WFLHD, Fish Passage Through Steep Gradient Culverts, Definitions

Location: Home > Fish Passage Culverts > Definitions

Related Links

Acronym List

Site Map

Definitions

Culvert Location

Identification: Name or identifier of installed culvert.
Road: Name of road culvert is located.
Mile Post: Mile post of road at culvert location.
Stream Name: Name of stream culvert is installed.
Latitude: Latitude of culvert location in decimal degrees (WGS84 datum).
Longitude: Longitude of culvert location in decimal degrees (WGS84 datum).
Elevation: Elevation of culvert location in feet (WGS84 datum).
Forest/Park: Name of county, state, or national forest or park where culvert is installed.

Data Collection

Collected by: Name of person, agency, organization, or company collecting the data.
Phone: Telephone number of person, agency, organization, or company collecting the data.
Email: Email of the person, agency, organization, or company collecting the data.

Culvert Information

Culvert Type: Material and structure shape of culvert. Choices are corrugated metal round pipe, corrugated metal arch pipe, structural plate round pipe, structural plate arch pipe, open-bottom arch or box, or concrete box.
Culvert Slope: Slope in percent along longitudinal axis of culvert invert.
Span: Maximum span of culvert in inches.
Rise: Maximum rise of culvert in inches.
Length: Length of culvert in feet.
Span/Stream Width: Ratio of culvert span to typical bankfull channel width.
Countersunk Inlet: Depth in inches the inlet invert is countersunk below the top of the streambed profile.
Countersunk Outlet: Depth in inches the outlet invert is countersunk below the top of the streambed profile.
Outlet Control: Type of stream gradient or hydraulic backwater control installed at the outlet. Choices are none, log sill, stone weir, root wad, boulder cluster, or other.
Year Installed: Year culvert installation was completed (numeric Year).
Cost: Construction cost of fish passage culvert, excluding flow diversion, sediment control, and erosion control.

Culvert Interior Treatment

Key Design Feature: Key features create diversity in flow velocity, depth, and energy dissipation patterns, and are essential for fish passage. Choices are randomly placed stone without sediment retention sills (SRS), randomly placed stone with SRS, constructed channel features without SRS, constructed channel features with SRS, or fishways.
Manning's n: Roughness coefficient used in hydraulic analysis.
Fish Passage Design Reference: Reference or approach used for fish passage design.
Bed Stability Analysis Method: Method used to evaluate stream bed stability and design streambed material gradation. Choices are none, match observed streambed material gradation, Bathurst, Shields, or other.
Streambed Material
Streambed Material: Sediment (silt, sand, gravel, cobble, boulder) placed in the culvert as substrate material and roughness or habitat features.
Type: Type of sediment or stone material. Choices are none, imported, or conserved.
Shape: Shape of sediment or stone material. Choices are angular, sub-angular, sub-rounded, or rounded.
Bed Slope: Average slope in percent of steam bed profile along longitudinal axis of culvert.
Percent Silt/Clay: Percentage of silt and clay sized material used in the streambed material mix.
D15: D15 is the median diameter in millimeters of streambed material for which 15 percent of the particles are smaller.
D50: D50 is the median diameter in millimeters of streambed material for which 50 percent of the particles are smaller.
D85: D85 is the median diameter in millimeters of streambed material for which 85 percent of the particles are smaller.
D100: D100 is the median diameter in millimeters of streambed material for which 100 percent of the particles are smaller.
Stone Roughness Features
Stone Roughness Features: Key stone features that create diversity in flow velocity, depth, and energy dissipation patterns, designed to be less mobile than the streambed material, and are essential for fish passage.
D50: D50 is the median diameter in inches of stone making up the key stone roughness features.
Shape: Shape of stone making up the key stone roughness features.
Percent of Fill: Percentage of total Streambed Material culvert fill volume occupied by stone roughness features.
Placement Pattern: Pattern of stone roughness feature placement inside culvert. Choices are none, random, clusters, transverse ribs, or along culvert wall.
Spacing: Average spacing in feet of stone roughness features inside culvert.
Step Height: Average vertical elevation difference in feet between stone roughness features s (i.e., height difference between ribs or clusters).
Sediment Retention Sills/Baffles (SRS)
Type: Type of sediment retention sills or baffles placed inside culvert. Choice are none, welded, bolted, frame, cast-in-place.
Spacing: Average spacing in feet of sediment retention sills or baffles placed inside culvert.
Step Height: Average vertical elevation difference in feet between tops of sediment retention sills or baffles placed inside culvert.
Shape: Shape of sediment retention sills or baffles placed inside culvert. Choices are none, horizontal, v-shaped, notched, slotted, angled, vertical along wall, or other.
Low Point Location: Location of low point in sediment retention sills or baffles placed inside culvert. Choices are none, side, center, staggered.
Low Point Height Above Invert: Height in inches between spillway low point of the sediment retention sills or baffles and the culvert invert.
Notch Depth: Depth in inches of notch in the sediment retention sills or baffles.
Notch Width: Width in inches of low flow notch. Input 0 for V-shaped sills that extend entire width of culvert.
Depth Buried: Depth in inches the sediment retention sills or baffles are buried by streambed material.
Bankline Features
Originally Constructed: Indicate yes or no if bankline features were originally constructed.
Present Shape: Indicate observed bankline feature condition. Choices are absent, well defined, or poorly defined.
Material: Indicate dominant material comprising the bankline features. Choices are none, >24-inch D50 stone, 18 to 24-inch D50 stone, 10 to 18-inch D50 stone, or gravel and cobbles.
Gradation: Indicate if bankline material is well graded or poorly graded.

