tools for stream restoration: morphology & structures

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Tools for Stream Restoration: Morphology & Structures Greg Jennings, PhD, PE, Jennings Environmental LLC

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Page 1: Tools for Stream Restoration: Morphology & Structures

Tools for Stream Restoration: Morphology & Structures Greg Jennings, PhD, PE, Jennings Environmental LLC

Page 2: Tools for Stream Restoration: Morphology & Structures

Fluvial Geomorphology: study of landforms and the fluvial processes that shape them

Page 3: Tools for Stream Restoration: Morphology & Structures

Fluvial Processes: associated with flowing water, including sediment erosion,

transport, and deposition

Page 4: Tools for Stream Restoration: Morphology & Structures

•  Channel (bed & banks) •  Floodplain •  Water •  Sediment •  Plants & animals

Stream: A system of fluvial forms & habitats

Photo Credit: Eve Brantley, Auburn University

Page 5: Tools for Stream Restoration: Morphology & Structures

Fluvial Forms •  Bar •  Channel •  Confluence •  Cutoff channel •  Delta •  Floodplain •  Gorge •  Gully •  Meander •  Oxbow lake •  Pool •  Riffle •  Stream •  Valley •  Waterfall •  Watershed

Page 6: Tools for Stream Restoration: Morphology & Structures

Sediment Deposition: bars, benches, fans, & floodplains •  Point bar •  Lateral bar •  Mid-channel bar •  Transverse bar •  Delta •  Alluvial fan •  Inner berm

Page 7: Tools for Stream Restoration: Morphology & Structures

Point Bar

Lateral Bar

Page 8: Tools for Stream Restoration: Morphology & Structures

Mid-channel Bar

Transverse Bar

Page 9: Tools for Stream Restoration: Morphology & Structures

Stream Morphology: size and shape of channel & floodplain (dimension, pattern, profile)

Page 10: Tools for Stream Restoration: Morphology & Structures

Floodplain

Left Bank Right Bank

Downstream

Terrace

Streambed

Thalweg

Page 11: Tools for Stream Restoration: Morphology & Structures

Incised Stream System: Floodplain Creation

Floodplain

Terrace

Page 12: Tools for Stream Restoration: Morphology & Structures

Colluvium: loose sediment transported by gravity and deposited down slope Alluvium: sediment deposited by flowing water in a channel or floodplain Alluvial valleys occur where sediment particles are dropped by slow-moving water

Valley type affects stream morphology

Page 13: Tools for Stream Restoration: Morphology & Structures

Valley Type II Moderately steep, gentle sloping side slopes often in colluvial valleys

From EPA Watershed Academy: Fundamentals of the Rosgen Stream Classification System

Valley Types: www.epa.gov/watertrain/stream_class

Page 14: Tools for Stream Restoration: Morphology & Structures

Valley Type VIII Wide, gentle valley slope with well-developed floodplain adjacent to river terraces

From EPA Watershed Academy: Fundamentals of the Rosgen Stream Classification System

Valley Types: www.epa.gov/watertrain/stream_class

Page 15: Tools for Stream Restoration: Morphology & Structures

Meandering Stream: Alluvial Forms

Point Bar

Scarp Bankfull Stage

Thalweg

Flow Downstream Floodplain

Riffle

Pool

Right Bank

Left Bank

Page 16: Tools for Stream Restoration: Morphology & Structures

Pool Cross-Section (Meandering Stream)

Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.

Page 17: Tools for Stream Restoration: Morphology & Structures

Bankfull Stage: “incipient flooding” “corresponds to the discharge at which channel maintenance is the most effective, that is, the discharge at which moving sediment, forming or removing bars, forming or changing bends and meanders, and generally doing work results in the average morphologic characteristics” (Dunne & Leopold,1978)

Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.

Page 18: Tools for Stream Restoration: Morphology & Structures

Bankfull Discharge

•  Flow fills active channel and spreads onto floodplain

•  Represents break between channel & floodplain processes

•  For channel in equilibrium, assumed to equal effective discharge

•  Typical Return Period 1 to 2 yrs

Page 19: Tools for Stream Restoration: Morphology & Structures

Bankfull

Page 20: Tools for Stream Restoration: Morphology & Structures

Bankfull

Page 21: Tools for Stream Restoration: Morphology & Structures

Bankfull

Page 22: Tools for Stream Restoration: Morphology & Structures

Channel Evolution (Succession) Response to incising forces

Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.

