The Effects of Roads on the Post-Harvest Condition of Streams,
Riparian Areas, and Fish Habitats in British Columbia 1996 – 2010
Peter J. Tschaplinski
Ministry of Environment
Riparian Management
Evaluation Question
Are riparian forestry and range practices
effective in maintaining the structural
integrity and functions of stream ecosystems
and other aquatic resource features over
both short and long terms?
Stream-Riparian Indicators
1. Channel bed disturbance
2. Channel bank disturbance
3. LWD characteristics
9. Aquatic invertebrate
diversity
10. Windthrow frequency
4. Channel morphology
11. Riparian soil disturbance/
bare ground
5. Aquatic connectivity
12. LWD supply/root network
6. Fish cover diversity
13. Shade & microclimate
7. Moss abundance &
condition
14. Disturbance-increasers/
noxious weeds/invasive
plants
8. Fine sediments
15. Vegetation form, vigour,
& structure
Evaluation Approach
• Assess physical and biological conditions in streams and their
riparian areas with RSM checklist covering
15 indicator-questions
• Site assessments vary, based on stream morphology and fish
use
• 114–120 measurements, estimates, and observations are
required to complete a stream-riparian assessment based on
38–60 specific indicators
• Each main question answered “Yes = OK” or “No = problem”
• Roll-up score = overall site condition
Roll-up Scoring System
Number of “No” Indicators out of 15:
1. Properly Functioning Condition
0 - 2 No’s
2. Properly Functioning, with Limited
Impacts (= old “at Risk”)
3 - 4 No’s
3. Properly Functioning, with Impacts
(intermediate = old “at High Risk”)
5 - 6 No’s
4. Not Properly Functioning
> 6 No’s
2005-2011 Provincial Riparian-Stream Sample
Harvest
Years
S1
S2
S3
S4
S5
S6
Total
FP Code
(1997-2003)
3
57
233 215
64
521
1093
Transition
(2004-2006)
5
39
118
95
47
303
607
FRPA
(2007-2010)
0
11
46
33
22
104
216
ALL
8
107 397 343 133 928 1916
Provincial RSM Summary of Post-harvest Stream-Riparian
Condition Assessments, 2005 – 2011
800
Number of Streams
700
Sample = 1,916
722
600
563
500
400
393
300
238
200
100
0
38 %
29 %
21 %
Properly Functioning Properly Functioning, Properly Functioning,
Condition
Limited Impacts
with Impacts
12 %
Not Properly
Functioning
Overall Stream/Riparian Condition by Stream Class, 2005 – 2011
1000
Province, 2005-2011 Survey Years (n = 1,916)
900
Properly Functioning Condition
800
Properly Functioning, Limited Impacts
Properly Functioning, with Impacts
Number of Streams
700
Not Properly Functioning
600
500
400
300
200
100
0
S1
S2
S3
S4
Stream Class
S5
S6
Comparison of Post-Harvest Outcomes for BC Streams
Pre-Code vs. Post 1995
Pre-Code
Early FPC Era
(FP Board audit)
FREP
2005–2011
Riparian
Class
Percentage equivalent
to FREP NPF
Percentage equivalent
to FREP NPF
S1
5
0
0
S2
20
0.6
0.9
S3
41
4.4
5.0
S4
60
9.4
12.0
S5
45
3.3
7.5
S6
76
20.2
17.9
Percentage NPF
Trends in Post-Harvest Outcomes for BC Streams:
FP Code, Transition, and FRPA Eras
FREP Monitoring by HARVEST ERA
FP Code Era
1997–2003
Transition Era
2004–2006
FRPA Era
2007–2010
Riparian
Class
n = 841
n = 607
n = 216
Percentage NPF
Percentage NPF
Percentage NPF
S1
0
0
0
S2
2.0
0
0
S3
6.1
5.9
2.2
S4
9.9
12.6
15.2
S5
7.3
4.2
18.1
S6
17.9
16.5
18.3
Overall Results by Main Indicator-Question
Percentage of Streams
0%
20%
40%
60%
80%
100%
Channel bed disturbance (Q1)
Channel bank disturbance (Q2)
Channel LWD characteristics (Q3)
Channel morphology (Q4)
Aquatic connectivity (Q5)
Fish cover diversity (Q6)
Moss abundance & condition (Q7)
Fine sediments (Q8)
Aquatic invertebrate diversity (Q9)
Windthrow frequency (Q10)
Riparian soil disturbance/bare ground (Q11)
LWD supply/root network (Q12)
Shade and microclimate (Q13)
Disturbance-increaser plants (Q14)
Vegetation form, vigour & structure (Q15)
Yes = Not affected
No = Affected (non-forestry-related causes)
No = Affected (forestry-related impacts)
NA
Overall Sources of Impact for Affected Streams
Coast
Area
Northern
Interior
Area
Southern
Interior
Area
ALL
81
62
65
68
