Little Sackville River Digger Log Installation 2009 - The Atlantic ...

Little Sackville River Digger Log 

Installation 2009 

Prepared for the Atlantic Salmon Conservation 

Foundation 2008 Restoration Contract 

September 1 st , 2009 

Kate MacPhee, John‐William Brunner and Cyndi LeBlanc 

0 | D igger Log Installation 2009

Table of Contents 

Table of Contents ............................................................................................................................ 1 

Acknowledgements ......................................................................................................................... 2 

Introductory Information for 2009 Digger Log Installation and Maintenance ............................... 4 

Work Area 2009 ............................................................................................................................... 6 

Digger Log Schematic ...................................................................................................................... 7 

Structure Descriptions ..................................................................................................................... 8 

Electro‐Fishing Survey on Little Sackville River July 2 2009 .......................................................... 25 

Concluding Remarks ...................................................................................................................... 29 

Appendix A – Budget ..................................................................................................................... 30 

Appendix B – Press Release ........................................................................................................... 31 

Appendix C – Press Coverage ........................................................................................................ 32 


Acknowledgements 

Kate MacPhee 

I would like to thank the Sackville Rivers Association for the opportunity to work with them this 

summer. This is my first summer working with the SRA, and I have been a member/volunteer 

with the association for about a year. I graduated from Sackville High School in 2004 and I 

graduated from Dalhousie University in May 2009 with a B.Sc. in Marine Biology, and am 

interested in ecology. I am employed with the Sackville Rivers Association through the Nova 

Scotia Youth Conservation Corps. This summer my main project was to oversee the installation 

of digger logs along the Lower Little Sackville River. I have also taken part in the Sackville Rivers 

Association’s education program, salmon and trout stocking through DFO, bi‐weekly water 

quality monitoring, and volunteer cleanups. I would like to thank the Nova Scotia Youth 

Conservation Corps for the opportunity to work for the Sackville Rivers Association this summer. 

I feel as though my experience through the summer will be a great asset to me. I would love to 

find a career in fisheries or ocean management. 

Cyndi LeBlanc 

This has been my first year working with the SRA. I would like to extend sincere 

gratitude to the Sackville Rivers Association for providing me with the opportunity to explore a 

work term with them this summer. I graduated from Sackville High School in 2008 and currently 

attend Dalhousie University. My interest in environmental issues was sparked at a young age 

while participating in the Girl Guides of Canada programs. While working on our river 

restoration projects, I have gained a greater appreciation for the community that I live in and 

the individuals who contribute to it. I am extremely proud to have such a strong and active 

environmental NGO in my hometown, and I am humbled by the true dedication and passion I 

have witnessed by volunteers and employees this summer. This was the first time I have 

worked in the environmental field, and I hope to continue with the SRA as a volunteer. 

John William‐Brunner 

I am very thankful to have been employed by the SRA this summer. This is my first 

opportunity working here, and my first time living in Nova Scotia. I am from Huntsville Ontario, 

and recently graduated from the Ecosystem Management Program at Sir Sandford Fleming 

College, in Lindsay Ontario. Last summer I worked on a Northern Flying Squirrel research project 

in Fundy National Park and became very fond of the Maritimes. I have had an excellent 

experience so far this summer; it’s very satisfying to know many of the things I learned and 

practiced in college apply to the real world. It has been great being a part of the restoration and 

enhancement of a river and seeing the positive changes first hand. I am extremely thankful to 

the NSYCC for giving me, and the rest of our crew, the chance to participate in such great work. 

Thank you 

We would like to thank the Atlantic Salmon Conservation Foundation for funding the 

project and both the Nova Scotia Youth Conservation Corps and the Economic and Rural 


Development Employment Program for the opportunity to work with the Sackville Rivers 

Association for the summer. Thank you to Dave Barrett for providing us with the logs to do the 

work. Thanks to Thaumus Environmental Consultants for surveying the Lower Little Sackville 

River and mapping out the digger log locations. Also thanks to Amy Weston from Adopt‐a‐ 

Stream for helping lay out the river pattern last year. 