Page 23: Tools for Stream Restoration: Morphology & Structures

Bankfull Terrace

Page 24: Tools for Stream Restoration: Morphology & Structures
Page 25: Tools for Stream Restoration: Morphology & Structures

Equilibrium Controlling Variables • Width • Depth •  Slope •  Velocity • Discharge •  Flow resistance •  Sediment size •  Sediment load

Leopold et al (1964)

Page 26: Tools for Stream Restoration: Morphology & Structures

Dimension (cross-section)

•  Area •  Width •  Depth •  Width/Depth Ratio •  Entrenchment Ratio •  Bank Height Ratio

Page 27: Tools for Stream Restoration: Morphology & Structures

Dimension: Cross-Section

Page 28: Tools for Stream Restoration: Morphology & Structures

Riffle Dimensions

Bankfull

Wbkf

Abkf

Measure Bankfull Width (Wbkf) and Bankfull Area (Abkf)

Mean Depth, dbkf = Abkf / Wbkf

Width to Depth Ratio, W/d = Wbkf / dbkf

dbkf

Page 29: Tools for Stream Restoration: Morphology & Structures

Bankfull Width, Wbkf = 9.3 ft; Bankfull Area, Abkf = 13.9 ft2

Mean Depth, dbkf = Abkf / Wbkf = 13.9 / 9.3 = 1.5 ft

Width to Depth Ratio, W/d = Wbkf / dbkf = 9.3 / 1.5 = 6.2

Page 30: Tools for Stream Restoration: Morphology & Structures

Bankfull Width, Wbkf = 36 ft; Bankfull Area, Abkf = 112 ft2

Mean Depth, dbkf = Abkf / Wbkf = 112 / 36 = 3.1 ft

Width to Depth Ratio, W/d = Wbkf / dbkf = 36 / 3.1 = 11.5

Page 31: Tools for Stream Restoration: Morphology & Structures

Entrenchment Ratio, ER = Wfpa / Wbkf

Bankfull 2 x dmbkf

above thalweg

Wfpa

Wbkf

dmbkf

Wfpa = Width of Flood Prone Area measured at the elevation twice bankfull max depth above thalweg

Wbkf = Width of Bankfull Channel

Page 32: Tools for Stream Restoration: Morphology & Structures

ER = Wfpa / Wbkf = 75 / 15 = 5.0

Page 33: Tools for Stream Restoration: Morphology & Structures

Flood water flows onto floodplain several times each year

Rocky Branch Phase II Reach 2: Priority 2 (floodplain excavation, C channel)

Entrenchment Ratio = Wfpa / Wbkf = 90/20 = 4.5

Page 34: Tools for Stream Restoration: Morphology & Structures

Rocky Branch Phase II Reach 1: Priority 3 (floodplain excavation, Bc channel) Entrenchment Ratio = Wfpa / Wbkf = 40/20 = 2

Page 35: Tools for Stream Restoration: Morphology & Structures

Bank Height Ratio, BHR = LBH / dmbkf

Bankfull LBH

dmbkf = Max Depth from bankfull stage to thalweg

dmbkf

LBH = Low Bank Height (Max Depth to thalweg)

Page 36: Tools for Stream Restoration: Morphology & Structures

BHR = 5.3 / 2.5 = 2.1

Page 37: Tools for Stream Restoration: Morphology & Structures

1

10

100

1000

0.1 1 10 100

Cross-­‐section  Area  (sq  ft)

Drainage  Area  (sq  mi)

Hydraulic  Geometry  Regional  Curves

NC  Piedmont

NC  Mtn

MD  Alleghany

MD

NY

VT

OH  01

OH  05

OK

SW  OR

Pacific  NW

AZ

AZ  &  NM

Page 38: Tools for Stream Restoration: Morphology & Structures

y = 18.786x0.6724 R² = 0.99815

1.0

10.0

100.0

1000.0

0.1 1 10 100 1000

Cro

ss-S

ectio

nal A

rea

(squ

ar fe

et)

Drianage Area (square miles)

Concept NOT FOR DESIGN USE Auburn Alabama and Tuskegee NF Mini-Regional Relationship

Prepared by DAB 11-29-07

Mini Regional Relationship NC Rural Piedmont Curve NC Coastal Curve Power (Mini Regional Relationship)

Page 39: Tools for Stream Restoration: Morphology & Structures

Alluvial (low-gradient) streams naturally meander across a valley with a somewhat predictable pattern

Pattern (plan form)

Page 40: Tools for Stream Restoration: Morphology & Structures

Pool Run

Point Bar (deposition)

Glide

Riffle

Meandering Stream: Alluvial Forms

Page 41: Tools for Stream Restoration: Morphology & Structures

Oxbow Formation in Meandering

Streams

Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.

