Vegetating Disturbed Road & Stream Banks. By Mike Fournier NRCS Resource Conservationist

Transcription

1 Vegetating Disturbed Road & Stream Banks By Mike Fournier NRCS Resource Conservationist

2 Clearly Identify The Problem

3 Project Objectives Clearly Define Objectives Before Work Starts Determine Whether Project Will Revegetate Or Restore Native Vegetative Cover Document How Success Will Be Measured

4 Threats to Property & Lives Assess On Site Risk Document Distances Locate Various Intensity Flood Plains

5 Site Limitations Soils Slope Solar Exposure Water Historic Climatic Factors Necessity of Site Preparation Site Accessibility Maintenance Needs & Availability Threats to Success

6 Time Constraints Short Term Cover Needs Target Vegetative Cover Maintenance

7 Cultural Limitations Aesthetics Native vs. Exotic Plant Issues Jurisdictional Cultural Resource

8 Cost The Greater The Project Complexity, The Greater The Cost! Your Objectives Must Reflect Your Budget!

9 1. Do Nothing After Excavation 2. Grass Seeding 3. Soil Bio- Engineering Vegetative Alternatives For Road Banks

10 Stream Bank Stabilization Alternatives

11 Considerations For Stream Bank Repair Elements Of Stream Formation 1. Watershed 2. Climatic Contributions 3. Geologic & Topographic Features 4. Stream Dynamics Stream Repair Practices

12 Watershed Influence Size Flow Path Valley Soils Current Land Uses Historic Land Uses

13 Climatic Elements Total Rainfall Total Snowfall Precipitation Patterns Total Days Of Frost Free Soil Seasonal Transitions

14 Geologic & Topographic Features Elevation Frequency And Location Of Bedrock Outcrops Terrain Slope Type & Texture of Bedrock In-Stream Aggregate Size

15 Stream Dynamics Every Stream Takes The Path Of Least Resistance As A Function of Energy Dissipation, A Stream Meanders Terrain Features Influence The Stream s Character

16 Stream Dynamics Stream Erosion Is Result Of The Stream Balancing Its Sediment Load There Is A Systematic Process Of Down Cutting Followed By Widening As A Streams Watershed Is Altered

17 Stream Dynamics A Stream s Cross Sectional Area Is Utilized To Better Understand Its Character All Stream Forming Elements Influence The Cross Section Regular Storm Events Are Used As Indicators Of Magnitude Remnant Flood Terraces Tell Of the Stream s Past

18 Soft vs. Hard Approaches Vegetative Approaches Are Usually Less Expensive Hard Structures Are Usually Longer Lasting Vegetative Solutions Are Usually More Aesthetically Appealing There Are Plenty Of Skilled Contractors Available To Install Hard Structures Adequate Materials Are Not Always Available For Hard Structures The Successful Establishment Of Vegetative Techniques Is At The Mercy OF The Weather Vegetative Approaches Have Added Benefit To Water Quality Properly Designed Hard Structures Don t Erode

19 Soft Bio-Engineering Utilizes Both Living & Dead Plant Material Utilmately Relies On Root Mass To Protect Against Erosion Can Be Designed To Be Visually Appealing Can Be Designed To Provide Added Benefit To Wildlife As Food & Cover

20 Soft Techniques 1. Rooted Plantings 2. Live Stakes 3. Live Fascines 4. Live Wattles 5. Branch Packing 6. Vegetated Geogrid 7. Brush Mattress 8. Dormant Posts 9. Live Siltation Traps 10.Reed Clumps

21 Hard These Structures Are Constructed With Rock, Concrete, Or Other Inert Materials We Often Look At These Structures As Permanent, Withstanding Environmental Challenges For >50 Years With The Rare Exception, These Techniques Are Installed Solely By Heavy Machinery

22 Hard Techniques 1. Rock Riprap 2. Jetties 3. Vanes / Barbs 4. Cross Vanes / Grade Stabilization Structures 5. J-Vane 6. Rock Gabions 7. Bulkheads 7.

23 Hybrids These Techniques Blend The Best Of Both Worlds: Durability, Function, Aesthetics, And Wildlife Benefit Contrary To What May Be Initially Thought, Cost Savings Is Not Realized Making This Choice; The Addition Of More Materials Usually Drives The Price Higher

24 Hybrid Techniques 1. Live Cribwalls 2. Joint Planting 3. Vegetated Rock Gabions 4. Geo-Grid Grid 5. Tree Revetments 6. Rootwads 7. Lunkers 8. Coconut Fiber Rolls