We would also like to thank Stephen Caines, the SRA Coordinator, for hiring us for the 

summer. It was a great pleasure to work with Stephen through the summer and he often 

helped out in the field whenever possible. We would also like to thank Colin O’Neil, the SRA 

Assistant Coordinator, for organizing the Lower Little Sackville Project. Colin was a valuable 

member of our field team, coming out in the field for most of the summer and his help was 

greatly appreciated. Also thank you to Walter N. Regan, president of the SRA, for his guidance 

and positivity. 


Introductory Information for 2009 Digger Log Installation and 

Maintenance 

This year, digger logs were installed in the Little Sackville River (LSR) between Hallmark 

Avenue and the LSR confluence with the Sackville River (Fig. 1 and Fig. 2.). A number of logs had 

been installed in the LSR years before, yet some were positioned incorrectly and needed to be 

changed. Some elements of the river have changed since the logs had been installed and a 

hydrology study has projected a different pattern for the river. This year there were seventeen 

new logs installed and twelve sites that had to be maintained from previous years. There were 

also more sites maintained that are not included in this report. The new logs were 

approximately eight inches in diameter and five meters long. Most logs were reused from 

previous years but new hardwood logs were used for the newly installed logs. 

Along this section of the LSR the desired river width is 5.4 meters. Based on this 

estimate, there was a distance of 32 meters between each log (six times the river width). In 

some instances the wetted width (distance between the beginning of the deflector and the end 

of the upstream side of the log) is less than the desired length. This arises because the river can 

be narrower than 5.4m or much wider. It has been found during previous projects that when the 

pattern is not followed the effectiveness of the logs is greatly reduced. These logs alternate 

between left and right pools, the alternating pattern is established to recreate the natural flow 

of the river. Some areas of the river were too wide to install one log and two logs were pinned 

together to cross the entire river width. In some sections of the river the water was too deep to 

install a log. These areas often already had a large pool, which we would improve by removing 

additional substrate material. 

Digger logs have been used for river restoration and to improve fish habitat in the 

Sackville River Watershed for almost twenty years. Digger logs imitate naturally fallen trees and 

create pools for fish to spawn. Deepening the area immediately following the digger log creates 

the pool, which act as areas of refuge and protection for the fish. The logs provide oxygenated 

water for the fish as well as restore the natural pattern of the river that has been lost over time. 

The logs also move substrate from the riverbed and deposit it along the shoreline. This prevents 

erosion of the riverbank and removes harmful silt from fish spawning areas. 

Digger logs are installed by pinning them to the substrate using one meter lengths of 

rebar. The logs are installed at a horizontal angle of 30° and at a vertical angle of 3° (Figure 3). 

The vertical angle is angled down towards the pool side of the log. The pool side is located on 

the upstream side of the log and the desired depth is one meter deep. These angles help 

restore the natural meander to the river. On the opposite side of the log there is a deflector 

located on the downstream side of the log. The deflector is angled perpendicular to the log and 

reaches to the bank of the river. To help stabilize the deflector from washing out, large rocks or 

logs are also placed around the outer edge, acting as a wall. The deflector is then backfilled with 

rock so it slopes of to the bank naturally. The deflector helps to narrow the river to the desired 

width and concentrates water flow to improve digging action during high water conditions. On 

the upstream side of the log a ramp is created with smaller and flat rocks. The ramp helps to 

redirect ice over the log during the winter. The ramp gently slopes up from the river bottom to 

the top of the log. Without the ramp winter ice could wash out the log. The ramp also helps 

create the digging action by forcing the water over the log. 


Table 1. Each site number with the corresponding GPS location and structure type for the Lower 

Little Sackville River. 

Site Number GPS Type of Structure 

43 44.76045°N, 63.67675°W Right digger log 

44 44.76007°N, 63.67674°W Left rock sill 

45 44.75985°N, 63.67650°W Right rock sill 


49 44.75892°N, 63.67631°W Left digger log 




53 44.75785°N, 63.67681°W No structure 




























Work Area 2009 

This year, our digger log installation and reinstallation work began in early June and continued 

until the end of July. The mapping of the new pattern was completed by Bob Rutherford, of 

Thaumus Environmental Consultants, in April 2009. 

Figure 1. Area of the Lower Little Sackville River where work was performed, including marks for 

each digger log site. 

Figure 2. Area of the Lower Little Sackville River where work was performed. 


