LOCKED LOGS (LL). THIS METHOD IS A DAVE DERRICK DISCOVERY (DDD)

LOCKED LOGS (LL)

THIS METHOD IS A DAVE DERRICK

DISCOVERY (DDD)

The "Locked Limb/Locked Log" Concept • Consists of entire trees large or small, and/or Small

Woody Debris (SWD) consisting of limbs, limbs with leaves, sections of small tree trunks, tree tops, etc. anchored within or placed under structures, with limbs/logs protruding into deeper scoured areas to provide in-stream cover, vertical and horizontal structure, hydraulic roughness, & areas of refugia.

• Can be either hand- or machine-placed

• Locked Limbs are typically less than 2” inches in diameter, Locked Logs are greater than 2 inches in diameter

Courtesy of Ecology and Environment, Inc.

Analysis of existing downed logs in the stream system should be

undertaken, & the LOCKED LOGS placed at similar angles

(typical angles are from 15 to 35 degrees downstream relative to the bank). The root wad is positioned

upstream. Study nature!!

MILL BROOK, SALISBURY, NEW

HAMPSHIREPROJECT

CONSTRUCTED July 7-16, 2010

Trees were angled downstream 30 degrees from the bank with the root wads upstream against

the eroding bank

Road

Locked Logs

Stone is then loaded on the Locked Logs which “locks” the log in place. Best to have a root wad attached to the log which acts as

a spread anchor.

Road

Locked Logs

LOCKED LOG provides hydraulic roughness & aquatic habitat

HIGH WATER-Site #2-Looking US @ 13 Locked Logs providing chaotic structure habitat & in-stream refugia. Thalweg bubbles near inside of bend.

HIGH WATER-MILL BROOK, NH-PIX BY DAVE DERRICK 7-14-2010

Flow

Locked Logs

Ston

e to

e pr

otec

tion

Place logs on bed of stream, angle log

downstream at the appropriate angle, then place stone on the Locked Logs which “locks” the log in place. Root

wad acts as a spread anchor.

GOAL & FUNCTION-BASED DESIGN FOR RIPARIAN &

STREAM SYSTEMSTHE EIGHTEENMILE CREEK

PROJECT CONSTRUCTED AUG-SEPT 2003by Dave Derrick

EIGHTEENMILE CREEK IS A SUBURBAN,

GRAVEL-COBBLE BED, POOL-RIFFLE-POOL

REGIME STREAM IN A DEEP V-SHAPED

VALLEY

A downstream reference wood jam for Locked Limbs/Locked Logs. Always

try to imitate nature & natural functions

Pix by Derrick

Floating the “footer” log

in place

Pix by Derrick

“Footer” log in place with Locked Logs placed perpendicular & over

top of footer log.

Locked Logs now “locked” in place with stone

Pix by Derrick

Row of Locked Logs

Pix by Derrick

Locked Logs

Pix by Derrick

Locked Limbs & Locked Logs one year

later, June 24, 2004

Pix by Derrick

THE IMPORTANCE OF SMALL WOODY DEBRIS, LEAF LITTER & LEAF PACKS

• Dead things are good things, and these are typically present in nature and reference reaches, but sometimes completely forgotten during “restoration” projects

• Can be extremely important in starting the food web, for cover (horizontal and vertical structure) for juvenile fishes, and substrate for benthic macro invertebrates

• Should be added to the stream during restoration in appropriate amounts and spacing based on analysis of similar reference reaches

• After appropriate analysis, downed trees and/or brush piles might also be placed in riparian areas

BEWARE: Large debris piles at bridges or other constrictions can lead to maintenance nightmares & carbon-starved downstream reaches

Locked Logs for McKinstry Creek, Delevan, NYThis a gravel-cobble bed stream, with a constant slope of 1% in the project area, rural, first order

headwater stream, with a pool-riffle-pool regime.

McKinstry Creek, Delevan, NY

This was a complete stream and floodway realignment. Constructed

June-July 2005. The stream had been straightened prior to 1939 (probably to accommodate the

construction of Gooseneck Road)

McKinstry Creek near Delevan, NY, 5-18-2006,

flow left to right

Existing planform (red line)

In the 1939 aerial photos the stream had already been straightened & was parallel

with the road. Where had it been?? How long was it?? No one knows.

Existing planform (red line)

The stream needs to be longer and/or rougher but we are

hemmed in by the road & the hill.

Green line is toe of hill

We will have to increase the amplitude of the vertical sine wave (extreme verticality)!

Gooseneck Road

McK

instry Road

McKinstry Creek near Delevan, NY, 5-18-2006,

flow left to right

New channel planform (blue line)

The “Shadow Wall” Pool with Locked Logs and a large transplanted multi-

trunk Alder for shade

Channel dug to invert

depth, 5 ft below

surrounding land

Not as easy to build as it looks

“Shadow Wall” stones, A-axis of

stone placed perpendicular

to flow

Half-Dense Riprap with Shadow Wall Toe

Stone with Vertical

face

The toe stone is designed to cast a shadow into the

deepest section of the channel


Stone with Vertical

faceShadow area


Bottom of stone placed deeper than maximum scour in pool

Neither the shadow wall or the half-dense riprap is self-adjusting, both are foundation dependent

Stone for half-dense riprap should be

embedded 50% and cover less than 50%

of the bank area

Plantings (including vines) should be integrated into

the half-dense riprap

Locked Logs placed in 3 ft deep pool

Locked Log locked down with “Shadow Wall” stones

Hand rolling a stone to lock down a Locked Log

All aquatic habitat features are designed to be submerged during base flow conditions

Looking US at pre-dug pool with Shadow Wall & Locked Logs (everyone’s fav pool)

CASE STUDY: GROUNDBREAKING BANK PROTECTION MISSOURI RIVER @

LEWIS & CLARK REGIONAL WATER

SYSTEM, VERMILLION, SD.