Page 42: Tools for Stream Restoration: Morphology & Structures

Chute cutoff across tight meander bend

Page 43: Tools for Stream Restoration: Morphology & Structures

Sinuosity = stream length / valley length K = 1850 / 980 = 1.9

Valley Length

Page 44: Tools for Stream Restoration: Morphology & Structures

Plan Form Relationships

Page 45: Tools for Stream Restoration: Morphology & Structures

Meander Length Ratio = meander length / width = 78/15 = 5.2 Meander Width Ratio = belt width / width = 57/15 = 3.8

Radius of Curvature Ratio = radius / width = 23/15 = 1.5

Meander Length

Belt Width

Page 46: Tools for Stream Restoration: Morphology & Structures

Stream Bedform Variability: Slope Substrate size Velocity Oxygenation Shear stress Habitats

Page 47: Tools for Stream Restoration: Morphology & Structures

www.wildlandhydrology.com

Page 48: Tools for Stream Restoration: Morphology & Structures

Ecosystem Restoration: “activities that initiate or accelerate the recovery of ecosystem health, integrity, and sustainability” (SER, 2004)

Page 49: Tools for Stream Restoration: Morphology & Structures

Planning a Stream Project: •  Goals? Stability, Habitat, Recreation? •  Constraints? Access, Land Availability, Utilities? •  Feasibility? Will it Work? •  Constructability? Equipment, Materials, Time/$?

Page 50: Tools for Stream Restoration: Morphology & Structures

1.  Channel & Floodplain Morphology

2.  In-stream Structures

3.  Habitats & Vegetation

4.  Site & Watershed Conditions

5.  Hydrologic & Hydraulic Analysis

6.  Implementation

7.  Monitoring, Maintenance, & Education

Restoration Components

Page 51: Tools for Stream Restoration: Morphology & Structures

1. Channel & Floodplain Morphology Dimension, Pattern, Profile, Floodplain Connection

2005 NCSU Rocky Branch 2009

Page 52: Tools for Stream Restoration: Morphology & Structures

High-quality “reference” streams serve as design templates

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Floodplain Structure •  Regular (every year) flooding to relieve stress

•  Floodwater retention & riparian wetlands

•  Stormwater discharge retention & treatment

Page 54: Tools for Stream Restoration: Morphology & Structures

Priority 1: lift channel

Incised Stream

Priority 2 & 3: lower floodplain

Stream Corridor Restoration: Principles, Processes, and Practices. 1998. Federal Interagency Stream Restoration Working Group.

Page 55: Tools for Stream Restoration: Morphology & Structures

2006 Town Creek Tributary 2007

Priority 1: Raise channel to existing valley and construct new meandering channel

Rain will come during and immediately following construction!

ER = 15; W/d = 12

Page 56: Tools for Stream Restoration: Morphology & Structures

2008 Town Creek Tributary

Entrenchment Ratio = Wfpa / Wbkf = 150/10 = 15

Page 57: Tools for Stream Restoration: Morphology & Structures

Priority 2: Excavate lower floodplain and construct new meandering channel

2008 White Slough 2010

ER = 6; W/d = 11

Page 58: Tools for Stream Restoration: Morphology & Structures

White Slough 2010

Entrenchment Ratio = Wfpa / Wbkf = 90/15 = 6

Page 59: Tools for Stream Restoration: Morphology & Structures

Priority 2: Excavate lower floodplain and construct new meandering channel

2004 NCSU Rocky Branch 2005

Page 60: Tools for Stream Restoration: Morphology & Structures

Flood water flows onto floodplain several times each year

Rocky Branch Phase II Reach 2: Priority 2 (floodplain excavation, C channel)

