1. Hydrology

2. Step 1: Assess Riparian Resource Function Using PFC
5/14/2018
Step 1: Assess Riparian Resource Function Using PFC
1d. Complete PFC assessment
17 questions about attributes and processes
Reminder – PFC based on:
Water (hydrology),
Vegetation, and
Soil & landform (erosion/deposition)
Checklist answers: Yes, No, or N/A (sometimes)
Not “Liner”
Notes for “No’s”, Many (all?) “Yes’s”, e g. species list
Reminder – PFC is based on a 3-legged stool

3. Abandoned floodplain or terrace
Level area near a stream channel
Constructed by the stream
In the present climate
Flooded during moderate & high flow events
Should not be confused with terraces (abandoned floodplains) (adapted from Leopold 1994)
Valley flat
Abandoned floodplain or terrace
Definition of floodplain adapted from Leopold 1994.
Hill slope
Floodplain
Channel
Item #1: Floodplain inundation

4. Floodplain – Geologic feature being formed by the river in its present condition and climate

5. Bankfull Concept Information
Forest Service Stream Systems Technology Center (Stream Team) website for on-line training videos, can order CDs and DVDs:
Western U.S.
Northeastern U.S. (4 CDs)
Forested Streams Eastern U.S.
There are some great references available that discuss these concepts in much more detail that the IDT should consider reviewing as part of field work

6. Field Observations Build a case based on physical evidence
Series of depositional features at consistent elevations with similar substrate and veg components
Point bars at inside of meander bends,
Point bars often not well developed with low sinuosity,
Discontinuous alternating longitudinal bars parallel to the channel often most dependable indicator
Broad valley floors are almost always above bankfull
Bankfull Indicators (Moody et al. 2003, Odem and Moody 1999)

13. Item 1: Floodplain inundated frequently
Floodplain inundated in “relatively frequent events”
Purpose: To determine whether frequent flood flows are capable of spreading out on low-lying areas adjacent to the stream and thus provide for:
energy dissipation
sediment deposition
periodic flooding of vegetation, and
periodic infiltration of flood water to replenish base flows
1) Floodplain above bankfull is inundated in “relatively frequent” events _Deletiong above bankfull is not a change in meaning.
Purpose
The purpose of question 1 is to determine if the stream system being examined is supposed to have a floodplain, and if so, is it functioning appropriately regarding discharge and sediment. Most stream systems that are not highly confined support a floodplain landform. However, if the floodplain landform is not periodically flooded by the stream, it no longer functions as a floodplain. This may indicate that the feature is actually a terrace or it is non-functional (either insufficient discharge or overdeveloped channel geometry prevents a bankfull-floodplain relationship).
The floodplain provides additional capacity for the stream system to transport and store water and sediment. The magnitude and significance of the additional capacity depends on the spatial extent of the floodplain along with basin and stream systems characteristics. Vegetation often is an important player in the efficiency and longevity of floodplain function. Periodic flooding of the floodplain is often necessary to promote and sustain riparian vegetation and therefore is a key factor in determining the functional condition of the riparian system.
We need to define some terms that are used in the assessment. They are bankful, floodplain, and base flow.
Base flow is the depth of the water during the low flow time of the year, usually late summer and winter in this area.
Floodplain
Bankfull

14. Item 1: Floodplain is inundated in “relatively frequent” events
Flat, depositional surface adjacent to channel on:
Low gradient, meandering (“C” and “E” channels)
Moderate gradient “B” channels
Indicators of “No”
Incised channel
Enlarged channel
Vertical banks on inside of bend & at straight reaches
Upland vegetation on streambank
1) Floodplain above bankfull is inundated in “relatively frequent” events
A floodplain is recognized as a:
Flat, depositional surface adjacent to the channel, formed by sediments transported by the stream, and formed under the current climatic and hydrologic regime.
A floodplain is common on low-gradient, meandering streams, like “E” and “C” stream types, as well as some moderate gradient “B” channels.
Indicators of inaccessible floodplains could include:
Channel incision,
Vertical banks on inside of meander bend and along straight channel segments, and
Upland vegetation on streambanks where hydric vegetation is expected.