Digger Log Schematic 

Figure 3. Digger Log Schematic 


Structure Descriptions 

Structure 43 

Location (44.76045°N, 63.67675°W) 

A log was removed from here in previous years and placed on the right bank for reuse. A right digger 

log was installed approximately 5m downstream from the previous site. A large tree was located in 

an ideal position for a deflector so the tree was used as part of the deflector. A small deflector was 

built on the right side as well to keep the bank from eroding. A line of large rocks was also placed at 

the end of the pool to keep the water from eroding the bank downstream. Upon completion the 

pool was 35cm deep and the wetted width was 5.90m. 

Structure 44 

Location (44.76007°N, 63.67674°W) 

A left rock sill was installed here in previous years. The rock sill was still intact, so we deepened the 

pool and improved the deflector. The pool was 35cm deep and the wetted width was 4.5 m. 


Structure 45 

Location (44.75985°N, 63.67650°W) 

A right rock sill was installed here in previous years. The rock sill was still intact, so we 

deepened the pool and built up the deflector. The pool may need to be maintained next year 

because most of the rocks next to the pool were small and easily transported back to the pool. 

Upon completion the pool was 38cm deep and the rock sill had a wetted width of 4.10. 

Structure 46 

Location (44.75971°N, 63.67632°W) 

A right log was installed last year; no maintenance was performed at this time. 

Structure 47 

Location (44.75951°N, 63.67609°W) 

No structure was installed here; the deep pool and large river bend did not necessitate a 

structure 


Structure 48 

Location (44.75914°N, 63.67624°W) 

A right log was installed here in previous years, consisting of two logs put together. The log was 

removed and both the horizontal and vertical angles were corrected. We performed 

maintenance and built the deflector out from its previous location to meet the newly installed 

log. The deflector was extremely large because of the length of the log. There is also a large 

rock that was in front of the pool that was unable to be moved that may need to be moved in 

years to come. Upon completion the pool was 33cm deep and the wetted width was 5.90m. 

Structure 49 

Location (44.75892°N, 63.67631°W) 

A left log was installed here in previous years. General structure maintenance was performed. 

The ramp has sustained a lot of damage and substantial improvements were made. Upon 

completion the pool was 36cm deep and the wetted width was 5.8m. 


Structure 50 

Location (44.75866°N, 63.67652°W) 

A right log was installed here in previous years; general maintenance was performed at this site. 

Upon completion the pool was 31cm deep and the wetted width was 4.7m. 

Structure 51 

Location (44.75838°N, 63.67666°W) 

A left log was installed here in previous years; general maintenance was performed. The pool 

was fairly shallow so it needed to be improved quite a bit. Upon completion the pool was 36cm 

deep and the wetted width was 4.40m. 


Structure 52 

Location (44.75785°N, 63.67679°W) 

A right log was installed here in previous years. There was a log moved up from a previous site 

approximately five meters downstream. The old deflector was still there, and we moved the 

large rocks up to the new log location. We also lined the right shore with large rocks, as there 

was a large amount of erosion. The pool was fairly shallow so it required a lot of digging. Upon 


Structure 53 

Location (44.75785°N, 63.67681°W) 

No structure was installed here. The surrounding rock was too large for a digger log to work 

effectively and there was already a pool. The large pool was dug out and a small deflector was 

built upstream to the right of the pool. Upon completion the pool was 38cm deep. 


Structure 54 

Location (44.75760°N, 63.67664°W) 

No structure was installed here. Our environmental consultant is waiting to see if the hydrology 

of the river will change once machine work is performed at the s‐turn site. 

Structure 55 

Location (44.75744°N, 63.67635°W) 



Structure 56 

Location (44.75746°N, 63.67600°W) 



Structure 57 

Location (44.75766°N, 65.67590°W) 

No structure was installed here. There are various concerns at the s‐turn. The site will be reassessed 

after machine work is performed later in 2009. 

Structure 58 

Location (44.75764°N, 63.67563°W) 

A right log was installed here. A large deflector was built where the log ended. A log may need 

to be added to the end of the log if the deflector doesn’t hold through the year. A large pool 

was filled in to become the existing ramp. Upon completion the pool was 39cm deep and the 

wetted width was 4.90m. 


Structure 59 

Location (44.75759°N, 63.67510°W) 

A left log was removed and reinstalled four meters downstream to a new location. There were 

not many large deflector rocks nearby so some were brought from surrounding areas. The 

deflector may need some further building up in later years. Upon completion the pool was 

37cm deep and the wetted width was 5.1m. 

