LOCKED LOGS (LL) & Locked Limbs (LL)

1. LOCKED LOGS (LL) & Locked Limbs (LL) By Dave Derrick, Potomologist & VP, River Research & Design, Inc.

2. THIS METHOD IS A DAVE DERRICK DISCOVERY (DDD)

3. 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

4. The "Locked Limb/Locked Log" Concept • When walking your streams look at how trees are undercut, fall in, and with the heavy root wad and soil within the root wad, how the ultimate alignment of the tree reposes in the stream due to stream flow forces. Almost all (>90%) will be angled downstream to some degree, and some trees might be almost parallel to flow. A number of factors will enter into the final tree resting angle. See if you can start to pick up some patterns in your area. Angles are very different in large rivers with large wood, compared to small trees in smaller streams.

5. Courtesy of Ecology and Environment, Inc.

6. 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!!

7. PRE-PROJECT-Looking DS @ hydraulically undercut trees all at the same angle relative to the bank. There is usually a range of angles in the same stream. Measure these patterns & use the range of angles in your design. PRE-PROJECT-SKUNK R.-AMES, IOWA-DERRICK 3-5-2014

8. MILL BROOK, SALISBURY, NEW HAMPSHIREPROJECT CONSTRUCTED July 7-16, 2010

9. Locked Logs Road Trees were angled downstream 30 degrees from the bank with the root wads upstream against the eroding bank

10. Locked Logs Road 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. LOCKED LOG provides hydraulic roughness & aquatic habitat

11. 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

12. Locked Logs 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. Flow Stone toe protection

13. GOAL & FUNCTION-BASED DESIGN FOR RIPARIAN & STREAM SYSTEMSTHE EIGHTEENMILE CREEK PROJECT CONSTRUCTED AUG-SEPT 2003by Dave Derrick

14. EIGHTEENMILE CREEK IS A SUBURBAN, GRAVEL-COBBLE BED, POOL-RIFFLE-POOL REGIME STREAM IN A DEEP V-SHAPED VALLEY

15. A downstream reference wood jam for Locked Limbs/Locked Logs. Always try to imitate nature & natural functions Pix by Derrick

16. Floating the “footer” log in place

17. Pix by Derrick “Footer” log in place with Locked Logs placed perpendicular & over top of footer log.

18. Locked Logs now “locked” in place with stone Pix by Derrick

19. Pix by Derrick Row of Locked Logs

20. Pix by Derrick Locked Logs

21. Pix by Derrick Locked Limbs & Locked Logs one year later, June 24, 2004

22. 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

23. 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.

24. McKinstry Creek, Delevan, NYThis 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)

25. McKinstry Creek near Delevan, NY, 5-18-2006, flow left to right Existing planform (red line)

26. 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)

27. 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 Gooseneck Road McKinstry Road We will have to increase the amplitude of the vertical sine wave (extreme verticality)!

28. McKinstry Creek near Delevan, NY, 5-18-2006, flow left to right New channel planform (blue line)

29. The “Shadow Wall” Pool with Locked Logs and a large transplanted multi-trunk Alder for shade

30. Channel dug to invert depth, 5 ft below surrounding land

31. Not as easy to build as it looks

32. “Shadow Wall” stones, A-axis of stone placed perpendicular to flow

33. Half-Dense Riprap with Shadow Wall Toe The toe stone is designed to cast a shadow into the deepest section of the channel Stone with Vertical face

34. Half-Dense Riprap with Shadow Wall Toe Stone with Vertical face Shadow area

35. Half-Dense Riprap with Shadow Wall Toe Plantings (including vines) should be integrated into the half-dense riprap 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 Bottom of stone placed deeper than maximum scour in pool

36. Locked Logs placed in 3 ft deep pool

37. Locked Log locked down with “Shadow Wall” stones

38. Hand rolling a stone to lock down a Locked Log

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

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

41. CASE STUDY:GROUNDBREAKING BANK PROTECTION MISSOURI RIVER @ LEWIS & CLARK REGIONAL WATER SYSTEM, VERMILLION, SD.

42. 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

43. FUZZY EXTREME LOCKED LOGCedar tree with lots of branches

44. Looking US. A cedar Fuzzy Extreme Locked Log CONSTRUCTION-MISSOURI RIVER @ L & C-DERRICK-NOV 15, 2007

45. Looking US. Placing the Fuzzy Extreme Locked Log in trench CONSTRUCTION-MISSOURI RIVER @ L & C-DERRICK-NOV 15, 2007

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

47. 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

48. THE ENVIRONMENTAL AND HYDRAULIC ATTRIBUTES GO HAND-IN-HAND ON THIS PROJECT

49. Looking US @ self-adjusting toe stone & Extreme Locked Logs, natural bank US. CONSTRUCTION-MISSOURI RIVER @ L & C-DERRICK-NOV 15, 2007

50. EXTREME LOCKED LOGSWITH ICE