2013 afs lessons learned

Restoration Lessons Learned From a Fish Hugger & River Nerd

David BidelspachJames Vincent

Restoration Lessons Learned• #1 – Develop a Process Based Restoration

• Matrix for Key Species

• #2 – Energy/Heat Dissipation• Un-uniform Energy Dissipation will limit the fishery

• #3 - Central Tendency of a River• This is not subjective; understand fluvial geomorphology

• #4 – Floodplain Interactions• Don’t let the fishery be Imparted by Channel Incision and Poor Floodplain

Function

• #5 – Regional Curves and Mini-Regional Curves• Trying to provide habitat improvements without the proper channel dimension

is like a “Love Grenade”. You are lovingly trying to help the fishery but it is just going to blow up in your face

#1 – Develop a Process Based Restoration

• Process based design is a design that is targeted to increase the function of a process to meet the goals and objectives of a project. Paraphrase from Dr. Palmer June 2nd

#2 – Uniform Energy/Heat Dissipation

• Uniform Energy Dissipation vs. Large Energy Dissipation Structures– Longitudinal Profile concavity– Profile Slope should decrease with flow– Transition between energy states or maintenance

• Pool- Pool Spacing– Existing conditions as a boundary based on reach

stability and confinement– Central tendency and effective discharge

• Width to Depth Ratio – Thermal Heat Transfer

AS-BUILT LONG PRO vs. PRE CONDITION LONG PRO

CH

WS

BKF

P1

P2

P3

P4

Existing Based on As-built

Elev

atio

n (ft

)

Distance along stream (ft)

940

942

944

946

948

950

952

954

956

958

960

962

964

966

968

970

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400

XS

5 -

AS

BU

ILT

XS

6 -

AS

BU

ILT

XS

3 -

AS

BU

ILT

XS

2 -

AS

BU

ILT

Non- Uniform Energy Dissipation

Add Water

#3 - Central Tendency of the River

• The answers are in the River• Use current technology to document existing

morphology– Scour lines– Deposition - Bar Formation– Bankfull Features when appropriate– Pool-Pool spacing– Reference Parameters and Reference Reach

Simon Channel Evolution Model

Source:

Simon, 1989, USACE 1990

MatrixChannel Incision – High WDR

- Vegetation and Sediment Transport

Channel Incision – High WDR- Vegetation and Sediment Transport

# 4 Floodplain Interactions - Incision

• Choice of Design Flow and Flow Regimes– Don’t limit the design to the Bankfull flow

• (~ 1.2yr event in NC)

– Design up to an acceptable risk level with multiple flows • (1.01 Low- Flow, 1.2yr Bankfull, 2yr, 5 yr, 25yr, 100 yr)

• Convergence and Divergence of all Design Flows– Change in velocity and sediment transport competency and capacity due to

convergence and divergence of flow could lead to critical flow and a hydraulic jump

• ( 10:1 Horizontal transition)• (100:1 vertical from the channel slope)

• Turning of Design Flows– Increase of Shear Stress based on radius of curvature is not limited to the

bankfull channel • (2* W Min radius of curvature for any design flow)

Saamis Coulee Medicine Hat , Alberta

- Choice of Design Flow and Flow Regimes

Floodplain Interactions and Function

Channel Incision – High WDR- Vegetation and Sediment Transport

# 5 Mini- Regional Curves

• A mini- regional curves within the disturbed watershed can be used as a design tool more appropriately than a standard bankfull regional curve

• A mini-regional curve based on area can be done for any project and should be to help quantify design uncertainty

• Create regional curves on bankfull, Inner-berm, TOB and other depositional features when available

• Published regional curves should be used as a comparison not as a design tool

• Discuss regional and mini-regional curves with friends

Harris County 01-07-09Regional Curve

Bankfull

y = 18.762x0.6239

R2 = 0.9738

Inner Berm

y = 8.7236x0.6359

R2 = 0.9578

ALL TOB WITH SANDY DEP

y = 54.17x0.4879

R2 = 0.8556

TOB 45% - 65% Imp

y = 68.465x0.6289

R2 = 0.9861

TOB 25% - 45%

y = 45.515x0.6292

R2 = 0.9358

TOB 10% - 25%

y = 37.299x0.6137

R2 = 0.9933

1.0

10.0

100.0

1000.0

10000.0

0.1 1.0 10.0 100.0 1000.0

Drainage Area (sqmiles)

Cros

s-AS

ectio

nal A

rea

(sqf

t)

Inner Berm Bankfull Top of Bank Original Harris Co. Data45-65 25-45 15-25 Spring Ceek Reference ReachPower (Bankfull) Power (Inner Berm) Power (Top of Bank) Power (45-65)Power (25-45) Power (15-25)

Restoration Fundamentals• The answers are in the river

• Are we fighting the central tendency?• This is not a subjective

• What is the geomorphic potential?• Design sustainability• Floodplain Interactions

• Don’t let the fishery be limited by Channel Incision and Poor Floodplain Function