Structure 60 

Location (44.75754°N, 63.67470°W) 

A right log was installed here in previous years, which we had to re‐align and re‐build. Large 

amounts of garbage (mattress, shopping carts, television, etc.) were removed from this site as 

well. There was no deflector at this site so we built a small one on top of the bank. Upon 



Structure 61 

Location (44.75755°N, 63.67438°W) 

There was a deep pool at this site, no structure was needed. 

Structure 62 

Location (44.75728°N, 63.67418°W) 

A right log was removed and reinstalled upstream approximately 3 meters from the original site. 

A large deflector and ramp were built. Upon completion the pool was 41cm deep and the 

wetted width was 4.9m. 


Structure 63 

Location (44.75698°N, 63.67397°W) 

A left log was installed here in previous years. A large amount of garbage was removed from 

the pool end of the log. There are a lot of trees lining the pool side of the log, which provides a 

lot of shade for the pool. To fix the vertical angle we hammered down the pool side of the log 

and elevated the deflector side of the log to the proper gradient. Upon completion the pool was 


Structure 64 

Location (44.75676°N, 63.67377°W) 

A right log was installed here in previous years. The log was maintained only. A large ramp was 

re‐built. Upon completion the pool was 53cm deep and the wetted width was 4m. 


Structure 65 

Location (44.75642°N, 63.67344°W) 

A left log was installed here in previous years. The log was raised at one end to fix the vertical 

angle. The deflector was improved, yet may need to be built up to the bank next year. Upon 


Structure 66 

Location (44.75628°N, 63.67322°W) 

A right log was installed here in previous years. Maintenance was performed here. There was 

only a small deflector at this site so we built it up as much as possible given the log length. Upon 



Structure 67 

Location (44.75635°N, 63.67277°W) 

Area was a deadwater, so no structure was installed here. 

Structure 68 

Location (44.75621°N, 63.67239°W) 

A rock sill was installed here in previous years. A left log was installed here in front of the rock 

sill. The rocks from the rock sill were removed and used for both the ramp and the deflector. 

The riverbank is very high and the deflector will need to be added to next year. Upon 



Structure 69 

Location (44.75607°N, 63.67239°W) 

A left log was uninstalled and reinstalled as a right log. The log was installed to the right of a 

very large point bar made of pebbles and sand. We had to dig into the bank a few feet to install 

the log. The water was very deep at this point, so we had to add a lot of rocks to the ramp. 

Upon completion the pool was 36cm deep and the wetted width was 3.80m. 

Structure 70 

Location (44.75586°N, 63.67216°W) 

A right log was uninstalled and reinstalled as a left log. We uninstalled two logs but only used 

one log, as the new positioning of the log didn’t require a second log. The log was left on the 

bank next to the site. Upon completion the pool was 38cm deep and the wetted width was 

4.1m. 


Structure 71 

Location (44.75572°N, 63.67177°W) 

A left log was uninstalled and reinstalled as a right log. We constructed a regular deflector as 

well as a small deflector on the right side to keep the bank from eroding. An extensive ramp 

and a pool were also installed. Upon completion the pool was 49cm deep and the wetted width 

was 4.9 m. 

Structure 72 

Location (44.7550°N, 63.67127°W) 

A right log was uninstalled and reinstalled as a left log. Upon completion the pool was 20cm 

deep and the wetted width was 5.3m. 


Structure 73 

Location (44.75508°N, 63.67074°W) 

A right log was installed here in previous years. Maintenance was performed only. Upon 


Structure 74 

Location (44.75492°N, 63.67039°W) 

A left log was installed here in previous years. The vertical angle of the log was fixed and 

maintenance was performed. Upon completion the pool was 34cm deep and the wetted width 

was 4.4m. 


Structure 75 

Location (44.75474°N, 63.67005°W) 

A right log was installed here in previous years. Two deflectors were built on each side of the 

log to stop erosion to the bank. Upon completion the pool was 45cm deep and the wetted 

width was 4.2m. 