Low RMA Tree Retention
59
43
44
48
Windthrow
23
33
38
32
Falling and Yarding
53
20
23
30
Fire, Beetle Infestation
17
30
40
30
Machine disturbance:
Harvesting
20
23
34
26
<1
3
24
9
Major Impact Factor
Roads
(sediment
generation and transport)
(includes logging in-stream slash)
(non-forestry related)
Livestock Trampling
Sediment from Road Surfaces and Ditches
600
Number of streams
Affected
500
Not affected
Frequency of Observed
Impacts from
Road-Related Sources
400
300
200
100
0
S1
S2
S3
S4
S5
S6
Stream Class
Perched or Blocked Culvert
600
Road Crossing Leaks Fines into Stream
500
600
Not affected
Affected
Number of streams
Number of streams
Affected
400
300
200
100
500
Not affected
400
300
200
100
0
S1
S2
S3
S4
Stream Class
S5
S6
0
S1
S2
S3
S4
Stream Class
S5
S6
Frequency of Observed Impacts on Sediment/Debris from Non-Road Sources
Windthrow
Machine Disturbance in RMA During Harvest
600
600
Affected
500
Number of streams
Number of streams
Affected
Not affected
400
300
200
100
500
Not affected
400
300
200
100
0
0
S1
S2
S3
S4
S5
S1
S6
S2
S3
S4
S5
S6
Stream Class
Stream Class
Hillslope Failure
Trampling (livestock, wildlife)
600
600
Affected
Affected
Number of streams
Number of streams
500
Not affected
400
300
200
100
0
500
Not affected
400
300
200
100
0
S1
S2
S3
S4
Stream Class
S5
S6
S1
S2
S3
S4
Stream Class
S5
S6
Province-wide Riparian Retention Levels by Stream Class
Buffer Width (m) = Mean Distance from Streambank
to Beginning of Tree Harvest (Harvest Edge)
Percentage
Stream of Streams
Class
Buffered
Mean
 Standard Error
Sample (n)
S1
100
67
16.9
5
S2
100
42
2.5
72
S3
100
32
1.4
211
S4
78
17
1.4
179
S5
84
28
4.5
76
S6
56
11
1.0
516
ALL
74
20
0.8
1,059
Functional Outcomes for Streams with Full Retention vs.
Understory/Small Vegetation Within First 10 m of the RMA
Percent of Streams
Fish Bearing with
Riparian Reserves
(Class S1, S2, S3)
Classes S4, S5, & S6
with Overstory and
Understory Retention
Classes S4, S5, & S6
with Mainly
Understory Retention
PFC
51
52
22
PFC-L
31
29
30
PFC-I
13
14
28
NPF
5
5
20
Functioning
Condition
Key Factors Affecting Management Outcomes
for Stream-Riparian Systems
1. Amount of road-related sediment found at stream crossings
(all stream classes)
• Management of fine sediments remains a concern in spite of
improvements
• 83 % of non-fish-bearing class S6 headwater streams were affected
by fine sediments in the FP Code harvest years (1997 – 2003)
• This has decreased to 60 % of class S6s during the FRPA years
2. Levels of riparian tree retention for many small streams
(classes S4, S5, S6)
• Functional outcomes or “health” of small streams with buffers 10 m
wide are equivalent to larger fish-bearing streams with riparian
reserves 20 - 50 m wide
• Nearly 20 % of class S4s and 45% of S6s are without treed buffers
ADM Recommendations for Improved Practices Outcomes
1. Establish full wind-firm buffers 10 m wide on all class S4 fish-bearing streams
and PERENNIAL non-fish-bearing class S5s and S6s that deliver water, alluvial
sediments, nutrients, organic materials, and invertebrates to fish-bearing
habitats and (or) drinking water sources
•
Can be achieved without increasing overall retention levels in a landscape by redistributing current levels of riparian retention for small streams to priority reaches
2. Retain, at minimum, all non-merchantable trees, understory trees, smaller
vegetation and as many wind-firm trees as possible within the first 10 m of the
RMA for all other S5s and S6s (e.g., INTERMITTENT and EPHEMERAL streams
with low transport capability) directly connected to fish-bearing areas and (or)
drinking water sources
3. Limit fine sediments input from road crossings and riparian practices
•
Follow well-established best management practices concerning fine sediment
delivery to streams and stream crossings.
•
Forest Road Engineering Guidebook; Erosion and Sediment Control Practices for
Forest Roads and Stream Crossings; and the Fish-stream Crossing Guidebook,
Revised Edition, September 2012