities. If the nest is less than 10-feet from the work area, a qualified biologist will remain on-site during work activities to ensure the nest is not impacted.  Removal and/or trimming of riparian and wetland vegetation shall be minimized to the maximum extent possible.

BMP MAINTENANCE

 A qualified biologist shall inspect the BMPs prior to construction and conduct an educational training session to brief crews on protections for SFDW.

BMP REMOVAL

 Any flags, flagging tape, or exclusionary fencing shall be removed immediately after the completion of work activities. BMP: SPECIES PROTECTIONS - SPECIAL STATUS PLANTS

DESCRIPTION

Special status plants are those that are protected by State or Federal Endangered Species Acts, or are listed as Rare, Threatened, or Endangered by the California Native Plant Society.

APPLICATIONS

This BMP may be used to avoid impacts to special status plants.

LIMITATIONS

 Many sensitive plants may not be easily identifiable unless surveys are conducted during peak blooming periods.  Areas of dense vegetation may be difficult to adequately survey.

 In order to maximize the likelihood of locating special status plant species, a minimum of two special status plant surveys shall be conducted during the peak blooming periods (typically April through May) when the plants are more easily identifiable.  Any special status species located in a project site shall be clearly marked and avoided or, if necessary, excluded from the work area with exclusionary fencing.

BMP MAINTENANCE

 A qualified biologist shall inspect the BMPs prior to construction and conduct an educational training session to brief crews on protections for special status plants.

BMP REMOVAL

 Any flags, flagging tape, or exclusionary fencing shall be removed immediately after the completion of work activities.

APPENDIX A COASTAL ZONE MAP APPENDIX B WATER RESOURCES MAPS APPENDIX C INTERIM DPW DEBRIS STORAGE LOCATIONS APPENDIX D ENDANGERED SPECIES INFORMATION APPENDIX E NOTIFICATION FORMS APPENDIX H REVISIONS & ADDITIONS