Structure 76 

Location (44.75481°N, 63.67005°W) 

A left log was installed here in previous years. Maintenance was performed only. Upon 



Structure 77 

Location (44.75465°N, 63.66933°W) 

A right double log was installed here in previous years. The logs were removed and the vertical 

and horizontal angles were fixed. The deflector was already built around the old log so only a 

few rocks needed to be added. Upon completion the pool was 38cm deep and the wetted width 

was 5m. 

Structure 78 

Location (44.75438°N, 63.66906°W) 

A left log was installed here in previous years. The vertical angle of the log was fixed. The pool 

end was already submerged so the deflector end was raised up to create the correct angle. The 

pool was already very deep, yet the ramp required a lot of work. Upon completion the pool was 



Structure 79 

Location (44.75409°N, 63.66887°W) 

A right log was installed at this site. The log had a right pool with a left bank deflector. A small 

right bank deflector was built to keep the water from eroding the right bank. Upon completion 

the pool was 35cm deep and the wetted width was 3.65m. 


Electro-Fishing Survey on Little Sackville River July 2 2009 

Crew Leader: Colin O’Neil 

Crew: Tim Kelly, John‐William Brunner, Cyndi LeBlanc, Kate MacPhee 

Water Quality 

pH: 7.7 

Water Temperature: 19.5 

Weather: Cloudy 

Equipment: Smith‐Root Model 15 POW Electrofisher 

Voltage Setting: 300 

Mode Switches: J‐5 

Table 2. Electrofishing survey area 

Electrofishing Section Average River Width* Electrofishing Section 

Length 

Electrofishing Section 

Area 

6.34m 151.83m 962.6m 2 (9.93 Units) 

*Average width taken from 5 representative width measures over the area 

Table 3. Fish Caught by Number and Density per Unit 

Species Population Density (Units) 

Atlantic salmon 48* 4.98 

Brook trout 1* 0.10 

American eel 53 5.50 

Creek chub 57* 5.92 

White sucker 33* 3.43 

Common shiner 2* 0.21 

*Only actual number of fish caught, population projection not possible 

The electrofishing survey was performed to establish a benchmark in order to help 

determine the effectiveness of restoration activities to be performed in this section of the Little 

Sackville River. The electrofishing was performed over an area as listed in Table 2 and included 

a variety of habitat areas including pools, riffles and runs. The electrofished section was in the 

middle of the planned work area for this year, starting at the old digger log on Site 62 

(44.75728°N, 63.67418°W) and extending to 15 meters upstream of site 58 (44.757770°N, 

63.67580°W), just below the s‐turn. This area was picked as a representative sample of the 

entire 2009 work area. 

The electrofishing was performed using Zippen’s 1 removal method of population 

estimation with three sweeps. This method consists of electrofishing the sample area three 

times, counting the fish caught in each sweep then removing them from the sample area for the 

duration of the survey. 

1 Zippin, Calvin. “The Removal Method of Population Estimation.” Journal of Wildlife Management 22.1 

(1958): 82‐90 

25 | Digger Log Installation 2009

Atlantic salmon 

There were a total of 48 Atlantic salmon caught during the three sweeps. The catch 

distribution did not sufficiently follow the Zippen model projections so no population estimate 

can be performed. The only conclusion that can be arrived at is there is at least 48 Atlantic 

salmon. There are no previous comparable results to analyze this data against. 

In the Little Sackville River as a general guideline fry are below 6 cm, and 1‐year smolt 

above that. The number of Atlantic salmon measured at ½ cm intervals indicates two age 

classes, fry and 1‐year parr (see Figure 4) Elson 2 developed models for optimum Atlantic salmon 

production that give a production rate of 240 eggs per unit, 29 fry per unit and 38 parr per unit. 

There were 10 parr caught during the survey and 37 1‐year parr with one outlier at 7.5 cm. This 

gives a ratio of roughly 1:4 of fry vs. parr and a density of 1.04 parr per unit and 3.84 fry per unit. 

Using both fry and parr catch to predict egg yield (see table 4) gives us a range of 8.28 to 22.85 

eggs per unit. This gives us at the egg stage 3.45‐9.52%, at the fry stage 3.59% and finally at the 

parr stage 10.1% of the optimum Elson production levels. 

