culvert inventory and assessment protocol 2015 field season
TRANSCRIPT
Culvert Inventory and Assessment Protocol
2015 Field Season
Conduct Field Inventory
Inventory andAssessment Process
Coarse Filters
GREEN(Passable)
RED(Impassable)
GREY(Indeterminate)
Prioritize for remediation
Further Analysis
Field Survey – Main Steps
• Navigate to predetermined road crossing using maps and/or GPS
• Perform longitudinal survey
• Complete site sketch
• Take and document photos of site
Field Equipment
$100
$450
$300
$300
$25
$15$30
$70 $200
$200
Safety• All crew members must wear a safety vest and
hardhat when performing surveys.• Slip resistant wading boots are required for all
crew members, regardless of what job you are assigned.
• Know the hazards in and around the stream channel (e.g., slick rocks, broken glass, wasp nests, snakes, etc.)
• Follow all USDA Forest Service rules and guidelines when operating FS vehicles and equipment.
Non-surveyed crossings
Natural Ford
Insufficient Upstream Habitat
No access
Bridge
Does Not Exist
Flow Condition
Isolated pools,
discontinuous flow
Dry, no flowWet, continuous flow
Pipe Shapes
• Circular
• Pipe Arch
• Open Bottom Arch
• Box
• Ford
• Vented Ford
Circular
Diameter
Circular
Pipe Arch
Rise
Pipe Arch
Span
Open Bottom Arch
Rise
Span
Open Bottom Arch
Box
Height
Width
Box
Vented Fords
• Corrugated Metal• Concrete• Plastic• Smooth Metal• Wood• Unknown
Crossing Material
Continuous Substrate
Continuous
Not continuousNot continuous
Longitudinal Profile Survey
Culvert inlet P2
Culvert outlet P4
Tailwater control P6
Deepest point within 1 foot P5
Outlet drop
Road surface P3
culvertPipe slope & slope x length
Outlet perch
Surveying the Crossing
Establish Benchmark
Surveying the Crossing
P3 Road Surface
Surveying the CrossingP2 inlet, and P4 outlet bottoms
P2 = inlet
P4 = outlet
Surveying the CrossingP5 Max Pool Depth within 1 foot of Outlet
Max Pool Depth w/in 1’
1’ Max Pool
Max Pool Depth w/in 1’ AND Max Pool Depth1’
Surveying the CrossingP5 within 1 foot of P4b when Apron Present
P4b
P5
P4bP5
P4b
P5
Surveying the CrossingP6 Tailwater Control
Tailwater Control
• Place rod at average depth of tailwater control
x
Surveying the CrossingP6 Tailwater Control
Measuring tailwater control depth
Surveying the CrossingWhere is the (P6)Tailwater Control?
Surveying the Crossing(P6) Tailwater Control
Surveying the Crossing
Closing the Survey
The survey must be closed to check for accuracy
BM
P3
1
2
BM Rod Read + 100 = Height of Instrument (HI)
HI - P3 Rod Read = Known Elevation for P3
Move Level
New P3 Rod Read
New P3 Rod Read + Known Elevation for P3= New HI
New BM Rod Read
New HI – New BM Rod Read = New Elevation
100 – New Elevation = Error (Must be within ±0.02)
P6>P2 = fully backwatered
P4-P6 = outlet drop (in)
P4-WSP5= outlet perch (in)
pipe slope (%) x pipe length (ft) = slope x length
Elevations measurements
Culvert inlet P2
Culvert outlet P4
Tailwater control P6
Water surface
Outlet drop
Road surface
culvert
Pipe slope
Outlet perch
Calculations
Incomplete Site Sketch
Complete Site Sketch
Items to include:• Flow direction• North arrow• Channel alignment• Photo location• Road features• Stream features• Level setup location• Road descriptions• Crossing features
Take Photos
Photos of the inlet and outlet
Items to capture in photos:• ID board with proper info• Entire culvert opening• Some adjacent channel• Stadia rod
Good Photos
Good Photos
Bad Photos
Things to avoid in photos:
• Blurriness
• Zoomed in too far
• Zoomed out too far
• Cannot see board
• Rod not included
• Cannot see all the pipes
• Light reflecting off the board
• Incorrectly labeled board
Special Cases
– No crossing in GPS, but you are at a crossing– Multiple pipe crossings– Fords– Vented Fords– Dry Streams– No Outlet Pool– Dry Stream and no outlet pool
Multiple Pipe Crossings
• You will still follow the single pipe crossing Forms, there will just be more than one pipe for that crossing.
• Pipes are counted from left to right when looking downstream.
Fords
• Leave unnecessary fields blank on survey form (e.g. pipe width, pipe height)
• Number of pipes for ford = 1
• Pipe number for ford = 0
Vented Fords
• Survey all the points for the pipes and all the points for the ford
• Number of pipes = pipe count + 1• Ford pipe number = 0
– Photo: number of pipes = 5– Photo: label the pipe numbers
?
14
0
23
Dry Streams
• Dry streams are surveyed in the same manner as continuous flow or discontinuous flow streams.
• Outlet drop (P4 - P6) is used in the calculations, even without water being present.
No Outlet Pool• Sometimes there is no outlet pool
• No outlet pool means no P6
– i.e. there is no tailwater control to make a pool
• Leave P6 blank, but make a comment
• We use P5 + water depth at P5 to calculate outlet perch in these situations
No Outlet Pool + Dry Stream
• Unique situation, but it happens
• Record all available points (excluding P6)
• Record 0 for water depth at P5
• Be sure to record in comments: “Dry and no outlet pool”
Final Thoughts
• Every crossing is unique, that’s why we have cameras and a comments field.
• Pay attention to detail during the entire survey process.
• Don’t cut corners to save time, it’s about quality not quantity.
• You represent CATT & VT, make sure your behavior and professional demeanor are reflective of all of us.
The End
P6>P2 = fully backwatered
P4-P6 = outlet drop (in)
P4-WSP5= outlet perch (in)
pipe slope (%) x pipe length (ft) = slope x length
Elevations measurements
Culvert inlet P2
Culvert outlet P4
Tailwater control P6
Water surface
Outlet drop
Road surface
culvert
Pipe slope
Outlet perch
Calculations
P6>P2 = fully backwatered
P4-P6 = outlet drop (in)
P4-WSP5= outlet perch (in)
pipe slope(%) x pipe length (ft) = slope x length
Elevations measurements
Culvert inlet P2
Culvert outlet P4
Tailwater control P6
Water surface
Outlet drop
Road surface
culvert
Pipe slope
Outlet perch
Calculations
P6>P2 = fully backwatered
P4-P6 = outlet drop (in)
P4-WSP5= outlet perch (in)
pipe slope(%) x pipe length (ft) = slope x length
Elevations measurements
Culvert inlet P2
Culvert outlet P4
Tailwater control P6
Water surface
Outlet drop
Road surface
culvert
Pipe slope
Outlet perch
Calculations
No Outlet Pool
• The absence of an outlet pool results in the “leap” (usually calculated as the distance between the tailwater control (P6) and the culvert outlet (P4)) being calculated by using outlet perch (water depth at P5).