15. Terrace Floodplain Bankfull
Clover Creek is a good example of the stream channel, developed and active floodplain, and terraces. Here we see the bankful width and indication the stream is accessing the floodplain. Riparian vegetation grows through the sediment very rapidly and by the end of the season, it may be difficult to see any evidence of flooding.
Floodplain

16. Item 2: Beaver dams are stable
Purpose: Beaver dams are hydrologic modifiers. Stable dams can increase stability by attenuating flood flows, providing a source for base flows, storing sediment, raising water tables and expanding riparian areas.
Unstable dams can reduce stability by causing channel incision, increasing bank erosion, lowering water tables and decreasing the extent of the riparian zone when they fail.
Item 2 - Where beaver dams are present, are they stable?
Purpose
Beavers are key agents of riparian-wetland succession because they act as hydrologic modifiers. Stable dams can increase stability by attenuating flood flows, providing a source of base flows, storing sediment, raising water tables and increasing the extent of the riparian zone.
This question is important because beaver dams are blockages that change an area's site progression (see Figure 2 in TR ). A flowing stream can be changed overnight to an aquatic pond. If the dams are not maintained or captured by vegetation, over time, they might breach and unleash tremendous energies that usually result in degradation, such as channel incision, bank erosion, lowered water table, and contraction of the riparian area.
The purpose of this question is to document whether beaver dams are present, and if so, whether they are being actively maintained (stable).
Some dams are inactive, but stabilized by vegetation.

17. Item 2: Beaver dams are stable
Indicators of beaver activity
Fresh workings on dams
Available building materials and food supply
Indicators of dams at risk
Single dams
No signs of maintenance and repair
Confined valleys - no floodplain
Dams not anchored to banks
Large, flashy streams
Dams not stabilized by woody vegetation
Item 2: Beaver dams are stable
2) Beaver dams are stable
Beaver dams as hydrologic modifiers
Focus on stability
Indicators of beaver activity
Fresh workings on dams
Available building materials and food supply
Indicators of dams at risk
Single dams
Confined valleys - no floodplain
Large, flashy streams
No signs of maintenance and repair

18. 2: Beaver dams are stable
Examples of visual indicators
Dam construction material
Dams keyed into streambanks
Breaches
Visual indicators you can see and interpret in the field for a “no” answer:
Dams constructed out of sagebrush or other upland vegetative materials are usually not very stable because the vegetation cannot take root and grow (it is too wet for them) (ID example).
If the dams are not keyed into the streambanks by the beavers, high water will flow through that area and usually either wash out the bank or the beaver dam (CO example). Dams that have breached and material is not replaced, are not being maintained by the beavers and probably won’t be stable over time.
[Photo 1: Unknown. ID. Date. Beaver dam made of sagebrush. The beaver is actively working on the dam, but it is not expected to be stable in the long term, so answer “no.”.]
[Photo 2: Unknown, CO. 7/2000. Beaver dam is not keyed into the bank so there is a place for water to concentrate during high flow and wash out the streambank and the beaver dam. The answer is “no.”]
Yes No NA

19. Item 3:Sinuosity, gradient, and width/depth ratio, are in balance with the landscape setting (i.e., landform, geology, and bioclimatic region)
Purpose: To determine if the pattern, dimension, and profile of the stream are within the expected range, given its landscape position, hydrologic regime, and natural sediment load. Sinuosity, width/depth ratio, and gradient perform key roles in determining whether a stream can transmit water and sediment while managing erosive forces and remaining stable
Question 3 - Sinuosity, width/depth ratio and gradient are in balance with the landscape setting (i.e., landform, geology, and bioclimatic region)
Purpose -- To determine if the pattern, dimension, and profile of the stream are within the expected range, given its landscape position, hydrologic regime, and natural sediment load.
Sinuosity (pattern), width/depth ratio (dimension), and gradient (profile) play important roles in how well a stream dissipates energy. A decrease in stream length relative to valley length (sinuosity) results in a higher gradient, which increases velocities. Increased velocities accelerate erosion, which alters sinuosity, gradient, and width/depth ratios. To be in balance, a stream has to be near the shape and size expected for its setting.
Channel classification tools like Montgomery and Buffington (1993) or Rosgen (1996) describe a range of characteristics for a setting and make this question easier to answer.

20. Item 3:Sinuosity, gradient, and width/depth ratio, are in balance with the landscape setting (i.e., landform, geology, and bioclimatic region)
Question has three parts
Sinuosity
Width/Depth ratio
Gradient
All three must be "yes" for answer to be "yes"
Must be appropriate for site
Never NA
Item 3 - Sinuosity, width/depth ratio and gradient are in balance with the landscape setting (i.e., landform, geology, and bioclimatic region)
3) Sinuosity, width/depth ratio, and gradient are in balance with the landscape setting (i.e., landform, geology, and bioclimatic region)
Question has three parts
Sinuosity
Width/Depth ratio
Gradient
All three must be "yes" for answer to be "yes"
Must be appropriate for site