Figure 4. Number of Atlantic salmon Caught by Length 

2 Elson, P.F. “Number of salmon needed to maintain stocks.” Canadian Fish Culture 21 (1957): 19‐23 

Elson, P.F. “Atlantic salmon river smolt production and optimal spawning: an overview of natural 

production.” International Atlantic Foundation Special Publication Service 6 (1975): 96‐119 


Table 4. Actual and Projected Atlantic salmon Population Using Elson Norms 

Life Stage Elson Norm Actual Estimated Yield 

Catch 

Egg/unit 240 0 using fry catch 8.28, using parr catch 

22.85 

Fry/unit 29 1.04 using parr catch 2.76 

Parr/unit 38 3.84 using fry catch 1.36 

Creek chub 

There were a total of 57 Creek chub caught during these three sweeps. The catch 


can be performed. This was probably due to the schooling behavior of the species. The only 

conclusion that can be arrived at is there is at least 57 Creek chub. There are no previous 

comparable results to analyze this data against. 

White suckers 

There were a total of 33 White suckers caught during these three sweeps. The catch 


can be performed. This was probably due to the schooling behavior of the species. The only 

conclusion that can be arrived at is there is at least 33 White suckers present. There are no 

previous comparable results to analyze this data against. 

American eel 

There were a total of 51 American eels caught during these three sweeps. These 

numbered thirty‐four in sweep one, nine in sweep two and five in sweep three. This catch 

distribution allowed interpretation through the Zippen model (see Figure 5.) The projected 

total population was 53± 4.22 at a 95% confidence limit. This gave a per unit distribution of 5.5. 

There are no previous comparable results to analyze this data against. 

Figure 5. American eels caught During Respective Electrofishing Sweeps 


Brook trout & Common shiner 

There was only one Brook trout and two Common shiners caught in the electrofishing 

survey, the numbers were too low to be significantly analyzed. There are no previous 

comparable results to analyze this data against. 


Concluding Remarks 

Logs were set on the riverbank between sites 50 and 51 to be used in the future. Logs 

that were unused this year were left in the same area. When logs were removed from sites we 

set them aside and reused them at the same sites. 

There is one site along the Lower Little Sackville River where machine work will be 

taking place (structure 57). This work will be completed by the end of August, 2009. To keep 

the banks from eroding at these sites one channel will be blocked and the other will remain 

open. Large rocks will also be placed along the bank to prevent more erosion from occurring. 

Since the hydrology study was completed and some of the old logs were re‐aligned the 

pattern of the digger logs along the river the pattern seems to be working correctly. Most of the 

logs that were taken out and replaced were not working correctly. The total area restored is 

4844m 2 . With the changes made this summer hopefully the logs will remain working correctly 

for years to come. 

As revealed through the results of our electrofishing it is important for restoration work 

to be carried out in this area. According to Elson’s developed models for optimum Atlantic 

salmon production we are at very low levels of salmon production. As stated earlier we are at 

3.45‐9.52% of optimum levels for the egg stage, 3.59% for the fry stage and 10.1% at the parr 

stage. The Atlantic salmon is one of the main concerns for the SRA and is extremely important 

to our watershed. For us to improve the habitat and raise the levels of production for salmon 

we must continue with restoration projects along the Little Sackville River. 


Appendix A – Budget 

Financial Report 

Expenditure/Component Cost Breakdown Contributor 

e.g. Time, unit costs, etc. 

Materials & Equipment 

Other Costs 

Labour 

Projected 

Cost 

Expenditure 

Digger logs with delivery Barrett Lumber $500 (in‐kind) $500 (in‐kind) 

Hand Tools/waders HRM Grant $800 $800 

Safety Equipment HRM Grant $200 $200 

Mileage ASCF $500 $500 

Crew ‐ 900 hours 

Project Coordinator ‐ 

SRA, NSYCC, 

ASCF 

$9,000, $2,000, $9,000, 

$3,000 $3,000 

$7,000, 

$6,500 $7,000, $6,500 

SRA, ASCF 

675 Hours 

SRA Volunteers ‐ 50 

Hours SRA $750 (in‐kind) $750 (in‐kind) 

River Consultant HRM Grant $1,000 $1,000 

Contingency SRA $2,925 $425 

Chainsaw $500 

Total (Full) $32,1 75 $32,175 

Total requested from the ASCF $10,000 $10,000 

Percentage of funding 31% 31% 


Appendix B – Press Release 


Appendix C – Press Coverage

Little Sackville River Digger Log Installation 2009 - The Atlantic ...

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