Entrenchment Ratio = Wfpa / Wbkf = 90/20 = 4.5

Page 61: Tools for Stream Restoration: Morphology & Structures

2003

2000

2003

2001

Page 62: Tools for Stream Restoration: Morphology & Structures

2005 NCSU Rocky Branch 2006

Priority 3: Excavate narrow floodplain benches in confined systems

ER = 2.2; W/d = 12

Page 63: Tools for Stream Restoration: Morphology & Structures

Rocky Branch Phase II Reach 1: Priority 3 (floodplain excavation, Bc channel) Entrenchment Ratio = Wfpa / Wbkf = 40/20 = 2

Page 64: Tools for Stream Restoration: Morphology & Structures

2008 NCSU Rocky Branch

Page 65: Tools for Stream Restoration: Morphology & Structures

Priority 3: Excavate narrow floodplain benches in confined systems

2009 Little Shades Creek 2010

ER = 1.6; W/d = 15

Page 66: Tools for Stream Restoration: Morphology & Structures

Entrenchment Ratio = Wfpa / Wbkf = 60/38 = 1.6

Page 67: Tools for Stream Restoration: Morphology & Structures

Riffle Morphology: Bankfull Width = 15 ft; Depth = 1.2 ft

Floodprone Width = 33 ft

Entrenchment Ratio, ER = 33/15 = 2.2

Page 68: Tools for Stream Restoration: Morphology & Structures

2. In-Stream Structures (Logs & Rocks) •  Streambank protection •  Habitat enhancement (pools, aeration, cover) •  Grade control •  Sediment transport

Page 69: Tools for Stream Restoration: Morphology & Structures

Structure Criteria: •  Natural materials •  Habitats & passage for aquatic organisms •  Natural sediment transport (alluvial systems)

Do you like these?

Page 70: Tools for Stream Restoration: Morphology & Structures

Boulder J-Hook Vane

Page 71: Tools for Stream Restoration: Morphology & Structures

Runaway Truck Ramp

Page 72: Tools for Stream Restoration: Morphology & Structures

Roaring River, Stone Mt State Park (2000-10) •  Trout Stream: Channel Realignment, Structures, Planting