Culvert Performance

Species: Species culvert design must provide passage. Choices are steelhead, salmon, trout, or all aquatic species, or other.
Age: Age class of species culvert design must provide passage. Choices are juvenile, adult, or both.
Passage Rating: Qualified description of passage performance. Choices are 0 - Unknown, 1 - none of the time, 2 - correctable leap at outlet restricts or prevents passage, 3 - expected for most normal fish migration period flow conditions, but not for low flow conditions, 4 - expected for most normal fish migration period low and normal flow conditions, or 5 - expected for all fish migration period low and normal flow conditions. Performance may be based on visual evaluation of flow velocity distribution patterns, measured flow velocities, or biological surveys.
Performance Basis: Basis for performance analysis. Choices are none, visual evaluation of flow velocity distribution patterns, measured flow velocities, observed fish migration, fish dye and capture, or biological surveys.
Performance Reviews Completed: Check all completed inspection and monitoring activities. Post-construction inspection is done immediately following construction; it verifies culvert was installed and functioning consistent with design intent. One-year follow-up inspection is done after culvert has been operating for one year; it verifies culvert is functioning consistent with design intent and notes evolving morphological trends. Multi-year follow-up inspection is done after culvert has been operating for more than one year; it verifies culvert is functioning consistent with design intent and notes evolving morphological trends. Biological monitoring is done after culvert has been operating for at least one year; it verifies through observed fish migration, fish dye and capture, or biological surveys that culvert is functioning consistent with design intent.
Observed Performance Issues: Check all observed performance issues.
Record Drawings: Note if record drawings of installed culvert are available, not available, or were obtained and included in the database.

