3 Methods

Assessment methods for monitoring are considered preliminary and subject to revision over time. Assessment methodologies included fish passage assessments (MoE 2011a), rapid habitat assessments (Resources Inventory Committee 2001) and data gathering related to a suite of custom monitoring metrics which include some paramaters adapted from Forest Investment Account (2003).

3.1 Fish Passage Assessments

In the field, crossings prioritized for follow-up were first assessed for fish passage following the procedures outlined in “Field Assessment for Determining Fish Passage Status of Closed Bottomed Structures” (MoE 2011a). Crossings surveyed included closed bottom structures (CBS), open bottom structures (OBS) and crossings considered “other” (i.e. fords). Photos were taken at surveyed crossings and when possible included images of the road, crossing inlet, crossing outlet, crossing barrel, channel downstream and channel upstream of the crossing and any other relevant features. The following information was recorded for all surveyed crossings: date of inspection, crossing reference, crew member initials, Universal Transverse Mercator (UTM) coordinates, stream name, road name and kilometer, road tenure information, crossing type, crossing subtype, culvert diameter or span for OBS, culvert length or width for OBS. A more detailed “full assessment” was completed for all closed bottom structures and included the following parameters: presence/absence of continuous culvert embedment (yes/no), average depth of embedment, whether or not the culvert bed resembled the native stream bed, presence of and percentage backwatering, fill depth, outlet drop, outlet pool depth, inlet drop, culvert slope, average downstream channel width, stream slope, presence/absence of beaver activity, presence/absence of fish at time of survey, type of valley fill, and a habitat value rating. Habitat value ratings were based on channel morphology, flow characteristics (perennial, intermittent, ephemeral), fish migration patterns, the presence/absence of deep pools, un-embedded boulders, substrate, woody debris, undercut banks, aquatic vegetation and overhanging riparian vegetation (Table 3.1). For crossings determined to be potential barriers or barriers based on the data (see Barrier Scoring), a culvert fix and recommended diameter/span was proposed.


fpr::fpr_table_habvalue %>% 
  knitr::kable(caption = 'Habitat value criteria (Fish Passage Technical Working Group, 2011).', booktabs = T) %>% 
    kableExtra::column_spec(column = 1, width_min = '1.5in') %>% 
    kableExtra::kable_styling(c("condensed"), full_width = T, font_size = font_set)
Table 3.1: Table 3.2: Habitat value criteria (Fish Passage Technical Working Group, 2011).
Habitat Value Fish Habitat Criteria
High The presence of high value spawning or rearing habitat (e.g., locations with abundance of suitably sized gravels, deep pools, undercut banks, or stable debris) which are critical to the fish population.
Medium Important migration corridor. Presence of suitable spawning habitat. Habitat with moderate rearing potential for the fish species present.
Low No suitable spawning habitat, and habitat with low rearing potential (e.g., locations without deep pools, undercut banks, or stable debris, and with little or no suitably sized spawning gravels for the fish species present).


3.1.1 Barrier Scoring

Fish passage potential was determined for each stream crossing identified as a closed bottom structure as per MoE (2011a). The combined scores from five criteria: depth and degree to which the structure is embedded, outlet drop, stream width ratio, culvert slope, and culvert length were used to screen whether each culvert was a likely barrier to some fish species and life stages (Table 3.3, Table 3.4. These criteria were developed based on data obtained from various studies and reflect an estimation for the passage of a juvenile salmon or small resident rainbow trout (Clarkin et al. 2005 ; Bell 1991; Thompson 2013).


tab <- as_tibble(t(fpr_table_barrier_scoring)) %>% 
  mutate(V4 = names(fpr_table_barrier_scoring)) %>% 
  select(V4, everything()) %>% 
  janitor::row_to_names(1) %>%  ##turn the table sideways
  mutate(Risk = case_when(Risk == 'Value' ~ '  Value',
                          T ~ Risk))