10 years later

Page 73: Tools for Stream Restoration: Morphology & Structures

Boulder J-Hook Vane •  3-5 % arm slopes

•  20-25 degree arm angles

•  Boulder footers & non-woven geotextile

•  0.5 ft drops over j-hook inverts

Page 74: Tools for Stream Restoration: Morphology & Structures

Boulder Vane 20-25 degree angles

3-5 % arm slopes

20-25 degrees

3-5 % arm slopes

Page 75: Tools for Stream Restoration: Morphology & Structures

Chinking Boulders to Prevent Piping

Page 76: Tools for Stream Restoration: Morphology & Structures

Geotextile Curtain to Prevent Piping

Page 77: Tools for Stream Restoration: Morphology & Structures

Boulder

J-Hook Vane

Page 78: Tools for Stream Restoration: Morphology & Structures

Log J-Hook Vane

Page 79: Tools for Stream Restoration: Morphology & Structures

Log J-hook Vanes for flow direction & habitat

Page 80: Tools for Stream Restoration: Morphology & Structures

Log Vane •  2-4 % arm slopes

•  20-25 degree arm angles

•  Sealed with woven geotextile & backer logs

Page 81: Tools for Stream Restoration: Morphology & Structures

Log J-Hook Vane: Flow direction, bank protection, habitat

Arm slope = 1.2 / 30 = 4%; Arm angle = 25 degrees

Page 82: Tools for Stream Restoration: Morphology & Structures

Storm Flow: Flow direction + Bank protection

Page 83: Tools for Stream Restoration: Morphology & Structures

Toe Wood for bank protection, roughness, habitat

Page 84: Tools for Stream Restoration: Morphology & Structures

Toe Wood for bank protection, roughness, habitat

Page 85: Tools for Stream Restoration: Morphology & Structures

Log J-hook: Habitat enhancement

Page 86: Tools for Stream Restoration: Morphology & Structures

Log J-hook Installation

1.  Root wad 2.  Header log 3.  Backer log 4.  Chinking 5.  Geotextile

Page 87: Tools for Stream Restoration: Morphology & Structures

Log J-hook Installation

6.  Backfill gravel 7.  Wash in 8.  Boulder hook 9.  Chinking 10. Geotextile

Page 88: Tools for Stream Restoration: Morphology & Structures

Log J-hook with Toe Wood

Page 89: Tools for Stream Restoration: Morphology & Structures

Multiple Log Vanes

Saugahatchee Creek

2007

2008

Page 90: Tools for Stream Restoration: Morphology & Structures

Multiple Log Vanes

Saugahatchee Creek

2009 January

2009 July Photo Credit: Dan Ballard, Town of Auburn

Page 91: Tools for Stream Restoration: Morphology & Structures

Multiple Log Vanes: Saugahatchee Creek

Photo Credit: Dan Ballard, Town of Auburn

Page 92: Tools for Stream Restoration: Morphology & Structures

Boulder Cross Vane: Flow Concentration

Page 93: Tools for Stream Restoration: Morphology & Structures

Cross Vanes for flow direction & grade control

Page 94: Tools for Stream Restoration: Morphology & Structures

Cross Vane •  Direct flow in new channel alignment •  Grade control and scour pool •  Footer boulders & geotextile

Page 95: Tools for Stream Restoration: Morphology & Structures

Cross-Vane (Double-Drop): Flow direction straight & center

Arm Angles: 25 degrees from parallel to bank

Page 96: Tools for Stream Restoration: Morphology & Structures

Cross-Vane (Double-Drop): Limit drop over each step to 0.5 ft

Page 97: Tools for Stream Restoration: Morphology & Structures

Cross-Vane (Double-Drop): Grade control, flow direction, scour

Arm slope = 1.8 / 36 = 5%

Max drop over each step = 0.5 ft

Page 98: Tools for Stream Restoration: Morphology & Structures

Cross-Vane (Double-Drop): Grade control, flow direction, scour

Arm slope = 2.5 / 50 = 5%; Arm angles = 25 degrees

Max drop over each step = 0.5 ft

Page 99: Tools for Stream Restoration: Morphology & Structures

•  Undercut bed 2 ft and backfill with gravel, cobble, boulders, wood

•  Cut thalweg 0.5 ft deep

Cross Vane (logs embedded)

Page 100: Tools for Stream Restoration: Morphology & Structures

Multiple Cross Vanes in Straight Urban Stream

Page 101: Tools for Stream Restoration: Morphology & Structures

Double-Drop Boulder Cross Vane

Photo Credit: Darrell Westmoreland, North State Environmental, Inc.

Page 102: Tools for Stream Restoration: Morphology & Structures

Double-Drop Boulder Cross Vane

Page 103: Tools for Stream Restoration: Morphology & Structures

Offset Boulder Cross Vane at a Bridge

Page 104: Tools for Stream Restoration: Morphology & Structures

Boulder W-Vane: Bridge Pier Protection

Page 105: Tools for Stream Restoration: Morphology & Structures

Boulder Double Wing Deflector

Page 106: Tools for Stream Restoration: Morphology & Structures

Constructed Riffle

Page 107: Tools for Stream Restoration: Morphology & Structures

Stream Competence (www.epa.gov/WARSSS)

Page 108: Tools for Stream Restoration: Morphology & Structures

1st Order Streambed Transplant •  Substrate transfer from old channel to new channel

Page 109: Tools for Stream Restoration: Morphology & Structures
Page 110: Tools for Stream Restoration: Morphology & Structures

Constructed Riffle •  Undercut bed 2 ft and backfill with gravel, cobble,

boulders, wood •  Cut thalweg 0.5 ft deep

Page 111: Tools for Stream Restoration: Morphology & Structures

Constructed Riffle with Embedded Wood

Page 112: Tools for Stream Restoration: Morphology & Structures

Vanes, Toe Wood, Transplants

Page 113: Tools for Stream Restoration: Morphology & Structures

Riffles with Bouder/Log Steps

Page 114: Tools for Stream Restoration: Morphology & Structures

Step-Pool: Boulder Cascade

Page 115: Tools for Stream Restoration: Morphology & Structures

April, 2011

March, 2011

Page 116: Tools for Stream Restoration: Morphology & Structures

August, 2011 Early Succession

Forest

March, 2011 Native Riparian Plants

Page 117: Tools for Stream Restoration: Morphology & Structures

Illinois River Site 5: Tahlequah – Kaufmann Boulders & logs in new

channel

Page 118: Tools for Stream Restoration: Morphology & Structures

Step-Pool: Stormwater Conveyance Chapel Hill, NC Bolin Creek Watershed

Page 119: Tools for Stream Restoration: Morphology & Structures

Step-Pool: Stormwater Conveyance, Maryland