21. Sinuosity = Stream Length ÷ Valley Length
1.9 = 370' ÷ 195'
Q: Are the dimension, pattern, and profile in balance for the landscape setting.
A: Yes, the stream channel freely meanders in wide alluvial valley bottom to effectively reduce stream gradient and control stream energy.
The blue line indicating the existing channel provides a gradient or slope of 0.8% or moderately low. However, if the channel were straightened the slope or gradient would almost double to 1.5% or almost double the energy. This would cause much more energy to be exerted on the streambanks increasing the change or accelerated erosion.
Valley Gradient = 1.5%
Stream Gradient = 0.8%

22. Examples of visual indicators
3) Sinuosity, gradient, and width/depth ratio, are in balance with the landscape setting (i.e., landform, geology, and bioclimatic region)
Examples of visual indicators
Aerial photos help with sinuosity
Visual indicators you can see and interpret in the field:
As channel gradient and dominant particle size decreases, there is generally a corresponding increase in sinuosity.
Out in the field, it can be difficult to see long enough distances to answer the sinuosity part of this question. Aerial photos help in this regard.
[Photo 1: Walla Walla R, WA flood. Starting as early as 1904, riparian areas were cleared for farming and the channel straightened. Note the sinuosity of the thalweg (deepest part of the channel) during the flood which demonstrates the rivers natural tendency to meander.]
[Photo 2: Beaver Cr, OR, private land. 6/1985. Wide, low gradient valley bottom. In this landform and climate, expect high sinuosity, moderate to high width/depth ratio.]

23. 5/14/2018
3.) Sinuosity, gradient, and width/depth ratio, are in balance with the landscape setting (i.e., landform, geology, and bioclimatic region)
YES
Although not very sinuous, this channel does not have the potential to be very sinuous. Its step-pool structure is appropriate for the landscape setting in which it is found.

24. 4.) Riparian area is expanding or has achieved potential extent.
5/14/2018
Purpose: To document that a riparian area is recovering or has recovered. NO
Riparian areas can widen by either narrowing the channel, forming new vegetated floodplain out of old channel bottom areas, or by elevating the water table with resistance to fast flow. Recovering streams may do both. If the riparian areas is widening, but han not yet reached its potential the answer is yes. If they have quit widening, but have reached their potential, the answer would still be yes.
YES

25. 4) Riparian area is expanding or has achieved potential extent
Examples of visual indicators
Riparian-wetland community types expanded to valley edge
Stream narrowed
Upland plants dying or dead
Depositions being captured
Visual indicators you can see and interpret in the field for a “yes” answer:
Riparian-wetland community types expanding.
Upland plants dying or dead because the water table has risen and drowned them out.
Depositions from high flow events are being revegetated.
“No” answers would be just the opposite of the above. Feel free to add another slide with another photo to demonstrate that.
[Crow Cr, Caribou NF, ID. Date. The manna grass can grow up through > 1 inch sediment and will seed out within one year.]
Yes No NA

26. 5/14/2018
Item 5: Riparian impairment from the upstream or upland watershed is absent.
Notice how this question is worded so that all the positive responses are yes. The No picture has a question mark because bad watershed conditions are only part of the consideration. The real question is whether those watershed conditions are leading to riparian degradation such as rapid channel aggradation, dehydration, greatly increased peak flows that are accelerating erosion, etc.
NO?
YES

27. 5: Riparian impairment from the upstream or upland watershed is absent.
Visual indicators you can see and interpret in the field:
British Columbia, Canada example of similar catchments. Belgo Creek catchment is relatively undisturbed, Trapping Creek catchment has many roads which eroded or caused land slides during rain events which delivered excessive sediments to the channel. Both are expected to have single thread channels, yet Trapping Creek is braided because of the excessive sediments, and would get a “no’ answer.
[Photo 1: Trapping Cr, BC Photo shows a typical reach of disturbed catchment/watershed. Many roads have eroded or caused excessive land slides causing braiding. The answer is “no.”]
[Photo 2: Belgo Cr, BC Photo shows typical reach of relatively undisturbed catchment. The answer is “yes.”]
Trapping Cr BC 1996
Belgo Cr BC 1996
Yes No NA
Never NA
Yes No NA

28. Is there riparian degradation?
Purpose: To determine if riparian degradation is caused by a management within the riparian area (reach) or by environmental conditions or management outside the riparian area (reach).
Is there riparian degradation?
No riparian degradation observed.
Item 5 = “Yes”
Yes, riparian degradation observed
Degradation related to in situ activities
Item 5 = “No”
Yes No
Degradation related to upstream or upland factors
Walk through step-wise evaluation process. Point out:
If no riparian degradation is observed, then item 5 must by “yes.”
If riparian degradation is observed, then item 5 may be “yes” or “no,” depending on the source of the degradation.
If the source of the degradation is within the riparian area, item 5 is “yes.”
But when the source of degradation is outside the immediate riparian area, such as a reach farther upstream or the uplands, then item 5 is “no.”