FLOOD06399

• County: Jefferson
• Community: Buffalo Creek
• Basin: South Platte
• Title: Stream Channel Stabilization Techniques for the Buffalo Creek Reclamation Project
• Date: 8/20/1996
• Prepared For: USFWS
• Prepared By: Woodward-Clyde
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

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Woodward..clyde

Mr. JeffBruggink
u.s. Forest Service
August 20, 1996
Page 2

velocity at the bank where shear stresses may become small enough to allow coarse sediment
to settle out of the flow.

Vegetation also is less expensive than most structural methods, and it unproves the
conditions for v,.ildlife.

Factors to Consider in Usinl! Planted Vel!etation

The basic factors affecting streambank erosion control with planted vegetation are stream
flow and flow characteristics, bank geometry, site preparation and protection, vegetation
types, revegetation techniques, and plant procurement and costs. As discussed previously,
the use of best management practices in the upper watershed burn areas will reduce flows
and aid in vegetation establishment for target downstream channel protection efforts.

A mixture of grasses, forbs, shrubs, and trees should be used to provide a diversity of
wildlife habitats and soil protection. Some legumes should be used because of their
nitrogen-fixing attributes.

Plants should be positioned in various elevation zones of the bank based on their ability to
tolerate various durations of flooding and their attributes of dissipating current-energies.
These are discussed below:

Splash Zone. That portion of the bank between normal high-water and normal low-water
flow rates. This is the zone of highest stress.

Bank Zone. That portion of the bank usually above the normal high-water level; yet this site
is exposed periodically to erosive river currents, ice and debris movement, and traffic by
animals or humans,

Terrace Zone. That portion of the bank inland from the bank zone; it is usually not
subjected to erosive action of the river except during occasional flooding.

For the splash zone, only herbaceous semi-aquatic plants like reeds, rushes, and sedges are
suggested for planting. These types of plants can tolerate considerable flooding and are
more likely to live in this zone. In the bank zone, both herbaceous and
woody plants are used. These should still be quite flood tolerant and able to withstand
partial to complete submergence for as long as several weeks. The terrace zone is less

96OOOvsa.IA.E498 8119196(3~ PM)IMKT/48

Woodward-Clyde Consultants