MISSOURI RIVER @ LEWIS & CLARK REGIONAL WATER SYSTEM, VERMILLION,

SD.• Very large river• Congressionally designated as a Wild & Scenic

River in 1978. This is a recreational reach. • Can flood for months at a time• Ice and ice damage are issues• 5,120 ft of protection on the left descending

bank US of the Highway 19 bridge, Vermillion, SD.

• Banks 25 ft tall, very fine grained sand, almost fluff

• Pool-riffle-pool regime, slope one ft per mile

FUZZY EXTREME

LOCKED LOGCedar tree with lots of branches

Looking US. A cedar Fuzzy Extreme Locked Log

CONSTRUCTION-MISSOURI RIVER @ L & C-DERRICK-NOV 15, 2007

Looking US. Placing the Fuzzy Extreme Locked Log in trench


Looking US. Fuzzy Extreme Locked Log is locked in place with toe stone. Crest width on toe stone is 10 ft wide. 113 trees spaced 50ft apart were placed.

Trees were 65 to140 ft long, with 15 ft of trunk & the root wad buried under the stone toe. Angle downstream varied from 70 to 30 degrees.


Looking US. Smoothing choke soil on the 10 ft wide toe stone crest with the

Bobcat.

CONSTRUCTION-MISSOURI RIVER @ L & C-TERRY STOLTENOW-12/5/07

THE ENVIRONMENTAL AND HYDRAULIC ATTRIBUTES GO

HAND-IN-HAND ON THIS PROJECT

Looking US @ self-adjusting toe stone & Extreme Locked Logs, natural bank

US.


EXTREME LOCKED

LOGS WITH ICE

ICE MANAGEMENT FOR STABILIZATION/RESTORATION PROJECTS

Increase roughness of the bank and near-bank aquatic area!!!

• Ice will form first in slow water

• Ice will be thickest in the slower water

• Next the entire stream has an ice cover

• Then the spring ice-out occurs

• The thickest ice near the bank will stay put so that plants are not sheared & smaller stones are not plucked

Ice surrounding LL fends off moving ice floes. Thickness of ice shows flow velocity

differentials

CONSTRUCTION-MISSOURI RIVER @ L & C-DERRICK-DEC 11, 2007

Looking DS at ice buildup around the Locked Logs.

CONSTRUCTION-MISSOURI RIVER @ L & C-DERRICK-DEC 11, 2007

Looking DS at toe stone & Extreme Locked Logs.


THE POWER OF LOCKED LOGS ON

THE MISSOURI RIVER DURING THE GREAT

FLOOD OF 2011.

39-40 Months After Project Completion

GREAT FLOOD OF 2011 AERIAL

PHOTOGRAPHSDifferent dates

GREAT FLOOD OF 2011-Looking DS. Clearly visible foam line indicates the influence of the Locked Logs, (slower water nearer

bank). Logs are submerged at least 8 to 10 ft.

38 MONTHS LATER- MISSOURI R.@L & C-FROM TED HALL 6-29-11

40 Months After Project Completion

GREAT FLOOD OF 2011PIX TAKEN TWO FOOT

BELOW FLOOD CRESTPhotos by Derrick

JULY 30, 2011

2 FT BELOW GREAT FLOOD OF 2011 CREST-Looking @ foam line approx. 100 ft. into channel caused by the reduction in flow velocity due to the Locked Logs. Logs 8-10 ft under water.

40 MONTHS LATER- MISSOURI R.@L & C-PIX BY DERRICK 7-30-11

2 FT BELOW GREAT FLOOD OF 2011 CREST-Looking DS @ foam line delineating the outermost effect of the Locked Logs in

reducing flow velocity. Logs 8-10 ft under water.


2 FT BELOW GREAT FLOOD OF 2011 CREST-Looking DS @ debris on bank. All 4 rows of willows under water. No erosion!


HIGH-LOW LOCKED LOGS

After watching them perform during the flood, the contractor, Tom Powell, is a big

Locked Log fan, so he staggered them high & low to better slow water than if all logs were

placed at the same elevation.

Looking DS @ left bank 4.25 YEARS LATER-Looking DS @ a Locked Log (LL) high in water column. After watching them perform during the flood, the contractor staggered the LL high & low to better slow water than

if all logs were placed at the same elevation.

4.25 YEARS LATER- MISSOURI R.@L & C-FROM DERRICK 8-2-2012

Looking DS @ left bank 4.25 YEARS LATER-Looking DS @ Locked Log installed lower in the water column. High & low logs slow more water & are more

effective than all logs at the same elevation.

4.25 YEARS LATER- MISSOURI R.@L & C-FROM DERRICK 8-2-2012

This PowerPoint presentation was developed & built by Dave Derrick.

Any questions or comments, call my personal cell @ 601-218-7717, or email @ [email protected]

Enjoy the information!!

mailto:[email protected]

Documents

LOCKED LOGS (LL). THIS METHOD IS A DAVE DERRICK DISCOVERY (DDD)