tab %>% 
  fpr::fpr_kable(caption_text = 'Fish Barrier Risk Assessment (MoE 2011).', scroll = F)
Table 3.3: Fish Barrier Risk Assessment (MoE 2011).
Risk LOW MOD HIGH
Embedded >30cm or >20% of diameter and continuous <30cm or 20% of diameter but continuous No embedment or discontinuous
Value 0 5 10
Outlet Drop (cm) <15 15-30 >30
Value 0 5 10
SWR <1.0 1.0-1.3 >1.3
Value 0 3 6
Slope (%) <1 1-3 >3
Value 0 5 10
Length (m) <15 15-30 >30
Value 0 3 6 


fpr::fpr_table_barrier_result %>% 
  fpr::fpr_kable(caption_text = 'Fish Barrier Scoring Results (MoE 2011).', scroll = F)
Table 3.4: Fish Barrier Scoring Results (MoE 2011).
Cumlative Score Result
0-14 passable
15-19 potential barrier
>20 barrier


3.2 Habitat Assessments

Habitat was assessed rapidly according to Resources Inventory Committee (2001) with characteristics documented included channel morphology, flow characteristics (perennial, intermittent, ephemeral), the presence/absence of deep pools, substrate, woody debris, undercut banks, aquatic vegetation and overhanging riparian vegetation. A key goal of the assessments was to gather stream width information upstream and downstream of the stream crossing structures to provide information regarding stream channel constriction through road/stream crossing structures as this can hinder upstream fish migration. To standardize data collected and facilitate submission of the data to provincial databases, information was collected on “Site Cards”. Additional habitat characteristics recorded included channel widths, wetted widths, residual pool depths, gradients, bankfull depths, stage, temperature, conductivity, pH, cover by type, substrate and channel morphology (among others). When possible, the crew surveyed downstream of the crossing to the point where fish presence had been previously confirmed and upstream to a minimum distance of 600m. Any potential obstacles to fish passage were inventoried with photos, physical descriptions and locations recorded on site cards. Surveyed routes were recorded with time-signatures on handheld GPS units.

3.3 Monitoring Metrics

Custom monitoring metrics were adapted from forestinvestmentaccount2003 (Table 4.2).

readr::read_csv('data/form_monitoring_desc.csv') %>% 
 mutate(Parameter = stringr::str_to_title(Parameter)) %>% 
  mutate(Parameter = case_when( Parameter == "Uav_flight" ~ "UAV Flight",
                                T ~ Parameter)) %>% 
  fpr::fpr_kable(scroll = F,
                 caption_text = 'Description of monitoring metrics used for effectiveness monitoring.')
Table 3.5: Description of monitoring metrics used for effectiveness monitoring.
Parameter Description
Dewatering Have the remediation works led to dewatering of the channel due to substrate aggradation or other factors?
Velocity Are flow velocities similar to those within the natural channel? Are they expected to exceed swim speeds of particular fish species/life stages of interest?
Constriction Have the remediation works led to constriction of the channel. Compare channel width underneath structure and within construction footprint to average channel widths upstream and downstream?
Substrate Is the substrate within/under and adjacent to the remediated structure generally equivalent to that found upstream and downstream where natural channel conditions exist?
Riparian What is the condition of the riparian area within the construction footprint?
UAV Flight Was a flight conducted with unmmanned aerial vehicle to document conditions at time of monitoring?
Flow_depth What are the flow depths at the time of assessment within project footprint. Are depths expected to be sufficient to facilitat upstream passage for specific species/life stages of interest?
Stability Does the structure appear to be stable or is there evidence of erosion/shifting?
Revegetation How were riparian areas rehabillitated and are they improving fish habitat value?
Cover Is cover available for fish within the construction footprint in the form of overhanging vegetation, large/small woody debris, boulders, undercut banks, etc?
Maintenance If required, provide maintenance recommendations.
Recommendations General recommendations for follow up. Could include revegetation, addition of substrate, fish sampling, etc.

3.4 Reporting

Reporting was generated with bookdown (Xie 2016) from Rmarkdown (Allaire et al. 2024) with primarily R (R Core Team 2022) and SQL scripts. The R package fpr contains many specialized custom functions related to the work (Irvine 2023). In addition to numerous spatial layers sourced through the BC Data Catalogue then stored and queried in a local postgresql and sqlite databases data inputs for this project include:


Version changes are tracked here and issues/planned enhancements tracked here.