Stream Information

Stream Name: Name of stream culvert is installed.
Morphology
QFish Discharge: Flow rate to the culvert in cubic feet per second (cfs) used as the fish passage design flow.
2-year Discharge: Flow rate to the culvert in cubic feet per second (cfs) corresponding to a 2-year discharge event.
50-year Discharge: Flow rate to the culvert in cubic feet per second (cfs) corresponding to a 50-year discharge event.
100-year Discharge: Flow rate to the culvert in cubic feet per second (cfs) corresponding to a 100-year discharge event.
Discharge
Bankfull Channel: Channel flowing at channel capacity and conveying the bankfull discharge. Delineated by the highest water level that has been maintained for a sufficient period of time to leave evidence on the landscape, such as the point where the natural vegetation changes from predominantly aquatic to predominantly terrestrial or the point at which the clearly scoured substrate of the stream ends and terrestrial vegetation begins.
Bankfull Channel Depth (BCD): Median depth in feet of Typical Bankfull Channel.
Manning's n: Roughness coefficient used in hydraulic analysis of stream.
Average Upstream Gradient (AUG): Average water surface slope in percent within 200 feet upstream of culvert crossing. Note gradient immediately upstream of culvert that is different from the downstream gradient indicating possible morphological instability.
Average Downstream Gradient (ADG): Average water surface slope in percent within 200 feet downstream of culvert crossing.
Typical Bankfull Channel Width (TBCW): Top width of typical Bankfull Channel in feet observed within 200 feet downstream and 100 feet upstream of culvert crossing.
Typical Bankfull Channel Reach Length (TBCL): Length of Typical Bankfull Channel reach in feet.
Flood-prone Width (FPW): Top width in feet of waterway capable of conveying the 50-year discharge, approximately equal to twice the Bankfull Channel Depth.
Flood-prone Depth (FPD): Median depth in feet of waterway capable of conveying the 50-year discharge, approximately equal to twice the Bankfull Channel Depth.
Dominant Downstream Morphology: Dominant stream morphology downstream of culvert crossing. Choices are riffle-pool, step-pool, rapid, or cascade.
Step Spacing: Spacing in feet of drop forming structures.
Step Height: Elevation difference in feet between tops of drop forming structures.
Pool Depth: Median depth in feet of pools.
Dominant Morphological Control: Dominate control on stream morphology. Choices are none, armored bed, bedrock, boulder lag deposits, large woody debris, or colluvium.
Downstream Stability: Current stream profile adjustment trends downstream of culvert crossing. Choices are degrading, stable, or aggrading.
Upstream Stability: Current stream profile adjustment trends upstream of culvert crossing. Choices are degrading, stable, or aggrading.
Streambed Material
Streambed Material: Predominant substrate sediment and stone roughness or habitat features (silt, sand, gravel, cobble, boulder).
D15: D15 is the median diameter in millimeters of streambed material for which 15 percent of the particles are smaller.
D50: D50 is the median diameter in millimeters of streambed material for which 50 percent of the particles are smaller.
D85: D85 is the median diameter in millimeters of streambed material for which 85 percent of the particles are smaller.
D100: D100 is the median diameter in millimeters of streambed material for which 100 percent of the particles are smaller.
Gradation Method: Method used for determing streambed material gradation. Choices are none, visual estimate, Wolman Peble Count, or sieve analysis.
Shape: Shape of streambed material. Choices are angular, sub angular, rounded, or sub rounded.
Key Roughness Features
Key Roughness Features: Key roughness features that create diversity in flow velocity, depth, and energy dissipation patterns, tend to be less mobile than the streambed material, and are essential for fish passage.
Type: Key Roughness Feature type. Choices are random boulder and cobble, boulder and cobble clusters, boulder and cobble transverse ribs, log steps, other.
DSTAB: Median diameter in inches of stone or log making up the Key Roughness Feature primary element.
Feature Stability: Key Roughness Feature estimated stability. Choices are not stable - maintained up through 2-year discharge, stable - maintained up through 50-year discharge, or very stable - maintained beyond 50-year discharge.
Large Woody Debris
Diameter: Median diameter in inches of woody debris recruited locally or transported by the stream that is large enough to form features that influence stream morphology.
Length: Median length in feet of woody debris recruited locally or transported by the stream that is large enough to form features that influence stream morphology.
Amount: Qualitative description of amount of woody debris recruited locally or transported by the stream that is large enough to form features that influence stream morphology. Choices are none, abundant, moderate, or sparse.
Notes, Photographs, and Drawings
Additional Notes: Add any additional notes needed to fully describe stream morphology, culvert design, and culvert performance.
Photographs: Photographs and drawings documenting design intent and performance of a functioning culvert. Include photographs of inlet, outlet, interior treatments, outlet control devices, and stream morphology.