1. Module 10/11 Stream Surveys
Stream Surveys – February 2004 Part 5 – Watershed Assessment

2. Objectives Students will be able to:
list characteristics used to describe floodplains.
categorize channel types and patterns of streams.
calculate the slope of a stream.
compare bankfull width and wetted width of streams.
list indicators of bankfull discharge.
categorize stream bank shapes.

3. Stream assessments Water quality Habitat Hydrologic Biological
Watershed
You could probably drop this slide, the next slide covers this

4. Watershed assessments
The upper Mississippi River watershed

5. Watershed Assessment Land use Current and historical pollution sources
Identify water uses, users, diversions, and stream obstructions

6. Floodplain Characteristics
Land use
Width
Active, inactive (incised), inactive (incised), anthropogenic (fill)
Width of riparian buffer zone

7. Stream morphology Channel type Channel pattern Substrate Slope
Sinuosity
Bankfull discharge
Riparian characteristics

8. Channel type Bedrock Colluvial Alluvial A. Cascade B. Step-pool
C. Plane-bed
D. Pool & riffle
E. Dune – ripple
Image: Montgomery & Buffington 1997, Figure 3
Colluvial Channel: Bed sediments are a result of mass wasting; not transported by the river. Common in small headwater streams
Alluvial Channel: Channel bed sediments transported by the river
Cascades: have “tumbling flow” due to dissipation of energy by large boulders in channel. High Gradient. Large bed materials are immobile during average flows while small grains are transported quickly.
Step-Pool: have longitudinal “steps” made of boulders and cobbles. High Gradient. Steps are removed by large floods and reconstructed when flood waters recede.
Plane-bed – moderate gradient streams that lack discrete bars. Typically have armored beds indicating that transport capacity > sediment supply
Pool & Riffle – low gradient streams undulating beds. Bar/pool riffle sequences.
Dune-ripple – low gradient streams with ripples or dunes in the bed. Sediment transport at most flows.

9. Channel Pattern Straight Sinuous (image not shown) Braided Meandering

10. Slope
Major determinant of river and stream form, structure, and performance.
Determined by measuring the rise of the stream water surface over a distance greater than 20 times the stream's width.

11. Sinuosity The ratio of stream length to valley length
A straight stream has a sinuosity of 1
Slide to be completed by 3/31/04

12. Bankfull Discharge
The stream discharge that fills the stream to the top of its banks before spilling onto the floodplain.
This stream, Chester Creek following a summer storm, has exceeded its bankfull width.

13. Bankfull Discharge Indicators: (from Harrelson, 1994)
height of depositional features (bars) indicate lowest possible level
change in vegetation (lower limit of perennial species)
slope changes along bank
change in particle size along bank
undercuts on bank
stain lines
Harrelson, C.C., C.L.Rawlins, and J.P. Potyondy Stream Channel Reference Sites: An illustrated guide to field technique. USDA Forest Service Technical Report RM pp.

14. Bankfull Discharge
Image:

15. Riparian Characteristics
Width of riparian zone
Buffer strip
Type of vegetation
Trees, bushes, and tall grass
Lawns
Bare soil and pavement
trees, bushes, and tall grass can contribute shade and cover for fish and wildlife and can provide the stream with needed organic material such as leaves and twigs. Lawns indicate that the stream's riparian zone has been altered, that pesticides and grass clippings are a possible problem, and that little habitat and shading are available. Bare soil and pavement might indicate problems with erosion and runoff. Looking upstream, provide this information for the left and right banks of the stream (from Stream Habitat Walk, EPA Stream Monitoring Manual)

16. Canopy cover Visual estimate Densiometer
Densiometer image from Forestry Suppliers

17. Stream bank shape
Types of streambank shapes The shape of the stream bank may include: •  Vertical or undercut bank- a bank that rises vertically or overhangs the stream. This type of bank generally provides good cover for macroinvertebrates and fish and is resistant to erosion. However, if seriously undercut, it might be vulne rable to collapse. •  Steeply sloping- a bank that slopes at more than a 30 degree angle. This type of bank is very vulnerable to erosion. •  Gradual sloping- a bank that has a slope of 30 degrees or less. This type of stream bank is highly resistant to erosion, but does not provide much streamside cover.
Artificial bank modifications include all artificial structural changes to the stream bank such as riprap (broken rock, cobbles, or boulders placed on earth surfaces such as the face of a dam or the bank of a stream, for protection against the action of the water) and bulkheads. Determine the approximate percentage of each bank (both the left and right) that is artificially covered by the placement of rocks, wood, or concrete. (March 2003-Text adapted from the USEPA Stream Habitat Walk;

18. Stream surveys - references
Techniques of Water-Resources Investigations Reports
National Field Manual for the Collection of Water-Quality Data
Rapid bioassessment protocols for wadeable streams
Also:
Oregon Watershed Assessment Manual